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The fall armyworm (FAW), Spodoptera frugiperda is a cold-sensitive species that overwinters in temperate climates without diapause. Overwintering in insects involves rapid cold hardening (RCH), supported by trehalose (TRE), which serves as an intermediate between glycogen (GLY) and glucose (GLU). However, both GLU and TRE help maintain homeostasis under stress. TRE is hydrolyzed by the enzyme trehalase (Treh) into GLU. This study retrieved Sf-Treh1a, Sf-Treh1b, and Sf-Treh2 from the FAW transcriptome analysis. RNA interference (RNAi) targeting these three Treh genes resulted in significant downregulation of mRNA levels and altered survival rates in RNAi-treated FAW larvae following RCH treatment. High-pressure liquid chromatography (HPLC) quantification of TRE and GLU in treated groups suggests that GLU is an essential component of the hemolymph for survival adaptation to cold conditions in S. frugiperda. This study reveals limited cold adaptability of FAW, as evidenced by lower glucose concentration levels. We found that FAW requires alternative molecules, in conjunction with glucose and trehalose for freeze tolerance and survivability. Our study aims to discover the molecular mechanisms that contribute to freeze tolerance in FAW by exploring the roles of trehalose, glucose, and glycogen. [ABSTRACT FROM AUTHOR]

Temperate winters are getting warmer, the length of the growing season is increasing and mid‐winter fluctuations of warm and freezing temperatures are more frequent. Although typically winter dormant, some herbaceous perennials can maintain or grow green leaves during the winter and more species may do so as winters become warmer. For wintergreen leaves to provide an advantage, they must be able to photosynthesize during the warm spells but also withstand freezing temperatures and fluctuations between the two conditions. To understand the leaf traits of wintergreen herbs, we studied three widely distributed perennial species: Bellis perennis, Plantago lanceolata and Trifolium repens. For contrast between winter and growing season leaves, we measured three common leaf economic traits (LDMC, SLA and leaf N content). To assess freezing tolerance, we measured the ice nucleation temperature and LT50 after frost exposure in winter leaves. To confirm photosynthetic ability, we measured photosynthetic efficiency (Fv/Fm value) in winter and late spring. Additionally, we surveyed the green and dead leaf coverage for herbaceous species in a lawn community from winter to early summer (four surveys in total). We used our observations to determine phenological categories and compared them to historical observations of wintergreenness. All three species had denser leaves with lower nitrogen content in winter than in the growing season and relatively high tolerance of freezing temperatures (average of −8°C ice nucleation temperature and −15°C LT50). Both winter and growing season leaves were capable of photosynthesis, but the efficiency was greater for growing season leaves. In the community survey, a majority of the plant species had green leaves in winter, and many were without dead winter leaves. Many wintergreen herbs had previously been labelled ‘summer green’. With these initial investigations into the traits and phenology of wintergreen herbs, we confirm that wintergreen leaves have different traits from typical growing season leaves and are capable of both photosynthesis and freezing tolerance. Wintergreen herbs have a broad range of phenological strategies and differ from observations 20 years ago. In many temperate regions, winter is becoming a new growing season and thus should be included in phenological studies. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Western Monarch butterflies (Danaus plexippus) migrate from inland breeding ranges to coastal overwintering grounds in California. Given that migratory individuals may make multi-scale habitat selection decisions, we considered a multi-scale species distribution model (SDM) using range-wide climatic and local landscape-level predictors of migratory and overwintering habitat and community-science presence data. The range-wide model output was included as a predictor in the local-scale model, generating multi-scale habitat suitability. The top range-wide predictor was the minimum temperature in December, contributing 83.7% to the model, and was positively associated with presence. At the local scale, the strongest predictors of presence were the range-wide output and percent coverage of low and medium levels of development, contributing > 95%, with 61–63% from the range-wide output, with local-scale suitability coinciding with the California coastal zones. Development's positive association with overwintering monarch presence was counterintuitive. It is likely that our local-scale model is overfit to these development zones, but it is unclear whether this overfitting resulted from modeler choices, monarchs overwintering close to human development, biased detection near human development, or a combination of these factors. Therefore, alternative approaches to collecting local-scale attribute data are suggested while recognizing the primacy of climate in restricting overwinter sites. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the impact of climate change on the phenology of Carposina sasakii in China using historical data. The findings reveal that overwintering adults' first occurrence and population peak dates have generally advanced in eastern, northwestern, and northern regions, except for a delay in Jilin. For first-generation adults, first occurrence dates have shifted earlier in northeast, east, and central China but delayed in northwest and northern parts. Significant delays were observed in population peaks and end occurrences in provinces like Gansu, Shaanxi, and Liaoning. Pearson correlation analyses confirm spatial heterogeneity in C. sasakii's responses to warming temperatures. These insights are crucial for monitoring and managing peach fruit moth populations amidst climate change. It is widely recognized that the phenology of insects, of which the life activities are closely tied to temperature, is shifting in response to global climate warming. This study aimed to investigate the impacts of climate change on the phenology of Carposina sasakii Matsumura, 1900 (Lepidoptera: Carposinidae) across large temporal and spatial scales, through collecting and systematically analyzing historical data on the pest's occurrence and population dynamics in China. The results showed that for overwintering adults, the first occurrence date in eastern, northwestern, and northern China has significantly advanced, along with the population peak in eastern and northwestern China. At the provincial level, the population peak date in Shandong province has also moved significantly earlier, as well as the population peak date in Shandong and Shaanxi and the end occurrence date in Ningxia. However, the population peak date in Jilin has experienced a delayed trend. For first-generation adults, the first occurrence date in northeastern, eastern, and central China has notably advanced, while the first appearance date in northwestern and northern China has significantly delayed. Additionally, the population peak in northwestern China has experienced significant delays, along with the final occurrence in northeastern and northwestern China. At the provincial level, the first occurrence date in Liaoning, Shandong, and Shanxi has significantly advanced, while Hebei has demonstrated a significant delay. The population peak time in Gansu and Shaanxi has displayed significant delays, and the end occurrence date in Liaoning, Shanxi, and Shaanxi has also shown significant delays. Furthermore, these findings integrated with the Pearson correlation results reveal spatial heterogeneity in C. sasakii's phenological responses to climate warming at both regional and provincial scales. The phenology of C. sasakii and their changing patterns with climate warming vary by geographical location. This study provides valuable information for the future monitoring, prediction, and prevention of peach fruit moths in the context of climate warming. [ABSTRACT FROM AUTHOR]

Seasonal variability in environmental conditions is a strong determinant of animal migrations, but warming temperatures associated with climate change are anticipated to alter this phenomenon with unknown consequences.We used a 40‐year fishery‐independent survey to assess how a changing climate has altered the migration timing, duration and first‐year survival of juvenile bull sharks (Carcharhinus leucas).From 1982 to 2021, estuaries in the western Gulf of Mexico (Texas) experienced a mean increase of 1.55°C in autumn water temperatures, and delays in autumn cold fronts by ca. 0.5 days per year. Bull shark migrations in more northern estuaries concomitantly changed, with departures 25–36 days later in 2021 than in 1982. Later, migrations resulted in reduced overwintering durations by up to 81 days, and the relative abundance of post‐overwintering age 0–1 sharks increased by >50% during the 40‐year study period.Yet, reductions in prey availability were the most influential factor delaying migrations. Juvenile sharks remained in natal estuaries longer when prey were less abundant. Long‐term declines in prey reportedly occurred due to reduced spawning success associated with climate change based on published reports. Consequently, warming waters likely enabled and indirectly caused the observed changes in shark migratory behaviour.As water temperatures continue to rise, bull sharks in the north‐western Gulf of Mexico could forgo their winter migrations in the next 50–100 years based on current trends and physiological limits, thereby altering their ecological roles in estuarine ecosystems and recruitment into the adult population. It is unclear if estuarine food webs will be able to support changing residency patterns as climate change affects the spawning success of forage species.We expect these trends are not unique to the western Gulf of Mexico or bull sharks, and migratory patterns of predators in subtropical latitudes are similarly changing at a global scale. [ABSTRACT FROM AUTHOR]

