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The germinability of buried seeds changes with time, and the direction and periodicity of these changes differ among plant species. In 116 abundant dicotyledonous herb species, we investigated the changes in seed germinability that occurred during the 2-yr period following burial in the soil. We aimed to establish differences between seeds collected in “anthropogenic” (ruderal, arable land) and “wild” (grassland, forest) habitats. The seeds were buried in a field 1 mo after collection, exhumed at regular intervals, and germinated at 25 C. During the 2-yr study period, four categories of species-specific patterns of germinability changes were found: seeds demonstrating seasonal dormancy/nondormancy cycles (31 species); seeds germinating only in the first season after burial (16 species); seeds germinating steadily (38 species); and seeds whose germinability changed gradually, with increasing (7 species) or decreasing (18 species) germinability. The seeds of 6 species did not germinate at all. We found no significant difference in the frequency of these categories between species typical for anthropogenic and wild habitats. The cause for this result may be dramatic human influences (changes of agricultural practices), the pressure of which impedes the development of floras specific for certain habitats, as distinguished by the frequency of species with particular patterns of seed germinability. These frequencies varied among taxa with the growth form, seed mass, and flowering phenology of species.

In central Europe, barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], has commonly been found in humid lowland areas. As a result of the introduction of new crops and farming practices, in the northwest Carpathians, E. crus-galli has spread from lowland (400 m altitude) areas. We collected seed samples from local populations lying at a distance of approximately 5 km from each other and lined up along transects following the flows of two rivers. The rivers first flow through the valleys separated by mountain ridges and eventually flow into a common lowland. After ripening, the seeds of all populations were germinated at 25 C under long-day conditions. Only the seeds of some lowland populations germinated up to 75%. The frequency of germinated seeds decreased as the altitude where the population was collected increased, and above 200 m above sea level, germination was mostly zero. We then studied the phenological and morphological differentiation of plants from the original (lowland) and recently occupied (highland) areas. Seeds of the lowest and the highest localities lying on the transect of each river were sown in a common garden experiment. In plants from the highland localities, heading and seed dispersal were earlier, while tiller height and tiller mass were lower than in plants from the lowland localities. Seed mass produced per tiller in the lowland and highland plants was similar, and as a result, highland plants allocated a larger proportion of body mass to seed production than did lowland plants. Echinochloa crus-galli populations from highland localities thus produce their progeny earlier and at a lower energy cost than populations from lowland localities. The plasticity of phenological characters likely facilitated adaptation during E. crus-galli spread from lowlands to highlands. Similar adaptations in plant phenology may contribute to the spread of E. crus-galli in other geographic areas.

The current climate warming is associated with the development of a second generation in populations of species such as Pyrrhocoris apterus (L.) (Heteroptera: Pyrrhocoridae), which, in Central Europe, were univoltine in the 1980s. Females of the first generation that develop in spring either enter diapause immediately following the adult moult or after a period of oviposition that gives rise to a second generation. In 2005-2010, in overwintering populations, 3 ± 0.6% of females were fertilized. We explored the possibility that the females that overwintered in a fertilized state were those that had oviposited in the previous season. To test this hypothesis, we reared females of the first generation that moulted to the adult stage in June-August under natural conditions. For these females, we recorded oviposition, mortality and overwintering in the fertilized state. In 2004-2007, the majority (78%) of the first-generation females that oviposited in summer also died before winter and the rest entered dormancy and overwintered. Most of the overwintering females that had laid eggs before overwintering were fertilized. However, the majority (63%) of females that overwintered in the fertilized state had not laid eggs in the previous season; they only copulated and stored the sperm until the next spring. The presence of fertilized females in a hibernating population thus indicates pre-winter sexual activity but not the percentage of first-generation females that oviposit before overwintering.

The population density of Eucallipterus tiliae (L.) (Hemiptera: Aphididae) required for initiating oviposition in Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) was established in Tilia cordata Mill. (Dicotyledoneae: Tiliaceae) stands sampled weekly throughout the vegetative seasons of 2017–2019. The number of aphids per leaf area and oviposition in H. axyridis females were determined at each sampling session. Seasonal changes in aphid abundance and the presence of ovipositing females in natural populations varied across years but in all years H. axyridis started oviposition as soon as the aphid density increased above 10.2 aphids per ten sweeps, which equals 1.04 aphids per 100 cm2 leaf area. These values exceed the threshold aphid density for starting oviposition in Coccinella septempunctata L. (Coleoptera: Coccinellidae), which is 0.40 aphids per 100 cm2 leaf area. This difference is in line with H. axyridis preference for trees, host plants with complex architecture and hard to search, and preference of C. septempunctata for spatially simple herbs.