Summary: Spring regrowth in temperate perennials relies on renewal buds, which form a key component in the shoot growth cycle. Still, we possess almost no information on these renewal buds, which is becoming more pressing with the current climate change. Most existing studies concentrated on easy‐to‐study aboveground buds of woody plants, whose morphology has largely been linked to frost protection. It is not clear to what extent these findings apply also to herbaceous species.We therefore examined protective traits and preformation of winter renewal buds in 379 species of temperate herbs, and tested how these traits are distributed across the phylogeny and related to other bud bank and whole‐plant traits.We identified a major gradient from few, large, highly preformed, scale‐covered buds associated with larger belowground storage organs deep in the soil, to small, numerous, less preformed, and naked buds near the soil surface.Belowground renewal buds of temperate herbs show several distinct strategies for winter survival and spring regrowth that might affect their response to changing winter and early spring conditions. Renewal bud traits are driven not only by frost protection but also by protection of the apical meristem from mechanical disturbance in the soil. [ABSTRACT FROM AUTHOR]

Rice stripe mosaic virus (RSMV) is an emerging pathogen which significantly reduces rice yields in the southern region of China. It is transmitted by the leafhopper Recilia dorsalis, which overwinters in rice fields. Our field investigations revealed that RSMV infection causes delayed rice heading, resulting in a large number of green diseased plants remaining in winter rice fields. This creates a favorable environment for leafhoppers and viruses to overwinter, potentially contributing to the rapid spread and epidemic of the disease. Next, we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant. A rice heading‐related E3 ubiquitin ligase, Heading date Associated Factor 1 (HAF1), was found to be hijacked by the RSMV‐encoded P6. The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins, HEADING DATE 1 and EARLY FLOWERING3, leading to a delay in rice heading. Our results provide new insights into the development regulation‐based molecular interactions between virus and plant, and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies. [ABSTRACT FROM AUTHOR]

Understanding and characterizing how insects tolerate low temperatures is important for predicting their overwintering survival and subsequent geographic spread. This study characterized the cold tolerance of two members of the Rhagoletis genus (Diptera: Tephritidae) in Colorado, USA. Pupae were collected from the infested fruits in late summer and early fall. For the first time, we show that the rosehip fly Rhagoletis basiola Osten Sacken is freeze‐avoidant; overwintering pupae could supercool to temperatures as low as −26°C and survive. Interestingly, the temperature at which ice forms (supercooling point; SCP) did not vary between R. basiola at high (c. 2900 m above sea level [m a.s.l.]) and lower (c. 1650 m a.s.l.) elevations. We also report the apple maggot R. pomonella Walsh infesting an unusual host fruit, the Dolgo crabapple, in close proximity to infested hawthorn trees. R. pomonella infesting hawthorn fruits and crabapples had similar SCPs and survived temperatures as low as −21°C. Pupae from both host fruits also survived prolonged exposure (2 weeks or more) to mild low temperatures (0 to −5°C). Further study into the mechanisms underlying the impressive and conserved cold tolerance of R. pomonella and R. basiola is an interesting avenue for future research. [ABSTRACT FROM AUTHOR]

Organisms face the fundamental ecological question of when to switch resources from growth to reproduction or allocate resources between the two. Social wasps, including Vespula species (the yellowjackets), must crucially decide to transition from colony growth to reproductive production before the onset of winter. The timing of this transition could be influenced by worker numbers and environmental factors that affect the fitness of the colony. Early initiation of reproductive production has the advantage that a few reproductives can emerge if the colony collapses prematurely. In contrast, once reproductive production begins, nest growth terminates and the increase of future reproductives should be limited. This study investigated the group decision-making process regarding when and under what circumstances Vespula shidai initiates its reproductive phase. During the early reproductive period, we estimated the number of workers and new queens that emerged from the meconia in the cells. Significantly, a positive correlation was observed between the number of workers and the production of new queens during the early reproductive period. To examine the benefits of early reproduction, we reared V. shidai colonies in a plastic greenhouse, allowed males and new queens to fly and mate freely, and allowed the queens to begin overwintering at their timing. In our experimental environment, new queens that emerged earlier in the reproductive period had a higher survival rate during overwintering and higher dry and fat weights in the following spring. The higher dry and fat weights of the queens suggested better survival during the founding phase of the nest. [ABSTRACT FROM AUTHOR]

Abstract The fall armyworm (FAW), Spodoptera frugiperda is a cold-sensitive species that overwinters in temperate climates without diapause. Overwintering in insects involves rapid cold hardening (RCH), supported by trehalose (TRE), which serves as an intermediate between glycogen (GLY) and glucose (GLU). However, both GLU and TRE help maintain homeostasis under stress. TRE is hydrolyzed by the enzyme trehalase (Treh) into GLU. This study retrieved Sf-Treh1a, Sf-Treh1b, and Sf-Treh2 from the FAW transcriptome analysis. RNA interference (RNAi) targeting these three Treh genes resulted in significant downregulation of mRNA levels and altered survival rates in RNAi-treated FAW larvae following RCH treatment. High-pressure liquid chromatography (HPLC) quantification of TRE and GLU in treated groups suggests that GLU is an essential component of the hemolymph for survival adaptation to cold conditions in S. frugiperda. This study reveals limited cold adaptability of FAW, as evidenced by lower glucose concentration levels. We found that FAW requires alternative molecules, in conjunction with glucose and trehalose for freeze tolerance and survivability. Our study aims to discover the molecular mechanisms that contribute to freeze tolerance in FAW by exploring the roles of trehalose, glucose, and glycogen.

Culicoides biting midge species (Diptera: Ceratopogonidae) of the Obsoletus Group and the Pulicaris Complex are considered the major vectors of bluetongue and Schmallenberg viruses in Europe. Overwintering strategies of these arboviruses are controversially discussed, with the ongoing activity of vector species and a non‐disrupted transmission cycle during winter being a plausible explanation. Although data on Culicoides winter activity are relatively scant, a seasonal vector‐free period (SVFP), during which adult Culicoides are not or hardly active, is questionable. To determine winter activity and define SVFPs according to the EU Commission Regulation No 1266/2007, adult Culicoides were trapped weekly with UV‐light traps from October to April 2019/2020 and 2020/2021 inside and outside stables on 16 farms throughout Germany. Temperature measurements were taken regularly at each trapping site since the temperature is a known driver of biting midge activity. In 960 indoor and outdoor catches, 32,377 Culicoides were trapped, with 90.9% of them belonging to the Obsoletus Group, 6.1% to the Pulicaris Complex and 3.0% to 'other Culicoides' according to morphological identification. The majority (61.3%) of Culicoides were trapped indoors, with substantial numbers of specimens collected from October to December, in March and in April, and only a few or no specimens in January and February. Obsoletus Group biting midges were active indoors for almost the entire winter. Outdoors, Culicoides numbers decreased from October to December, few or no specimens were caught from January to March, and high numbers were captured in April. Of the collected Culicoides, 2028 were blood‐fed, of which 94.6% were trapped in the stables. The indoor SVFP, although calculated for blood‐fed instead of parous females, lasted for almost 4 months (late November until mid‐March) in winter 2019/2020 and 2 months (January and February) in winter 2020/2021. The outdoor SVFPs covered almost the entire study period in both winters, with slight differences between the onsets and the ends. The Culicoides activity significantly depended on temperature. Specimens of the Obsoletus Group were caught at an average temperature of 7.4°C (minimum 0.3°C) and of the Pulicaris Complex at an average temperature of 10.3°C (minimum 1.2°C). These temperatures were reached inside the stables over more extended periods than outside. The average indoor temperatures were 1.2 K higher than the average outdoor temperatures, although absolute temperature differences of up to 9.0 K were recorded. Based on Culicoides activity, the results of the present study indicate an almost continuous potential for virus transmission in winter within livestock houses. [ABSTRACT FROM AUTHOR]

Aphids (Hemiptera: Aphididae) are known for their remarkable adaptability and diversity, with most species richness found in temperate regions and worldwide distribution. Climate change is expected to affect aphid populations, especially their overwintering success. In this study, we aimed to investigate the diversity of wheat aphid populations and dynamics of overwintering success of aphids across early to late sown wheat. We employed both morphological and molecular techniques to distinguish and characterize six aphid species: Rhopalosiphum maidis, Rhopalosiphum rufiabdominalis, Rhopalosiphum padi, Sitobion avenae, Schizaphis graminum, and Metopolophium dirhodum. Among these, Rhopalosiphum maidis and Rhopalosiphum rufiabdominalis found to affect at the vegetative stage of the crop, while the other species were found to affect at the reproductive stage. Notably, we observed that aphid populations were more abundant on early-sown genotypes and decreased with normal and late sowing dates. The differences in peak aphid populations among different sowing dates revealed that delayed in sowing dates minimize aphid attack by producing asynchrony between host plant and the aphid population. Conversely, the environmental factors such as temperature, relative humidity, rainfall and bright sunshine hours varied across the sowing dates where early sown wheat genotypes are exposed to lower temperatures at vegetative stage and late sown genotypes are susceptible to higher temperatures at the terminal stage. These changes in environmental factors across different sowing dates affected the timing and duration of aphid life stages, including overwintering success. Nevertheless, understanding the diversity and distribution of aphid species in wheat crop and its response to different sowing dates could be crucial for developing effective pest management strategies, particularly in the context of climate change. Overall, this study highlights the need for ongoing aphid monitoring and adaptive management approaches that account for the dynamic interactions between pests, crops and the environment. [ABSTRACT FROM AUTHOR]

Abstract Korla pear has a unique taste and aroma and is a breeding parent of numerous pear varieties. It is susceptible to Valsa mali var. pyri, which invades bark wounded by freezing injury. Its genetic relationships have not been fully defined and could offer insight into the mechanism for freezing tolerance and disease resistance. We generated a high-quality, chromosome-level genome assembly for Korla pear via the Illumina and PacBio circular consensus sequencing (CCS) platforms and high-throughput chromosome conformation capture (Hi-C). The Korla pear genome is ~ 496.63 Mb, and 99.18% of it is assembled to 17 chromosomes. Collinearity and phylogenetic analyses indicated that Korla might be derived from Pyrus pyrifolia and that it diverged ~ 3.9-4.6 Mya. During domestication, seven late embryogenesis abundant (LEA), two dehydrin (DHN), and 54 disease resistance genes were lost from Korla pear compared with P. betulifolia. Moreover, 21 LEA and 31 disease resistance genes were common to the Korla pear and P. betulifolia genomes but were upregulated under overwintering only in P. betulifolia because key cis elements were missing in Korla pear. Gene deletion and downregulation during domestication reduced freezing tolerance and disease resistance in Korla pear. These results could facilitate the breeding of novel pear varieties with high biotic and abiotic stress resistance.

The purpose of the study was to evaluate the adaptive properties of winter wheat varieties in the competitive variety testing, to identify the best ones for the soil and climatic conditions of the Udmurt Republic based on a set of economically valuable traits. In 2020–2023 seven winter wheat varieties were tested in comparison with the standard ‘Volzhskaya K’ and the variety ‘Moskovskaya 39’. The adaptability of the varieties was determined according to the method of A.V. Kilchevsky and L.V. Khotyleva (1985), S.A. Eberhart, W.A. Russell (1966). Weather conditions during the years of study (drought in 2021 and 2023, excessive moisture in 2022) made it possible to evaluate varieties for drought resistance, determine their resistance to lodging, and the ability to use favorable conditions to form high yields. It was revealed that the most adapted varieties were ‘Cheberina’ and ‘26.12/6’, in 2021–2023 they formed the highest yield (50.0–50.1 hwt/ha) and provided a significant increase of 5.5–5.6 hwt/ha to the standard variety ‘Volzhskaya K’. These varieties significantly exceeded the standard variety in general adaptive capacity (GAC). There was found that the varieties ‘Lyubava’, ‘2.05/3’ and ‘Cheberina’ were the most valuable breeding varieties that combined high productivity with a stable yield. The varieties ‘Cheberina’, ‘26.12/6’, ‘Volzhskaya K’, ‘A-332/2’ were highly responsive to improved environmental conditions (bi > 1). Based on the study results, the adaptable, highly productive variety ‘Cheberina’ was sent to the state variety testing. There has been established that the variety forms a strong elastic stem of medium height, resistant to lodging, and increases ear weight and length, and its grain content in favorable conditions of the spring-summer period. An estimation of disease infection during the spring-summer growing season in 2022 showed that the variety possesses complex resistance to powdery mildew, leaf rust, and blotch of an ear and leaves. The variety formed grain of the third class with such indicators as 66 % of kernel hardness, 779 g/l of grain nature weight, 28 % of gluten of the first quality group, 12.8 % of protein in grain.

Invasive alien species are currently a major ecological problem. One such species is stone moroko, Pseudorasbora parva (Gobionidae), which has only been found to date in natural or agricultural water bodies (lakes, rivers and streams, carp ponds). Therefore, the current study is the first description of stone moroko in urban green areas (Warsaw, Poland). The fish were caught with a hydrobiological net. Four catches were conducted in ponds located in Morskie Oko Park (pond 1) and the Saxon Garden (pond 2) – two in fall and two in the spring, while two spring catches were conducted in Dolinka Służewska Park (stream). The population in pond 2 apparently survived the winter, and the fish caught in June displayed visible signs of sexual dimorphism and were significantly larger (average body mass: 1648 ± 1123 mg; range: 460–6090 mg) than those caught in the pond in the two fall samplings (404 ± 122 mg; 154–729 mg). After recording substantial numbers of specimens in the fall, no fish were caught in pond 1 during either of the spring catches, while only a few moroko were caught in the stream in April (1212 ± 869 mg; 454–2901 mg) and none were caught in June. Throughout the study, 59 specimens were caught in pond 1, 74 in pond 2, and 7 in the stream.

Abstract The flavivirus West Nile Virus (WNV), which is transmitted by mosquitoes, poses a significant threat to both humans and animals, and its outbreaks often challenge public health in Europe and other continents. In recent years, there is an increasing trend of WNV incidence rates across several European countries. However, whether there is a year-round circulation or seasonal introduction has yet to be elucidated. Real-time polymerase chain reaction (PCR) identified WNV-positive Culex pipiens mosquitos in 6 out of 146 pools examined in winter 2022 that correspond to three out of the 24 study areas, located in two coastal regions units in Attica, Greece. Spatial dispersion of the six positive pools in the same region suggests a clustered circulation of WNV during the winter of 2022. This is the first study that documents the identification of WNV in Cx. pipiens populations, captured in adult traps during winter period. Our findings underscore the need to extend entomological surveillance programs to include the winter period, specifically in temperate climates and historically affected areas by WNV. Graphical Abstract

Producing leek seeds without replanting one-year-old plants is cheaper and more practical, but can be risky in climates with cold winters. This research aimed to assess whether accelerating the planting of seedlings and using Fulvohumin fertilizer, containing, among others, humic acids can make such production less risky. Three dates were used for planting leek seedlings: April 10, April 25, and May 10. Fulvohumin was used presowing, foliarly, and both. Both factors significantly improved seed production. The best results were obtained at the earliest planting date, as the plants were strong and best prepared for the generative phase and the frost period. Fulvohumin significantly improved growth and development parameters, mainly when used before sowing and as foliar application. In the best combination, with two applications of fertilizers, the seed yield increased by 39%, compared to the control (without Fulvohumin fertilization), and the seed yield of plants planted on April 10 was 17% higher compared to plants planted on April 25 (considered as standard) and 39% higher than those planted on May 10. Seed yield varied in the three subsequent years of the study, but each year, the planting date and Fulvohumin had a similar effect on seed yield.