Wildlife observations submitted by volunteers through citizen science initiatives are increasingly used within research and policy. Ladybirds are popular and charismatic insects, with most species being relatively easy to identify from photographs. Therefore, they are considered an appropriate taxonomic group for engaging people through citizen science initiatives to contribute long-term and large-scale datasets for use in many different contexts. Building on the strengths of a mass participation citizen science survey on ladybirds in the United Kingdom, we have developed a mobile application for ladybird recording and identification across Europe. The main aims of the application are to: (1) compile distribution data for ladybird species throughout Europe, and use this to assess changes in distribution over time; (2) connect and engage people in nature and increase awareness about the diversity and ecological importance of ladybirds. In developing the application we first constructed a database including ladybird species from the United Kingdom, Czech Republic, Slovakia, Italy, Belgium, and Portugal with associated information on relevant morphological features (e.g., size, main color, pronotum pattern) to inform identification. Additionally, the species were assessed on the basis of probability of occurrence within each country which enables users to reduce the number of species to only those with relevance to the location of the recorder. This is amongst the first collaborative citizen science approaches aimed at involving participants across Europe in recording a group of insects. In the near future, we aim to expand the use of the application to all countries in Europe. AOS was supported by FEDER in 85% and by Azorean Public funds by 15% through Operational Program Azores 2020, under the following project AZORESBIOPORTAL -PORBIOTA (ACORES-01-0145FEDER-000072). Further funding for app development was provided by Anglia Ruskin University. info:eu-repo/semantics/publishedVersion

The mating behaviour of Pyrrhocoris apterus in the laboratory is well studied, but little is known about it under natural conditions. In natural populations in Central Europe, overwintered adults start copulating in March and continue until their death. Caged females, kept under natural conditions in the permanent presence of males, copulated repeatedly. Their mating activity increased sharply until early April, then very slowly until the end of June and then declined as the females die-off. Half of copulations were short (< 5 h) and only 9% were longer than 1 day. By contrast, in natural populations, mating activity (percentage of individuals involved in copula) reached its maximum in April and then decreased until early July, when the overwintered adults die. The decline in mating frequency (percentage of adults involved in copula) was associated with a decrease in the availability of receptive females towards the end of the mating period. For a female, repeated copulation is necessary because sperm is nearly depleted after insemination of 3-5 egg batches.

Seeds of many species of plants may survive for a long time in the soil and germinate when brought to the surface, but whether they are subsequently eaten by seed predators is unknown. We examined the preferences of three species of carabids (Coleoptera: Carabidae) for 25 species of seeds and determined the difference in palatability between freshly dispersed and those buried for six years. The stability of their preferences was tested using a collection of seeds of different species, each of which was offered fresh or after being buried. Carabid beetles readily accepted previously buried seeds as food. In total, Pseudoophonus rufipes and Amara littorea ate more fresh seeds than previously buried seeds, while the opposite was true for Harpalus affinis. The seeds of some species were even more attractive to carabids after burial than in the fresh state. For all the species of carabids tested, the diet breadth was similar when the beetles were fed fresh or buried seeds, but the preferences for fresh and buried seed of particular species were correlated only in P. rufipes and A. littorea. We measured the seed characteristics (mass and viability) likely to be associated with the loss of attractiveness to carabids during burial. The change in carabid consumption was not related to changes in any of these characteristics. This finding indicates that factors responsible for variation in seed acceptability are complex. This study provides the first conclusive evidence that invertebrate seed predators will feed on seeds from seed banks, although they prefer fresh seeds.

In 2016–2019, seasonal changes in the abundance of the harlequin ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) were established in the city center of Prague, Central Europe, and in its outskirts. Adults were sampled from lime trees (Tilia spp.) at regular intervals throughout the growing season. The abundance of H. axyridis paralleled the course of abundance of its prey, the aphid Eucallipterus tiliae L., which peaks either early or late in the season. As a result, the seasonal dynamics of H. axyridis were unimodal, with a peak in the early (late June—early July of 2017 and 2019) or late (late July—mid-September of 2016 and 2018) period of the season. In the early period, there was a small (1–4 days) difference in the timing of the peak of H. axyridis between the city center and the outskirts. In the late period, the peak occurred significantly earlier (by 13–21 days) in the city center due to the warmer climate there than in the outskirts. The difference in the timing of the population peak between both locations disappeared after recalculating the calendar to thermal time (number of day degrees above 10.6°C thresholds elapsed from the end of H. axyridis hibernation). The warm mesoclimate of the city center advances the seasonal dynamics of H. axyridis, contributing to the success of this invasive species in urban habitats.

The box tree moth Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) is an invasive species in Europe and a serious pest of box trees (Buxus spp.). In Slovakia, Central Europe, it was first reported in 2012 within the low elevation region with a warm climate. We hypothesize that the cold mountain region of Slovakia would provide less suitable conditions for the spread of this species, indicated by no or only slight damage to box trees. Five years after C. perspectalis was first recorded in Slovakia, we assessed the probability of occurrence of the moth and the probability of damage to box trees (Buxus sempervirens) by its larvae, using temperature and altitude data as predictors. In June and July 2017, at 156 locations (towns and villages) between the altitudes of 109 and 888 m, we recorded damage and categorized the intensity of damage to box trees by C. perspectalis using a four-point scale. Box trees infested by C. perspectalis were recorded in most locations at altitudes between 110 and 400 m with the mean annual temperature varying between 10.5 and 7.9 &deg, C. High damage to box trees was found in locations up to 340 m a.s.l. characterized by mean annual temperatures above 8.5 &deg, C. Our results suggested high probability (&gt, 60%) of any damage to box trees for the area up to approximately 300 m a.s.l. (mean annual temperature above 8.4 &deg, C), and high probability (&gt, 60%) of high damage for the area up to approximately 250 m a.s.l. (mean annual temperature above 9 &deg, C). The area where damage to box trees was predicted using the altitude showed great overlap with the area predicted using the mean annual temperature. The area with the probability of any damage was only slightly larger than the area with the probability of high damage.