Bumblebees are key pollinators with gut microbiotas that support host health. After bumblebee queens undergo winter diapause, which occurs before spring colony establishment, their gut microbiotas are disturbed, but little is known about community dynamics during diapause itself. Queen gut microbiotas also help seed worker microbiotas, so it is important that they recover post‐diapause to a typical community structure, a process that may be impeded by pesticide exposure. We examined how bumblebee queen gut microbiota community structure and metabolic potential shift during and after winter diapause, and whether post‐diapause recovery is affected by pesticide exposure. To do so, we placed commercial Bombus impatiens queens into diapause, euthanizing them at 0, 2 and 4 months of diapause. Additionally, we allowed some queens to recover from diapause for 1 week before euthanasia, exposing half to the common herbicide glyphosate. Using whole‐community, shotgun metagenomic sequencing, we found that core bee gut phylotypes dominated queen gut microbiotas before, during and after diapause, but that two phylotypes, Schmidhempelia and Snodgrassella, ceased to be detected during late diapause and recovery. Despite fluctuations in taxonomic community structure, metabolic potential remained constant through diapause and recovery. Also, glyphosate exposure did not affect post‐diapause microbiota recovery. However, metagenomic assembly quality and our ability to detect microbial taxa and metabolic pathways declined alongside microbial abundance, which was substantially reduced during diapause. Our study offers new insights into how bumblebee queen gut microbiotas change taxonomically and functionally during a key life stage and provides guidance for future microbiota studies in diapausing bumblebees. [ABSTRACT FROM AUTHOR]

Previous studies of overwintering migratory birds in neotropical environments have found that species co-occur in the same habitats despite high diet overlap. Hence, discovering subtle diet differences within habitats can help explain patterns in bird species diversity. The Yucatan Peninsula in Mexico is an important region for overwintering migratory birds, but little is known about how habitat differences in food resources contribute to bird diversity. To address the knowledge gap, we compared the degree of overlap in the diet of all terrestrial migratory birds within and between mangrove and tropical dry forests on the Yucatan Peninsula's northern coast. We collected data on the consumption of food items through direct observation of birds feeding on four transects in each habitat every week (12 weeks) during the non-breeding season (i.e., overwinter, December-February). We recorded 19 species, 15 species in mangrove and 15 species in forest, with 11 of those found in both habitats. In both habitats, diet overlap was high. However, species present only in the tropical dry forest had less overlap than species occurring in both habitats, indicating that diet specialization might restrict the range of habitats that a species can occupy. On the other hand, species present only in the mangrove had similar diet overlap to species present in both habitats. The diet variation that did exist was greater within than between habitats possibly due to intraspecific diet differences among different geographic locations. Although small, within-habitat diet differences might be key to allowing species to coexist locally in the Yucatan, thus supporting studies demonstrating a similar mechanism in other neotropical regions. More generally, the information we provide on bird diet can be used to discover whether threats like anthropogenic development precipitate species loss via altering the resource base upon which birds rely. [ABSTRACT FROM AUTHOR]

Diapause is a strategy in insects to mitigate seasonal stress and synchronize lifecycles with favorable times. Forests are 3D, dynamic ecosystems with contrasting microhabitats where numerous insects enter diapause and the duration of diapause affects their phenology. Ecologically important forest insects, like defoliators, bark breeders, or soil/litter-dwelling species have diverse diapause strategies. Anthropogenic change, like climate change and urbanization, has and will have substantial impacts on forest insects. Some species may increase their impact on ecosystems, while that of others may be reduced. Understanding how climate change or urbanization factors, like artificial light at night and the urban-heat-island effect, affect diapause may help develop generalizable rules to predict which species will show population expansion and which are likely to contract. Insects have major impacts on forest ecosystems, from herbivory and soil-nutrient cycling to killing trees at a large scale. Forest insects from temperate, tropical, and subtropical regions have evolved strategies to respond to seasonality; for example, by entering diapause, to mitigate adversity and to synchronize lifecycles with favorable periods. Here, we show that distinct functional groups of forest insects; that is, canopy dwellers, trunk-associated species, and soil/litter-inhabiting insects, express a variety of diapause strategies, but do not show systematic differences in diapause strategy depending on functional group. Due to the overall similarities in diapause strategies, we can better estimate the impacts of anthropogenic change on forest insect populations and, consequently, on key ecosystems. [ABSTRACT FROM AUTHOR]

The family Cimicidae comprises ectoparasites feeding exclusively on the blood of endothermic animals. Cimicid swallow bugs specifically target swallow birds (Hirundinidae) and their nestlings in infested nests. Bugs of the genus Oeciacus are commonly found in mud nests of swallows and martins, while they rarely visit the homes of humans. Although—unlike other cimicid species—the house martin bug Oeciacus hirundinis has never been reported as a vector of zoonotic pathogens, its possible role in arbovirus circulation in continental Europe is unclear. Samples of O. hirundinis were therefore collected from abandoned house martin (Delichon urbicum) nests in southern Moravia (Czech Republic) during the 2021/2022 winter season and checked for alpha-, flavi- and bunyaviruses by RT-PCR. Of a total of 96 pools consisting of three adult bugs each, one pool tested positive for Usutu virus (USUV)-RNA. Phylogenetic analysis showed that the virus strain was closely related to Italian and some Central European strains and corresponded to USUV lineage 5. The detection of USUV in O. hirundinis during wintertime in the absence of swallows raises the question for a possible role of this avian ectoparasite in virus overwintering in Europe. [ABSTRACT FROM AUTHOR]

Background and Aims Turions are vegetative, dormant overwintering organs formed in aquatic plants in response to unfavourable ecological conditions. Contents of cytokinin (CK), auxin metabolites and abscisic acid (ABA) as main growth and development regulators were compared in innately dormant autumnal turions of 22 aquatic plant species of different functional ecological or taxonomic groups with those in non-dormant winter apices in three aquatic species and with those in spring turions of four species after their overwintering. Methods The hormones were analysed in miniature turion samples using ultraperformance liquid chromatography coupled with triple quadrupole mass spectrometry. Key Results In innately dormant turions, the total contents of each of the four main CK types, biologically active forms and total CKs differed by two to three orders of magnitude across 22 species; the proportion of active CK forms was 0.18–67 %. Similarly, the content of four auxin forms was extremely variable and the IAA proportion as the active form was 0.014–99 %. The ABA content varied from almost zero to 54 µmol kg−1 dry weight and after overwintering it usually significantly decreased. Of all functional traits studied, hormone profiles depended most on the place of turion sprouting (surface vs bottom) and we suggest that this trait is crucial for turion ecophysiology. Conclusions The key role of ABA in regulating turion dormancy was confirmed. However, the highly variable pattern of the ABA content in innately dormant and in overwintered turions indicates that the hormonal mechanism regulating the innate dormancy and its breaking in turions is not uniform within aquatic plants. [ABSTRACT FROM AUTHOR]

The flavivirus West Nile Virus (WNV), which is transmitted by mosquitoes, poses a significant threat to both humans and animals, and its outbreaks often challenge public health in Europe and other continents. In recent years, there is an increasing trend of WNV incidence rates across several European countries. However, whether there is a year-round circulation or seasonal introduction has yet to be elucidated. Real-time polymerase chain reaction (PCR) identified WNV-positive Culex pipiens mosquitos in 6 out of 146 pools examined in winter 2022 that correspond to three out of the 24 study areas, located in two coastal regions units in Attica, Greece. Spatial dispersion of the six positive pools in the same region suggests a clustered circulation of WNV during the winter of 2022. This is the first study that documents the identification of WNV in Cx. pipiens populations, captured in adult traps during winter period. Our findings underscore the need to extend entomological surveillance programs to include the winter period, specifically in temperate climates and historically affected areas by WNV. [ABSTRACT FROM AUTHOR]

This study was performed to investigate the seasonal variations in the emergence of the Chestnut Tiger Butterfly (Parantica sita niphonica) in a Marsdenia tomentosa population on Mt. Takatsuka in Minamiboso-City, Chiba Prefecture, Japan, between February 2006 and April 2015. There were two main periods of emergence per year: the overwintering generation, in which eggs were laid from mid-October to mid-December, with the larvae growing until April of the following year; and the first generation for which eggs were laid from early May to late June, with the larvae growing until early July. In some years, a second generation occurred between the first and overwintering generations. These results were compared with those of previous studies conducted in Kanagawa Prefecture and the northern Kanto region. In Kanagawa Prefecture, the overwintering generation and the first and second generations were confirmed, as in Chiba Prefecture, while the second generation was found infrequently in northern Kanto region. The growth of M. tomentosa on Mt. Takatsuka was investigated simultaneously with the larval survey. The tops of these plants on Mt. Takatsuka withered in summer. Neither flowering nor fruiting was observed on Mt. Takatsuka. [ABSTRACT FROM AUTHOR]

In response to global warming, the distribution ranges of numerous insect species have been reported to have expanded to higher latitudes and/or elevations throughout the world. In this study, rearing experiments of the cycad blue butterfly, Luthrodes pandava, which has undergone range expansion around the Japanese archipelago, were performed by simulating the temperature and photoperiod conditions of three sites at different latitudes around Japan. Using winter AMeDAS data for temperature conditions in Ishigaki City, Makurazaki City, and Kushimoto Town (Shionomisaki) from 2006 to 2015, the potential for overwintering in this species was tested. The results showed that 54--93% of individuals emerged as adults under conditions prevalent in Ishigaki. However, none of the larvae pupated and all died under conditions prevalent in Makurazaki and Shionomisaki. The findings show that this species can overwinter to the south of Okinawa, but not on the mainland north of Kyushu. Increased summer temperatures were also simulated, and individuals were reared under three conditions. Using AMeDAS data for August (summer) in Sakai City, central Japan from 2006 to 2015, the development of this species was examined under the original data (average conditions), original+2°C, and original+4°C. The results showed that more than 90% of individuals emerged as adults under all conditions. From the results of this study, if winter temperatures increase due to global warming, the northern distribution limit of overwintering populations of this species is expected to expand northward, the flying season will be extended, and populations will increase. [ABSTRACT FROM AUTHOR]