The factors that affect the local distribution of the invasive Harmonia axyridis are not yet completely resolved. Hypotheses predicting positive and independent effects of prey abundance and degree of urbanization on the adult abundance of this species in Central Europe were tested. Populations of H. axyridis were sampled in a period when it was most abundant, by sweeping lime trees (Tilia spp.) at 28 sites along a 20 km transect across urban (western Prague) and surrounding rural areas. The sites differed in aphid abundance (number of Eucallipterus tiliae per 100 sweeps) and degree of urbanization (percentage of the surrounding area within a 500 m radius covered by impervious human constructions). Multiple linear regression analysis of log-transformed data revealed that abundance of H. axyridis (number of adults per 100 sweeps) increased significantly with both aphid abundance (P = 0.015) and urbanization (P = 0.045). The positive relationship between degree of urbanization and abundance of H. axyridis was thus not a side effect of variation in aphid abundance, which was also greater in urban than rural areas. The effect of urbanization might constrict the habitat available to H. axyridis and force this species to aggregate in urban green "refugia". These results point to a plurality of factors that determine coccinellid abundance at natural sites.

In Central Europe, the most abundant aphid infesting the leaves of small grain cereals is Metopolophium dirhodum (Walker) (Homoptera: Aphididae). Annual variation in its seasonal dynamics was evaluated using a 25-yr series of standardized weekly censuses of winter wheat plots. M. dirhodum made up >50 % of the aphids on the foliage. Date of immigration (8 May–3 July), length of period of population increase (0–9 wk), and date of attaining maximum abundance (28 May–22 July) varied greatly. For the prediction, we regressed maximum numbers/tiller on numbers recorded in the first week after heading. The regression of maximum abundance on nonzero aphid counts revealed a critical number of ≥1.50 aphids/tiller, which if exceeded resulted in a harmful maximum abundance of ≥10 aphids/tiller at the peak. Zero aphid counts resulted in 10% of cases with a harmful maximum abundance. Using this regression for prediction will result in 18% of the recorded cases being false negatives and 9% false positives. Parallel annual variation in the average maximum numbers of M. dirhodum, Sitobion avenae (Fabricius) (Homoptera: Aphididae), and Rhopalosiphum padi (Linné) (Homoptera: Aphididae) indicated the following factors that affected their abundance: temperature in winter and host plant quality. The predictions apply only in areas where M. dirhodum is holocyclic and aphids do not overwinter in wheat stands.

Production of feces (PF) is a useful proxy indicating quantity of ingested food. Although influenced by many uncontrolled factors PF provides insight into food consumption under natural conditions. In Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) variation in PF was investigated in populations of various hostplants at localities of central Bohemia (50N, 14E), throughout the season of 2016. The adults collected from these hostplants were starved for 48 h at standard conditions, and dry mass of feces produced during this period was measured. Despite enormous differences in PF among individuals, significant variation over the season occurred in average PF of both males and females. PF increased with abundance of aphids and was significantly greater in females than males. Gravidity, as manifested through oviposition within 48 h after capture, was associated with increased PF, while hostplant and color morph did not affect variation in PF among individuals. From PF as measured in this study, it can be estimated that at sites hosting abundant aphid populations H. axyridis (as an adult male or female) may consume 19 (male) to 45 (female) aphids per day (assumed body length 1mm). In the absence of aphids, adults may consume one to nine individuals of alternative prey per day (body length 1-2 mm).

Seed heteromorphism is a marked character of many Chenopodioideae (Amaranthaceae). Seed morphs differ in dormancy, germination and seedling biology, but differences in their predation have not yet been studied. Atriplex sagittata produces small black dormant and large brown non-dormant seeds. In this study, the timing of seed release and seedling establishment were ascertained, and their consumption by invertebrates (carabids, isopods and slugs) was studied. Seeds dispersed in the autumn passed the winter on the ground surface, protected from invertebrate predation by low temperatures. In the following vegetative season, ungerminated black seeds exposed to predation on ground surface were preferred by a large carabid species, Pseudoophonus rufipes. Some black and all brown seeds escaped predation by germinating in early spring. The seedlings were little endangered by carabids and isopods but were preferred by an invasive slug, Arion vulgaris, the feeding of which can exterminate seedlings at places in which slugs are abundant. Invertebrate predation is important factor of seed and seedling mortality of A. sagittata and seed heteromorphism modifies its intensity and timing.