Cold temperatures can cause injury and death, and thermal tolerance influences organismal abundance, distribution, and physiology. We characterized cold tolerance and supercooling point (SCP) in the broadly distributed jumping spider Phidippus audax (Hentz, 1845). We found that P. audax is freeze-avoidant, surviving chilling but not freezing. Freeze-avoidant organisms can reduce harm by lowering their supercooling point (SCP), the temperature at which they freeze. We assayed fall/winter SCP in field-acclimated spiders from Michigan and compared lab-acclimated spiders from Texas, Oklahoma, and Michigan. Field-acclimated Michigan spiders decreased their SCP from –4.7 °C in September to –12.9 °C in November. In the lab, Michigan spiders had the lowest SCP (–7.65 °C) followed by Oklahoma (–6.21 °C) and Texas (–5.50 °C). In December and January, nearly all the spiders from Texas and Oklahoma died in the simulated freezing conditions while the Michigan spiders survived at high rates, further suggesting that the Michigan spiders were hardiest followed by Oklahoma and Texas. The lab-acclimated spiders did not consistently reduce their SCP from October to December. Smaller spiders had lower SCPs than larger spiders, and the Michigan spiders were significantly smaller than those from Texas or Oklahoma, suggesting that smaller overwintering size or delayed molting to mature size/sexual maturity may be favored by selection in colder climates. This could help explain differences in size and life cycle between northern and southern P. audax, as well as a previously described trend for smaller spiders to be more common in colder areas or Europe. [ABSTRACT FROM AUTHOR]

Frozen water bodies provide a physiological challenge to fauna by physically limiting access to atmospheric oxygen. To tolerate low temperatures, reptiles use brumation as a physiological strategy in winter. Cryptodira vary in their tolerance to freezing conditions but the extent of tolerance in pleurodirans is largely unknown. Australia's freshwater turtles inhabit warmer regions with less severe winters and have well‐developed mechanisms to cope with high temperatures and drying waterbodies, rather than extreme cold tolerance. Chelodina longicollis is a widespread Australian freshwater turtle species that tolerates high temperatures and desiccation during hot, dry periods while also undergoing brumation during winter months. Despite extensive research, limited observations exist on their behaviour during severe winter periods at the extremes of their range. In an 11‐month tracking study, we monitored adult C. longicollis, noting their movements, locations, and temperature weekly. We observed an adult female C. longicollis which, during a seven‐month period within a single creek pool, survived brumation in extreme cold water including a 15‐day period of total freezing of the surface water. After the ice melted following a rain event, the turtle was recaptured alive. This marks the first observation of brumation for an Australian chelid species under ice. [ABSTRACT FROM AUTHOR]

Simple Summary: There are differences in the cold resistance and anti-freeze compound levels in the two sexes of Pardosa astrigera, driving us to explore the differences in their intestinal microbiome. In this study, intestinal bacterial communities of P. astrigera in winter were compared using 16S rRNA high-throughput sequencing. The results showed significant differences in most alpha diversity indices and the relative abundances of dominant bacteria between males and females. Our research reveals the significant role of sex in shaping the diversity and composition of intestinal bacteria in overwintering P. astrigera. We suggest that Pseudomonas versuta (belonging to Proteobacteria) and Rhodococcus erythropolis (belonging to Actinobacteriota) may have the potential to play key roles in overwintering P. astrigera. Gut microbiota can promote the resistance of host arthropods to low-temperature stress. Female Pardosa astrigera have a lower anti-freeze compound level and weaker resistance to cold temperatures than the males in winter, which implies that their intestinal bacteria may be different during overwintering. This study primarily compared the intestinal bacterial communities between the two sexes of P. astrigera in a temperate region using 16S rRNA gene sequencing. Our findings indicated that the Chao1 and Shannon indices of intestinal bacteria in females were significantly higher than those in males, while the Simpson index in females was significantly lower than that in males. The male intestinal bacterial community was characterized by Proteobacteria and Actinobacteriota at the phylum level and by Pseudomonas and Rhodococcus at the genus level, with total relative abundances of 89.58% and 85.22%, respectively, which were also significantly higher than those in females, whose total relative abundances were 47.49% and 43.68%, respectively. In contrast, the total relative abundances of Bacteroidota and Firmicutes were significantly lower in males (4.26% and 4.75%, respectively) than in females (26.25% and 22.31%, respectively). Noteworthy divergences in bacterial communities were also found through an LEfSe analysis between females and males. Additionally, the results of the PICRUSt2 analysis showed that six out of eleven level-2 pathways related to key metabolic functions were significantly (or marginally significantly) higher in females than males, and five other level-2 pathways were significantly (or marginally significantly) lower in females than males. Our results imply that significant gender differences exist in intestinal bacterial communities of overwintering P. astrigera. We suggest that Pseudomonas versuta (belonging to Proteobacteria) and Rhodococcus erythropolis (belonging to Actinobacteriota) may have the potential to play key roles in overwintering P. astrigera. [ABSTRACT FROM AUTHOR]

Simple Summary: The study examined the phenological response of Grapholita molesta (Busck, 1916), a pest damaging Rosaceae stone fruits, to climate warming. Data on G. molesta population dynamics and climate in China from 1980 to 2020 were analyzed. Significant advancements were observed in the peak date of overwintering adults in northeastern, eastern, and northern China. Populations of contemporary adults in northwestern China and population peak date of overwintering adults in northern China also advanced. However, the end occurrence date of contemporary adults in northern China was delayed along with the first occurrence date of overwintering adults in northwestern China. The study highlighted spatial variations in G. molesta's phenological response to climate warming across China, offering valuable insights for predicting pest infestations and enhancing pest management strategies in fruit tree cultivation. Grapholita molesta (Busck, 1916), a significant pest affecting various fruits such as pears, apples, peaches, etc., is highly adaptable to changing temperatures. However, the phenological response mechanism of this pest to climate warming remains unclear. To address this issue, we collected population dynamics data of G. molesta in China over the years along with corresponding climate data. We analyzed five phenological indexes: the first, end, and peak occurrence dates of contemporary adults as well as the first and peak occurrence dates of overwintering adults in China. Results revealed an upward trend in the annual average temperature and average temperature of the four seasons in regions infested by G. molesta in eastern, northeastern, northwestern, northern, and southwestern China from 1980 to 2020. Notably, the population peak date of overwintering adults in northeastern and eastern China significantly advanced along with the first occurrence date and the population peak date of overwintering adults in northern China. Additionally, the population peak date of contemporary adults in northwestern China significantly advanced. However, the end occurrence date of contemporary adults in northern China was significantly delayed, as was the first occurrence date of overwintering adults in northwestern China. Furthermore, our study demonstrated spatial heterogeneity in the phenological response of G. molesta to climate warming across China. This study elucidates the phenological response of G. molesta to climate warming, offering valuable insights for predicting future pest infestations and informing adaptive pest management strategies in fruit tree cultivation. [ABSTRACT FROM AUTHOR]

The hibernation of amphibians can offer a unique window into overwintering adaptation processes and host–gut microbiota interactions through changes in metabolic availability and homeostasis. We attempted to identify differences in the physiology and gut microbiome during and after hibernation in Japanese wrinkled frogs (Glandirana rugosa), an aquatic overwintering amphibian. After hibernation, the high alpha and beta diversity of the gut bacterial community appears to reflect the more diverse and complex environmental conditions. During winter, Proteobacteria dominated the majority of the gut bacterial community, likely due to high oxygen saturation. After hibernation, Firmicutes and Bacteroidetes increased, which are supportive of host metabolism by gut microbiota. Corticosterone also showed high values and variances after hibernation, presumably allowing the population to remain adaptable across a broad range of environmental gradients. Innate immunity was high after hibernation but exhibited low variation among populations, which supports the idea of a prioritized investment in immunity after hibernation. Blood biochemistry suggests that aquatic overwintering frogs have a mechanism to adapt through overhydration and regulate homeostasis through water excretion associated with the kidney and urine after hibernation. Frog populations exhibit variations and adaptability in gut microbiota and physiology during and after hibernation: Through this, they may demonstrate an adaptive response that regulates metabolic availability in preparation for unpredictable environmental changes. We also propose that the maintenance of Proteobacteria during hibernation can support the colonization of Firmicutes and Bacteroidetes after hibernation, underscoring the need to study the complex effects of gut microbiota across multiple life stages. [ABSTRACT FROM AUTHOR]

During the winter, animals face limited food availability. Many animals enter dormancy to reduce their winter energy expenditure. Most insects spend the winter in diapause, a state of programmed dormancy. It is often assumed that diapausing insects need nutrient stores to fuel their many months of basal metabolism and must grow heavier than their non‐diapause‐programmed counterparts. However, the extent to which food limitation affects body weight during overwintering preparation as well as the likelihood and duration of diapause remains unclear. We limited the duration of the feeding period and thus the total quantity of food available to diapause‐destined larvae of the pupal‐diapausing flesh fly, Sarcophaga crassipalpis, to test how food limitation affects body weight in the context of diapause programming. We also tested the extent to which food deprivation and body weight affect the likelihood and duration of diapause. We hypothesized that diapause‐destined larvae grow more quickly and pupariate at a heavier body weight than non‐diapause larvae. We also hypothesized that body weight is more dramatically reduced by food limitations when a larva is programmed for diapause. Finally, we hypothesized that larvae with lighter body weight (i.e., food limited) are less likely to enter pupal diapause and also stay in diapause for a shorter duration than heavier, well‐fed, individuals. Contrary to our hypotheses that diapausing insects are heavier than their non‐diapausing counterparts, we found diapausing pupae weighed less than non‐diapausing pupae, especially when larvae received limited food. We found light pupae did not abort their diapause program. In both diapausing and non‐diapausing pupae, body weight was positively correlated with simulated winter survival. However, above a weight threshold, body weight no longer affected simulated winter survival in diapausing pupae. Contrary to our predictions and the general consensus in much of the diapause literature, we also found that lighter pupae stayed in diapause longer than heavier pupae. Overall, our results challenge the precept that body weight and diapause are positively associated. The relationship between body weight and diapause is complex and may be affected by the availability of food before and after winter, the availability of high‐quality overwintering sites, and the life history of a particular insect. [ABSTRACT FROM AUTHOR]

Bactrocera dorsalis (Hendel), a very destructive insect pest of many fruits and vegetables, is widespread in the tropical and subtropical zones of Asia. However, the northward extension of B. dorsalis has been reported in China recently. It is crucial to determine the origin of new populations and to investigate the invasive potential of the species. Here, we investigated B. dorsalis in Nanyang, Henan Province and Heze, Shandong Province using a combined methodological approach. We first detected the hydrogen stable isotope ratios (δ2H) of B. dorsalis samples. The results showed that the δ2H values for B. dorsalis from Nanyang were consistent with those of the local rainwater. In contrast, the samples from Heze were inconsistent with those of the rainwater in Heze. We then sequenced the complete mitochondrial cytochrome oxidase I (mtDNA COI) from the same fruit fly samples for haplotype diversity and phylogenetic analyses. We found a close genetic relationship between the Heze population and Nanyang, Hefei, Sanya, Fuyang and Wuhan populations. Besides, we surveyed the fruit's origin in the wholesale market, and concluded that B. dorsalis trapped in Heze might have come from Hainan and Zhejiang in China. Finally, overwintering potential experiments showed that a small number of pupae could survive during the test periods in Nanyang, whereas no pupae could survive in Heze. Overall, this study reveals that the Nanyang population of B. dorsalis were resident, whereas the Heze population did not colonize and were repeated entries from other areas every spring. [ABSTRACT FROM AUTHOR]

For non-native insects that are economically damaging, understanding the drivers of range expansions and contractions is important for forecasting pest pressure. The invasion of the redbanded stink bug, Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae), reached Louisiana, United States, in 2000, after which the northern range limits of this species have fluctuated annually. Low winter temperatures have been implicated as a major driver of this pattern, but the importance of cold temperatures—or other abiotic factors—for the persistence of this pest over large geographic scales are incompletely understood. We coupled occurrence data of P. guildinii with climatic data to investigate trends in P. guildinii presence in relation to winter temperatures and develop species distribution models, forecasting habitat suitability based on current and future climatic scenarios. Our results show that (i) some P. guildinii persisted in locations where ambient temperatures reached −12°C, (ii) overwintering temperatures drive P. guildinii range dynamics, and (iii) with intermediate projections of climatic warming, northward expansion by P. guildinii in North America is likely to be minimal. While the northern extent of P. guildinii 's range may now be largely realized in North America, our results suggest that increased frequency of mild winters could reduce interannual fluctuations of P. guildinii and enable it to become a more consistent economic concern for soybean growers throughout the Midsouth region of the United States. [ABSTRACT FROM AUTHOR]

Background: Living modified organisms (LMOs) imported into Korea may pose various risks to the domestic natural ecosystem, depending on their seed survival capacity and proliferation potential. In this study, we investigated seed germination and dormancy rates under controlled low temperatures for 12 weeks. In addition, we assessed the overwintering potential of seeds buried at 10 cm soil depth over 48 weeks using non-transgenic seeds of four major LMOs imported into Korea. Results: Brassica napus L. seeds exhibited superior germination and dormancy rates compared to Glycine max (L.) Merr., Zea mays L., and Gossypium hirsutum L. seeds when subjected to incubation at low temperatures (–5°C, –1°C, and 5°C). Seed germination was exclusively recorded for B. napus seeds in the field, which reflects the winter environment, for up to 8 weeks after burial. Seeds of both B. napus and Z. mays remained dormant in the soil for up to 4 weeks after burial; however, G. max and G. hirsutum seeds did not remain dormant. Germination rates were higher when the seeds were placed in seed bags and buried, whereas dormancy rates were higher when the seeds were buried without seed bags. Conclusions: These results suggest that B. napus could have a higher invasive potential than other plant species, which may affect its survival and spread, ultimately posing a greater threat to the ecosystem. This study provides valuable insights into the immediate need for establishing risk assessments and safety management measures for LMOs (specifically B. napus).

IntroductionWarming summer temperatures have the potential to harm managed pollinators, impacting both summer performance and overwintering success. The alfalfa leafcutting bee, Megachile rotundata, is a solitary bee used for commercial pollination of alfalfa. M. rotundata undergoes facultative diapause in the prepupal stage. Prepupae that diapause early in the season are exposed to warm temperatures for a longer period of time than the individuals that start diapause closer to fall, which may reduce lipid reserves required for overwintering survival. Warm temperatures may also contribute to pollen ball incidence, which is when a provision is present but there is no sign of a larva in the brood cell. Our goal was to identify factors that regulate diapause and pollen ball incidence and examine effects of pre-wintering field conditions on post-overwintering energy reserves in M. rotundata.MethodsNest boxes were installed near Fargo, ND, Laramie, WY, and Las Cruces, NM, which exposed bees to different photoperiods and thermal regimes. Three nest boxes were placed at each site. We monitored nesting conditions and diapause and pollen ball incidence throughout the season. Lipids, sugars, and glycogen reserves were measured in adults after overwintering.Results and DiscussionOur models indicate that most of the variation in diapause incidence was explained by nest, with individuals within a nest tending to have the same diapause outcome. This suggests that the environmental conditions experienced by the mother, or genetic predisposition, influences offspring diapause. We also found evidence that high cavity temperatures can cause diapause aversion. In addition, our study is the first to link high nesting cavity temperatures to increased pollen ball incidence. Exposure to stressful temperatures during development and early diapause resulted in an increase in adult lipid reserves after overwintering. Adult sugar and glycogen reserves were not affected by exposure to warm temperatures during development and early diapause. In conclusion, maternal effects and temperature were important factors for diapause and pollen ball incidence in M. rotundata with macronutrient reserves similar for early and late season bees.