Seeds in soil banks can survive for many years before conditions become more suitable for germination. Meanwhile, seeds undergo changes in morphology and viability. In this study, we launched an artificial seed bank experiment that included 26 species of seeds. We excavated cohorts for 6&ndash, 8 consecutive years after burial (YAB) in order to determine changes in the morphology (mass, volume, density, seed form) and proportion of fresh (thus persistent) seeds using a crush test as a measure of persistence. The change in seed morphology was fitted by linear and logistic regression, and the proportion of persistent seeds was fitted by logistic regression (effectively by the binomial GLM), which enabled estimation of 50 and 5% persistence times (PT50 and PT05). We found that in most species, seed mass, volume and proportion of persistent seeds declined with YAB, while other morphological traits were less variable, and the decline in these traits with YAB was best fitted with logistic regression. The decline in the proportion of persistent seeds was better fitted by the change in mass than by YAB in some species. Among the species included in this study, PT50 ranged from 1.2 to 10.5 years, and PT05 ranged from 2.1 to 24.3 years. These results can contribute to better understanding of the ecology of weed seed bank persistence in soil. Describing the morphological changes that the seeds undergo in the soil bank may improve our understanding of the biology of seed persistence and facilitate the identification of seeds from the soil bank.

The Harlequin ladybird Harmonia axyridis Pallas, native to eastern Asia, is an invasive, non-native species that has recently achieved an almost worldwide distribution. A conspicuous feature of this species is colour polymorphism of the elytra. In its native area, the populations consist of a recessive non-melanic morph, several dominant melanic morphs and small numbers of other (rare) morphs. The morph proportions in native populations have been intensively studied and vary with geographic area, climate and time. In contrast, colour polymorphism in invaded regions has been little studied. We examine and try to account for the morph frequencies observed across the different invaded regions. In America, monomorphic populations consist of the non-melanic morphs while European populations contain also melanic morphs. In particular geographic areas of Europe, the average percentage of the non-melanic morphs varied between 78 and 99%. It was highest in the lowlands of northern Italy and central and northern Europe and decreased in the Alps and western (Spain, UK) and eastern (southeast Russia) margins of the recently invaded area. In central Europe the frequency of the non-melanic morphs decreased over the course of the year but increased over the years from 2010 to 2018. The local differences might thus arise through gradual change of the morph composition of the founder invasive, non-native population. However, the variation in non-melanic morph frequency was not correlated with climatic characteristics that might affect coccinellid polymorphism. The observed rate of change in morph proportions in our data was too small to explain the diversification of what was supposedly a uniform invasive, non-native population at the point of introduction.

Post-diapause, overwintered adults of the true bug Pyrrhocoris apterus L. (Heteroptera, Pyrrhocoridae) form conspicuous aggregations at warm spots in early spring. Using a combination of laboratory experiments and field observations, we assessed the influence of this behaviour on the seasonal timing of reproduction. In the laboratory, post-diapause pairs mated after an accumulation of 80° days (dd), and females started to lay eggs after an additional 80 dd (considering 10.3 °C as a lower temperature threshold for post-diapause development). In the field, however, females mated as early as late March (based on data from four seasons), which corresponded to the accumulation of15 dd (based on summing the temperatures recorded at a meteorology station). Such a 'discrepancy' between laboratory and field data is explained by thermoregulation. Aggregated adults bask in sunny spots, thereby increasing their body temperatures to ~25 °C, which is 7-16 °C above the temperature of the surrounding ground. This thermal excess speeds up their post-diapause development and enables early mating and oviposition. As a result, behavioural thermoregulation hastens the seasonal start of reproduction in P. apterus by 1 month.

We evaluated the status of native ladybird assemblages in the presence of the non-native ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) in three European countries. To achieve this, we assessed the abundance of ladybirds from common host plants in urban areas of Great Britain, Czech Republic and Slovak Republic in 2014. We determined (i) the effects of season, host plant, location, abundance of H. axyridis and aphids on the ladybird species assemblage, (ii) the relationship between ladybird abundance and aphid density, (iii) the relationship between diversity of native ladybird species and the abundance of H. axyridis. There was a non-linear relationship between abundance of ladybirds and abundance of aphids but we found the abundance of other ladybird species was not correlated with H. axyridis. We highlight the value of large-spatial scale studies for revealing patterns in community assemblages and ultimately informing understanding of ecosystem resilience.

To understand the role of native ladybird biodiversity in habitat susceptibility on the establishment and spread of Harmonia axyridis Pallas (Coleoptera: Coccinellidae), we characterized and compared European communities where they had established and where they had not established. The local communities of ladybirds were characterized in terms of biodiversity, the average difference in body mass between H. axyridis and other coccinellid species and the rarefied total body mass of all individuals (as a surrogate for aphid abundance and availability). The lack of success of H. axyridis in the Azores, as well as its low success in Southern Europe, can be explained by a combination of resource availability and intraguild competition. We suggest the success of this invasive alien species to establish in a habitat depends first on resource availability and second when most direct competitors for limited resources are absent or are uncommon.

A new species invading a new area may cause a decrease in diversity of the community already present there. Comparison of temporal changes in species diversity of the “new” community (including alien species) with those of the “original” community (including only native species) may clarify our understanding of the effect of alien species. Using a simulation-based modelling approach we considered several scenarios describing the invasion of native communities by alien species and calculated the trends in Shannon-Wiener indices and in the numbers of species of the “original” and “new” communities during the course of the invasion. We found that despite a large increase in the population size of the invasive alien species the diversity of the original community may be little affected. Native species numbers may stay relatively constant for a long time and then suddenly collapse. The results indicate some possibly still concealed consequences of the spread of the invasive ladybird Harmonia axyridis (Pallas).

Sitobion avenae is the most abundant aphid that infests the ears of winter wheat in central Europe. Control of this pest will benefit from prediction of its maximum abundances on ears. We attempted to predict the maximum numbers of this species infesting the ears using earlier counts of this species in ears and on leaves using data collected in the Czech Republic in 2002–2014. The numbers of aphids on particular leaves and the ears were recorded at weekly intervals. The maximum numbers infesting the ears were significantly related to aphid counts on the ears made 1 week, 2 weeks and even 3 weeks before the peak. A regression based only on plots where there were aphids (non-zero aphid counts) recorded 3 weeks prior to the peak resulted in a critical number of ≥0.44 aphids/ear, which if exceeded resulted in a harmful maximum abundance of ≥5 aphids/ear at the peak. We also regressed maximum numbers infesting ears on numbers of S. avenae on leaves recorded 1, 2 and 3 weeks after earing, which all resulted in reliable predictions. Regression of maximum abundance on non-zero aphid counts on the leaves in week 3 after earing revealed a critical number of ≥0.59 aphids/tiller. Zero aphid counts resulted in only 3% of cases of a harmful maximum abundance in ears. Using records of the numbers on flag leaves, which make up 58% of the S. avenae population present on the foliage, also provided reliable predictions of maximum abundance in ears. Predicting maximum numbers of aphids from earlier records of the numbers of aphids on leaves or ears is thus possible. The prediction may be further improved by increasing the precision with which the numbers of aphids initially infesting the crop are estimated.

Simple Summary The carabid beetles are well known for the consumption of weed seeds in arable land, but how they choose the seeds is poorly known. In this work, we try to explain the patterns in preferences of 37 species of carabids based on eight seed properties of 28 species of seeds. Surprisingly, chemical properties of the seeds did not affect the preferences. Instead, preferences were driven mainly by seed structural properties. The importance of particular seed properties was also affected by the degree of predator specialization. Abstract Ground beetles are important invertebrate seed predators in temperate agro-ecosystems. However, there is a lack of information regarding which seed properties are important to carabids when they select seeds for consumption. Therefore, seed properties, such as size, shape, morphological defence, and chemical composition, were measured, and in addition to seed taxonomy and ecology, these data were used to explain carabid preferences. Carabid preferences were assessed using a multi-choice experiment with 28 species of weed seeds presented to 37 species of Carabidae. Multiple regression on distance matrices (MRM) was used to determine the importance of particular sets of seed properties for carabids. The analysis was conducted for the full set of carabids (37 species) as well as for subsets of species belonging to the tribes of Harpalini or Zabrini. For the complete set of species, seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties significantly explained carabid preferences (proportion of explained variance, R2 = 0.465). The model for Harpalini fit the data comparably well (R2 = 0.477), and seed dimensions, seed mass and seed coat properties were significant. In comparison to that for Harpalini, the model for Zabrini had much lower explanatory power (R2 = 0.248), and the properties that significantly affected the preferences were seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties. This result suggests that the seed traits that carabids respond to may be specific to taxonomic and likely relate to the degree of specialisation for seeds. This study contributes to understanding the mechanisms that determine the preferences of carabid beetles for seeds.

We surveyed ladybirds (Coleoptera: Coccinellidae) in 10 stands of Scots pine (Pinus sylvestris), all monoculture stands 5-100 years old, in western Slovakia, Central Europe, over two successive periods, October 2013 - March 2014 and October 2014 - March 2015. The winter in each period was exceptionally mild. Ladybirds were collected from the lower branches of pine trees using beating trays and were present in 61% of the 1040 samples (one sample containing ladybirds from 20 branches, 1 m long each). In total 3965 individuals of 20 species were recorded. Non-conifer dwelling species associated with broadleaved trees or herbaceous plants prevailed (45% of species), followed by conifer specialists (40%) and generalists (15%). Although 13 species were found at least in one winter month, December, January or February, only four of them, Exochomus quadripustulatus, Coccinella septempunctata, Harmonia axyridis and Hippodamia variegata, were recorded continually during both winters. The number of species, the abundance of all ladybirds and the abundance of dominant species (E. quadripustulatus, C. septempunctata and H. axyridis) decreased from late autumn towards winter and remained lowest during this most adverse time of the year for ladybirds. Overwintering species assemblages of ladybirds changed over time and varied with age of pine stand. Our results suggest that Scots pine in Central Europe supports species rich assemblages of ladybirds from late autumn to early spring and, being widely distributed, it could be suited to winter surveying of ladybirds at large spatial scales to reveal behavioural and ecological responses of species to changing weather or different climates.