We tested the expression of the multi-functional gene Vitellogenin (Vg) in four commercially available stocks of honey bees (Apis mellifera: L) under three different treatments: caged bees fed only 50% sucrose solution, caged bees fed sucrose solution and pollen paste, and free-roaming bees in a colony setting. We found that seven-day old bees fed pollen and sucrose in the lab as well as those in the colony had higher Vg expression than those fed only sucrose. There were strong differences in how the stocks responded to the treatments. This ranged from the Italian bees where expression was different between all treatment groups to the Saskatraz where there were no effects of treatment on Vg expression. [ABSTRACT FROM AUTHOR]

Abstract The biogeographical range shift of insect pests is primarily governed by temperature. However, the range shift of seasonal long-distance migratory insects may be very different from that of sedentary insects. Nilaparvata lugens (BPH), a serious rice pest, can only overwinter in tropical-to-subtropical regions, and some populations migrate seasonally to temperate zones with the aid of low-level jet stream air currents. This study utilized the CLIMEX model to project the overwintering area under the climate change scenarios of RCP2.6 and RCP8.5, both in 2030s and 2080s. The overwintering boundary is predicted to expand poleward and new overwintering areas are predicted in the mid-latitude regions of central-to-eastern China and mid-to-southern Australia. With climate change, the habitable areas remained similar, but suitability decreased substantially, especially in the near-equatorial regions, owing to increasing heat stress. The range shift is similar between RCP2.6-2030s, RCP2.6-2080s, and RCP8.5-2030s, but extreme changes are projected under RCP8.5-2080s with marginal areas increasing from 27.2 to 38.8% and very favorable areas dropping from 27.5 to 3.6% compared to the current climate. These findings indicate that climate change will drive range shifts in BPH and alter regional risks differently. Therefore, international monitoring programs are needed to effectively manage these emerging challenges.

In Nunavik, anadromous Arctic char spend more than 6 months under ice-covered habitats, mainly in lakes. Their winter habitats in this region have been scarcely studied due to the challenging logistics in the Arctic. In this study, we worked with Inuit fishers to characterize the winter habitat and incubation areas used by Arctic chars in five overwintering lakes and one lentic river reach. The collaborating fishers determined char occupancy of certain areas related to fishing sites (presence, absence, and spawning) and conducted measurements to characterize the sites while performing their fishing activities. The data showed that incubation areas were associated with significantly shallower depths and warmer (albeit not statistically significant) lake bottom temperatures than sites where no spawning occurs, which is beneficial for egg maturation. The productivity of these areas is also beneficial for fry that hatch during winter. Adult and post-smolt habitats tended to be associated with cold littoral zone, but their habitat did not show any other distinct characteristics. This exploratory study adds insights into the cryptic characteristics of the Arctic char winter habitat use, thanks to the Inuit fishers’ knowledge of fish habitats and movements, and the experience and expertise they have acquired working in the local environment.

The biogeographical range shift of insect pests is primarily governed by temperature. However, the range shift of seasonal long-distance migratory insects may be very different from that of sedentary insects. Nilaparvata lugens (BPH), a serious rice pest, can only overwinter in tropical-to-subtropical regions, and some populations migrate seasonally to temperate zones with the aid of low-level jet stream air currents. This study utilized the CLIMEX model to project the overwintering area under the climate change scenarios of RCP2.6 and RCP8.5, both in 2030s and 2080s. The overwintering boundary is predicted to expand poleward and new overwintering areas are predicted in the mid-latitude regions of central-to-eastern China and mid-to-southern Australia. With climate change, the habitable areas remained similar, but suitability decreased substantially, especially in the near-equatorial regions, owing to increasing heat stress. The range shift is similar between RCP2.6-2030s, RCP2.6-2080s, and RCP8.5-2030s, but extreme changes are projected under RCP8.5-2080s with marginal areas increasing from 27.2 to 38.8% and very favorable areas dropping from 27.5 to 3.6% compared to the current climate. These findings indicate that climate change will drive range shifts in BPH and alter regional risks differently. Therefore, international monitoring programs are needed to effectively manage these emerging challenges. [ABSTRACT FROM AUTHOR]

The common eastern bumble bee (Bombus impatiens) queens endure cold winter months by entering a diapause state. During this overwintering period, these animals use stored energy reserves while maintaining a low metabolic rate. This study investigates changes in the metabolic rate of bumble bee queens during diapause-like laboratory conditions and the potential reorganization of the flight muscle metabolic properties during this period. We first confirmed the hypometabolic state of queens during diapause in the laboratory, which lowered their resting metabolic rate to less than 5% of normal resting values. Body mass decreased during diapause, body composition changed where carbohydrates decreased initially, and later protein declined, with a similar trend for lipid content. Using cellular respirometry, we determined the capacity of the flight muscle cells of bumble bee queens to use various metabolic fuels and whether this capacity changes during the progression of diapause to favor stored lipid-derived substrates. Queens showed a low capacity to oxidize the amino acid proline, compared with workers, and their capacity to oxidize all metabolic substrates did not change during a 4-mo diapause period in the laboratory. We also show no detectable ability to oxidize fatty acid by flight muscle mitochondria in this species. The metabolic properties of flight muscle tissue were further characterized using metabolic enzyme activity profiles showing little change during diapause, indicating that profound metabolic suppression is induced without major changes in muscle metabolic phenotypes. Overall, B. impatiens queens undergo diapause while maintaining flight muscle capacity under the conditions used. [ABSTRACT FROM AUTHOR]

Cold winter temperatures govern the distribution and abundance of many insect species, but refugia that provide microclimates can moderate temperature-driven mortality. Winter temperatures have been implicated in limiting the survival and range of Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae; redbanded stink bug), an economically damaging invasive pest in the southeastern United States, but the role of refugia in overwintering survival of this pest is poorly understood. We conducted 2 studies in successive years to evaluate how leaf litter from hardwoods, pines, and soybeans modulate overwintering site selection and survival of P. guildinii. In the second-year study, we also quantified the buffering effect of the 3 leaf litter types compared to ambient conditions and assessed diapause. In the first-year study, we found that stink bugs preferentially dispersed into leaf litter compared with remaining unsheltered on bare soil; no clear preference among leaf litter types was found. In the second year, however, no clear differences were found among leaf litter types and bare soil. Means of daily minimum temperatures under leaf litter were at least 3.0 ± 0.9 °C (SE) warmer and generally less variable than ambient conditions. While high mortality in both studies illustrates that more work must be done to fully understand overwintering survival, limited survival through potentially lethal conditions in the first-year study nonetheless emphasizes the possibility of populations persisting and rebounding in the following spring. Furthermore, our study highlights the potential for stink bugs to persist in areas with lethal ambient temperatures by dispersing into widely available substrates. [ABSTRACT FROM AUTHOR]

We investigated the lower thermal limits of Anagyrus vladimiri Triapitsyn (Hymenoptera: Encyrtidae), a natural enemy of mealybugs. Parasitoids were cooled to measure supercooling points and the lower lethal temperature LLT50. To investigate survival after long-term cold exposure, parasitoid adults and eggs, larvae, and pupae within their host mummy were gradually acclimated. Adults were then exposed for three days to 7 °C, 5 °C, 3 °C, and 1 °C, and immatures for varying durations to 5, 1, and − 4 °C. Parasitoids were investigated for survival and reproduction. To assess the impact of fluctuating temperature, parasitoid pupae were subjected to daily warming to 10 °C from baseline temperatures of 5 °C, 1 °C, and − 4 °C during four-day-cold exposure. Finally, eggs, pupae and adults were exposed to winter conditions in Switzerland in a semi-field setup. The LLT50 was − 17.24 °C for adults and 0.94 °C for pupae. Both values were above the supercooling points. No adult survived three days at 3 °C and lower. Likewise, no emergence occurred from eggs or larvae exposed for four days and longer to 1 °C or seven days to 5 °C. Pupae were cold-hardier surviving seven days at 5 °C and three days at 1 °C. Parasitoids surviving cold exposure were still able to reproduce. Daily warming decreased emergence of cold exposed pupae at a baseline temperature of 1 °C but not at 5 °C and − 4 °C. No eggs, pupae and adults survived winter conditions in the semi-field experiment. We thus consider A. vladimiri a chill-susceptible species with very limited cold-tolerance of the investigated population and low chances of survival during winter in Northern Switzerland. [ABSTRACT FROM AUTHOR]