Harmonia axyridis (Pallas), an invasive non-native species in central Europe, can outcompete other aphidophagous species. The distribution and abundance of H. axyridis vary depending on different host plants, and its effects on native coccinellid communities may change accordingly. The distribution and abundance of coccinellids in central Europe (50°N, 14°E) were investigated from 2010 to 2016. Coccinellids were counted at regular intervals on cereals (Avena, Hordeum, and Triticum), herbaceous plants (Matricaria and Urtica) and trees (Acer, Betula, and Tilia). Additionally, the occurrence over time of each species on these plants was assessed and used as an index of persistence. Across all years, the adults and larvae of H. axyridis were the dominant species of coccinellid on trees. However, H. axyridis was less abundant on herbaceous plants and cereals than on trees. Populations of native coccinellids and H. axyridis co-occurred on trees and persisted for the same length of time, while native coccinellids persisted longer than H. axyridis on herbaceous plants and cereals. Compared to 1976–1986, in the 2010s, the abundance of native species decreased on all plants by 50–70%. The presence of H. axyridis could be considered as a factor driving changes in the assemblages of native coccinellids.

A list of alien ladybird (Coleoptera: Coccinellidae) species to Europe was prepared and the history and circumstances of their introductions were determined. Currently there are twelve alien ladybird species in Europe, originating from Australian, Oriental, Nearctic, Palearctic and Afrotropical regions. All of the species were intentionally released as biological control agents and most are coccidophagous species. The aphidophagous Harmonia axyridis is the only ladybird regarded as invasive in Europe. The main factors leading to successful establishment were food relationship, living in different habitats in different geographical regions and geographic origin. We found that successful invaders, in their native areas, showed adaptability to a wide range of conditions compared to non-invasive species. Larger aphidophagous alien ladybirds were found to develop as fast as native species. Characteristics that did not differ between native and alien species are thermal requirements for development, fecundity and body size. However, unlike other alien ladybirds, H. axyridis had higher potential dispersal ability.

The development and reproduction, and maximum number of generations across seasons were ascertained for populations of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Central Europe. Number of generations was calculated using the thermal characteristics of development and summation of daily average air temperatures, in 2007–2016. This species can produce 2–3 generations per year. However, there is insufficient time for it to achieve its full reproductive potential. Delayed emigration from hibernacula (late April) shortened the period of seasonal activity by 1–6%. Breeding occurred from May to mid September. Oviposition continued into late summer, which left insufficient time for the late-hatching immatures to complete their development before the onset of winter. A high mobility, opportunistic use of prey patches and weak tendency to enter dormancy provide the potential for population increase by extending the period of development of immatures at the risk of failure if the cold period comes early.

1. We assessed the changes in abundance and community composition of native species of coccinellids (Coleoptera: Coccinellidae) on deciduous trees that occurred between 1970s and 2010s, in the Czech Republic. 2. As the composition of adult communities varies with host plant and season, coccinellids were sampled in May–June from Acer, Betula and Tilia trees using a standardised sweeping method. This was done before (1976–1986) and after (2011–2014) the arrival of Harmonia axyridis in 2006, with interim samples from a period immediately before it arrived in the Czech Republic (2002–2006). 3. Twenty-one native species were identified in the total sample of 2674 adults. The abundance of Adalia bipunctata, Coccinella quinquepunctata and Propylea quatuordecimpunctata decreased over the whole period sampled. Declines in abundance of these species were already evident prior to the arrival of H.axyridis. Recent declines in Adalia decempunctata and Calvia quatuordecimguttata followed the arrival H. axyridis. Their abundance was increasing prior to the arrival of H. axyridis, but decreased following its invasion and the latter species might have affected their decline. The abundance of only one species, Calvia decemguttata, increased. Although the abundance of many species decreased and the frequency of some species varied, the diversity of native coccinellid populations (Shannon index) was similar over the 40 years of this study. 4. The changes in species composition can in part be attributed to H. axyridis, the role of other factors (e.g. climate change, habitat degradation) in the long-term fluctuations in abundance of coccinellids should be considered in future assessments.

Flowers of dicotyledonous plants host communities of arthropod species. We studied the community associated with dandelion (Taraxacum section Ruderalia), a complex of apomictic micro-species abundant in central Europe. Identification of microspecies in the field was impracticable. These plants produce an abundance of flowers that host arthropod communities that are not yet fully documented. We investigated species occurrence, its diurnal and seasonal variation and some of the factors that determine the abundance of the dominant species. Insect and spiders were collected from 2010 to 2012 at a locality in Prague. Whole capitula were harvested at weekly intervals and resident arthropods were identified. Diurnal variation in insect presence and the effect of pollen and microclimate on some of the species were also examined. The insect community (> 200 species) consisted mainly of species of Hymenoptera (86 spp.), Coleoptera (56 spp.), Diptera (46 spp.) and Heteroptera (23 spp.). The most abundant were Thysanoptera (2 spp.). Pollen eaters/collectors and nectar feeders dominated over predators and occasional visitors. From April to mid-August, the insect community was dominated by Coleoptera, and later by Diptera and Hymenoptera. Except for Meligethes spp. and species breeding in the capitula, the insects occupied flowers during the daytime when the flowers were open (10-12 h in spring and only 2-4 h in late summer). The presence of Meligethes spp. in particular flowers was associated with the presence of pollen; the occurrence of Byturus ochraceus with pollen and flower temperature. Although pollination is not necessary, dandelion plants produce both nectar and pollen. The community of arthropods that visit dandelion flowers is rich despite their being ephemeral. The composition of local faunas of flower visitors, presence of floral rewards and flower microclimate are important factors determining the composition of the flower community.

1. Following its recent global spread, Harmonia axyridis (Coleoptera: Coccinellidae), an aphid predator of East Palearctic origin, dominated local coccinellid communities. While long-term trends in this change are well documented, little is known about seasonal changes. 2. Seasonal changes in communities of adult Coccinellidae were investigated in central Europe (Prague), from April to November in 2010–2014. The beetles were collected at 2-weekly intervals by net-sweeping particular stands of trees (Tilia spp., Acer spp. and Betula sp.). The numbers of beetles caught were recalculated per unit effort, and average species abundance and community richness, dominance and diversity were calculated for each 2-week period. 3. Frequencies of 21 established species varied throughout the vegetative season and general trends in this variation were similar in each of the 5 years of this study. In May–June the abundant species was Adalia decempunctata, which was later replaced by Harmonia axyridis as the most abundant species in late summer. Coccinella septempunctata colonized trees occasionally in summer. This sequence of species substitution occurred every year and was reset during winter. Species richness decreased and dominance increased during the course of each vegetative season. The diversity of the coccinellid community (Shannon index H′) significantly decreased during the course of the vegetative season. This was caused by a gradual increase in the dominance of H. axyridis, the abundance of which explained 88% of variation in H′. 4. The existence of a significant seasonal difference indicates that it is important to take this into consideration when comparing coccinellid communities.

In exothermal organisms, temperature is an important determinant of the rate of ecophysiological processes, which monotonically increase between the minimum (t d min) and maximum (t d max) temperatures typical for each species. In insects, t d min and t d max are correlated and there is a approximately 20°C interval (thermal window W T = t d max - t d min) between them over which insects can develop. We assumed that other exotherms have similar thermal windows because the thermal kinetics of their physiological processes are similar. In this study, we determined the thermal requirements for germination in plants. Seeds of 125 species of Central European wild herbaceous and crop plants were germinated at nine constant temperatures between 5 and 37°C, and the time to germination of 50% of the seeds D and rate of germination R (=1/D) were determined for each temperature and the Lactin model used to determine t d min, t d max, and W T. The average width of the thermal windows for seeds was significantly wider (mean 24°C, 95% CI 22.7-24.2°C), varied more (between 14.5 and 37.5°C) and development occurred at lower temperatures than recorded for insects. The limiting temperatures for germination, t d min and t d max, were not coupled, so the width of the thermal window increased with both a decrease in t d min and/or increase in t d max. Variation in W T was not associated with taxonomic affiliation, adult longevity, or domestication of the different species, but tends to vary with seed size. Plants are poor at regulating their temperature and cannot move to a more suitable location and as a consequence have to cope with wider ranges in temperatures than insects and possibly do this by having wider thermal windows.The study indicated specificity of W T in different exotherm taxa and/or their development stages.

The harlequin ladybird beetle Harmonia axyridis (Coleoptera, Coccinellidae) has invaded and established in Slovakia. Following unintentional introduction in 2008, the spread of the alien coccinellid was very fast. By the end of 2009, it was recorded across the whole country, and by the end of 2012 it was widely distributed and common in various habitats, particularly gardens, orchards and urban areas, where it was most frequent on trees. The rate of eastward spread was approximately 200 km year-1, similar to the overall rate of spread in Europe. Between 2008 and 2012, the coccinellid was recorded in a total of 153 localities, in altitudes ranging from 98 to 1,250 m. Most records of this species were made in lowlands, hilly areas and valleys separating mountain ridges. However, it was only rarely documented in areas above 700 m a.s.l. The non-melanic colour form (f. succinea) was dominant along alongitudinal transect including eight urban areas across Slovakia, with the frequency of melanic forms (f. spectabilis and f. conspicua together) between 6.3 and 19.2% and a median equal to 10.5%. The invasion history and distribution of H. axyridis in Slovakia are discussed with regard to the time sequence of records, rate of spread, altitudinal distribution, anthropogenic dispersal, effective recording, proportion of melanic forms and other relevant aspects associated with the spread of this successful invader.