【Objective】To clarify potato blackleg disease source of infection in Ulanqab City,Inner Mongolia,and provide the basis for formulating effective prevention and control measures for potato blackleg disease.【Methods】The pathogen isolation,pathogenicity identification,molecular identification and soil survival tests of potato blackleg disease were carried out. Through pot experiment and field experiment,seven treatments were set up to investigate the occurrence of potato blackleg disease in the soil of continuous cropping land,seed potatoes of diseased land and diseased residues,and analyze and verify the differences in incidence rate of different treatments.【Results】The incidence rate of potato blackleg harvested in diseased areas and planted as seed potato over winter was 40.00%. Pectobacterium atrosepticum was isolated from the disease residue buried in soil after overwintering,and the incidence rate was 43.33% in the experiment of planting disease-free potato after the disease residue was planted in the disease-free soil. The incidence rate of disease-free potato was 6.67% in the previous diseased plots. The amount of pathogenic bacteria in unsterilized soil gradually decreased with the extension of time,and no longer survived after two months at normal temperature,and no longer survived after four months at -20 ℃. The results indicated that P. atrosepticum could survive the winter in the disease residual and become the primary infection source in the second year. The pathogenic bacteria in diseased soil were related to the occurrence of disease,but the bacteria free in cultivated soil could only survive for two months at natural temperature.【Conclusion】 The primary infection source of potato blackleg disease in Ulanqab City,Inner Mongolia is the infected seed potato and the disease residual after winter,and the amount of bacteria carried by the seed potato is an important factor affecting the occurrence of the disease. [ABSTRACT FROM AUTHOR]

The native green apple aphid (Aphis pomi DeGeer) and the invasive green spirea aphid (Aphis spiraecola Patch) share apple as a common host plant during the summer months in Central Europe. Various studies suggest that, under certain conditions, the originally host-alternating A. spiraecola is able to overwinter on apple as a winter host, following a similar life history to A. pomi. In this study, we collected stem mothers (fundatrices) and aphids of the second generation (fundatrigeniae) from ten localities throughout Hungary for nine consecutive springs to assess whether A. spiraecola can overwinter on apple as a winter host. All the collected aphid individuals (1126 aphids from 114 stem colonies during the nine years of the study) belonged to A. pomi, indicating that A. spiraecola does not, or very rarely can, overwinter on apple under Central European conditions. [ABSTRACT FROM AUTHOR]

Abstract Frozen water bodies provide a physiological challenge to fauna by physically limiting access to atmospheric oxygen. To tolerate low temperatures, reptiles use brumation as a physiological strategy in winter. Cryptodira vary in their tolerance to freezing conditions but the extent of tolerance in pleurodirans is largely unknown. Australia's freshwater turtles inhabit warmer regions with less severe winters and have well‐developed mechanisms to cope with high temperatures and drying waterbodies, rather than extreme cold tolerance. Chelodina longicollis is a widespread Australian freshwater turtle species that tolerates high temperatures and desiccation during hot, dry periods while also undergoing brumation during winter months. Despite extensive research, limited observations exist on their behaviour during severe winter periods at the extremes of their range. In an 11‐month tracking study, we monitored adult C. longicollis, noting their movements, locations, and temperature weekly. We observed an adult female C. longicollis which, during a seven‐month period within a single creek pool, survived brumation in extreme cold water including a 15‐day period of total freezing of the surface water. After the ice melted following a rain event, the turtle was recaptured alive. This marks the first observation of brumation for an Australian chelid species under ice.

Western Monarch butterflies (Danaus plexippus) migrate from inland breeding ranges to coastal overwintering grounds in California. Given that migratory individuals may make multi-scale habitat selection decisions, we considered a multi-scale species distribution model (SDM) using range-wide climatic and local landscape-level predictors of migratory and overwintering habitat and community-science presence data. The range-wide model output was included as a predictor in the local-scale model, generating multi-scale habitat suitability. The top range-wide predictor was the minimum temperature in December, contributing 83.7% to the model, and was positively associated with presence. At the local scale, the strongest predictors of presence were the range-wide output and percent coverage of low and medium levels of development, contributing > 95%, with 61–63% from the range-wide output, with local-scale suitability coinciding with the California coastal zones. Development’s positive association with overwintering monarch presence was counterintuitive. It is likely that our local-scale model is overfit to these development zones, but it is unclear whether this overfitting resulted from modeler choices, monarchs overwintering close to human development, biased detection near human development, or a combination of these factors. Therefore, alternative approaches to collecting local-scale attribute data are suggested while recognizing the primacy of climate in restricting overwinter sites.

It is widely recognized that the phenology of insects, of which the life activities are closely tied to temperature, is shifting in response to global climate warming. This study aimed to investigate the impacts of climate change on the phenology of Carposina sasakii Matsumura, 1900 (Lepidoptera: Carposinidae) across large temporal and spatial scales, through collecting and systematically analyzing historical data on the pest’s occurrence and population dynamics in China. The results showed that for overwintering adults, the first occurrence date in eastern, northwestern, and northern China has significantly advanced, along with the population peak in eastern and northwestern China. At the provincial level, the population peak date in Shandong province has also moved significantly earlier, as well as the population peak date in Shandong and Shaanxi and the end occurrence date in Ningxia. However, the population peak date in Jilin has experienced a delayed trend. For first-generation adults, the first occurrence date in northeastern, eastern, and central China has notably advanced, while the first appearance date in northwestern and northern China has significantly delayed. Additionally, the population peak in northwestern China has experienced significant delays, along with the final occurrence in northeastern and northwestern China. At the provincial level, the first occurrence date in Liaoning, Shandong, and Shanxi has significantly advanced, while Hebei has demonstrated a significant delay. The population peak time in Gansu and Shaanxi has displayed significant delays, and the end occurrence date in Liaoning, Shanxi, and Shaanxi has also shown significant delays. Furthermore, these findings integrated with the Pearson correlation results reveal spatial heterogeneity in C. sasakii’s phenological responses to climate warming at both regional and provincial scales. The phenology of C. sasakii and their changing patterns with climate warming vary by geographical location. This study provides valuable information for the future monitoring, prediction, and prevention of peach fruit moths in the context of climate warming.

Temperature is among the key factors impacting the establishment and spread of invasive pests. The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the major pests attacking Solanaceae plants and is known to possess overwintering capacities. However, the cold hardiness of T. absoluta pupae is poorly documented. In this study, we investigated the effect of constant temperature and stepwise cooling on T. absoluta pupae under laboratory conditions. For this purpose, bioassays on pupal development under constant temperature (5°C) for 30, 60 and 90 days, and stepwise changes in temperature (11, 10 and 8°C; in this order every 30 days), were assessed. We found that exposure to 5°C for 30 and 60 days did not affect the post-cooling emergence time of adults compared to the control. Pupae completed their development after 60 days of cold exposure at 5°C, but more adults emerged after 30 than 60 days. Even though alive pupae were observed after 90 days of cold exposure at 5°C, no adults emerged. External colours of pupae depended on the duration of cold periods, and green pupae obtained after 30 and 60 days were found to be positively correlated with the emergence of adults. When pupae were kept at 11°C for 30 days, 47% emerged, and when the temperature was changed to 10, only 12% of pupae emerged for the period 31–60 days. However, the decrease of the temperature to 8°C yielded no emergence for the period 61–90 days. Our study provides useful information to better understand the population dynamics of overwintering T. absoluta , and to underpin the development of monitoring and control strategies for the pest. [ABSTRACT FROM AUTHOR]

Mass mortality events appear to be increasing in intensity and frequency, so understanding their causes and consequences is imperative for wildlife conservation. We report on a mass mortality event in a population of Northern Map Turtles (Graptemys geographica (LeSueur, 1817)). At a communal overwintering site, 142 carcasses (ca. 10% of population) were recovered, seemingly depredated by river otters (Lontra canadensis (Schreber, 1777)). We compared the size and sex of the carcasses to those of turtles that survived. Smaller turtles and males were more likely to be depredated than larger turtles and females. Using captures made at the same overwintering site between 2003 and 2022, we assessed the vulnerability of this population to mass mortality events during winter. Nearly 60% of the 1875 turtles marked between 2003 and 2022 used the overwintering site where the mass mortality event occurred at least once. On average, turtles overwintered at the site at least 38% of the winters between their first and last capture. Our study shows how behaviour and physiology interact to predispose a species to mass mortality events and ecological traps. Protecting overwintering sites and minimizing human pressures affecting winter depredation may be essential for the preservation of certain turtle populations. [ABSTRACT FROM AUTHOR]