Several methods of seed exposure are used in seed predation studies, but how these methods influence the results remains poorly studied. In this article, two commonly used methods of seed exposure – seed cards and plasticine trays – were compared in the field and in the laboratory using three species of weed seeds. In the field, cards or trays with seeds were exposed either with or without cages to keep vertebrates out and either with or without impermeable roofs to provide protection from the weather. The overall seed retrieval from the control stands varied significantly between the methods of seed exposure, roof treatment and the species of seeds, and the scatter in the seed retrieval increased or decreased monotonically with the temperature or precipitation for some species of seeds. This indicates that the controls were more or less relevant depending on the weather conditions and species. The seed removal from cards varied between the species of seeds. The effect of exclosure cages indicated that invertebrates were the dominant seed predators of Capsella bursa-pastoris, while in Poa annua and Stellaria media both vertebrates and invertebrates were important. Higher seed removal from plasticine trays compared to seed cards was found for all three species of seeds, and placing roofs over the seeds affected seed removal in C. bursa-pastoris and P. annua. In the laboratory, seed consumption varied with the method of exposure in 10 out of 12 combinations of seed species and predator (two species of carabids and two species of isopods). The overall tendency was the opposite of the field observations: seed consumption was higher for seeds on filter paper and cards compared to seeds on tin trays. We conclude that seed cards are more convenient for short term studies in the field, while tin trays are useful in laboratory multi-choice experiments. To measure the realistic consumption of invertebrate predators in the laboratory, filter paper seems to be the best option as it does not present an obstacle to predators eating the seed. Using roofs introduced further bias regarding the estimates of seed removal in the field and thus should be avoided.

Coccinellids (Coleoptera: Coccinellidae) provide important ecosystem services as biocontrol agents in contributing to the regulation of key agricultural pests. It is generally accepted that biodiversity of native coccinellid communities has been declining during recent decades. Here, we present the results of a long-term study of coccinellid communities and report an attempt to determine whether recent changes in land use have affected their composition. Coccinellids were sampled in cereal crops, on wild herbaceous plants and deciduous trees during two periods (1976–1983 and 2002–2010). There are similar species-rich communities of coccinellids on trees and wild herbaceous plants (average numbers of species 3.18 and 3.06, respectively) and a poorer community on cereals (2.63). Only a few species, associated with particular types of vegetation, differed in their absolute abundance in the first and second period. There was no obvious cause of this variation in abundance. Diversity of coccinellid communities was higher in the second than in the first period (Shannon-Wiener index 1.32 and 1.14 respectively), although the number of individuals was lower (average catch per sampling session 10.0 and 18.6 individuals respectively). Over the 35 years of this study, the compositions of the communities remained essentially similar with the numbers of particular species more closely correlated in the two periods on cereals (R2 = 0.97) than on herbaceous plants (R2 = 0.74) and trees (R2 = 0.67).

Dandelion (Taraxacum officinale) is an abundant Asteraceae species of grassland and vasteland stands. Through the vegetative season each plant produces a number of short-lived inflorescens. Final stage of inflorescence development is seed dispersal that lasts 2 days. Despite its ephemeral persistence, inflorescences at this period host abundant fauna. In 2005–2010 the inflorescences were collected in regular intervals in May–October, at Prague-Ruzyně and selected sites of western Czech Republic. Typical fauna consist of Heteroptera adults and larvae (34 species), phytophagans feeding on receptacle and seeds (mainly Miridae, Pentatomidae, Rhopalidae) and predators consuming thrips (Anthocoridae). The composition of Heteroptera fauna varies through the vegetative season, and its abundance decreases with increasing altitude of the locality. Other fauna are relics of species consuming seeds in the post-flowering phase of inflorescence maturation (mainly Thysanoptera) and occasional visitors with no trophic relationship to dandelion (Coleoptera, Diptera, Hymenoptera, Araneae). The reasons for association of phytophagous Heteroptera and dandelion may be preferences for seed consumption and chemicals present in plant tissues and possibly used for sequestration of aposematic substances.

Because of their services to agriculture most ladybirds (Coleoptera: Coccinellidae) are intensively studied predators of mainly phytophagous pests. The study of the long-term variation in the composition of their communities was stimulated by recent dramatic changes in the abundance of some species. We review and evaluate possible effects of the main causes cited in the literature. Agricultural and habitat changes (particularly urbanization) affect coccinellid abundance, both negatively and positively. In the temperate zone dominant species occur most frequently associated with abundant prey populations on crops, weeds and planted stands of trees resulting from human activity. Invasive non-native species of coccinellids may endanger native species through intraguild predation or competition for resources, but their supposed serious negative effects on native species can differ considerably. Climatic change may influence coccinellid species in several ways, including indirect effects through lower trophic levels and desynchronisation of the phenologies of host plants, prey and coccinellid populations. In the near future we do not expect climate warming to have important effects on ladybird diversity globally, but local changes in the composition of coccinellid communities and abundance of particular species could occur.