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The greater wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae), has gathered widespread interest in the biomedical research community as an alternative non-mammalian model to study bacterial and fungal infections in humans. Nevertheless, most laboratories rely on commercial breeding companies that grow these larvae in bulk. Variation in rearing conditions between these companies and shipping of the larvae affects the response of G. mellonella to infection, both decreasing the reproducibility and comparability of infection experiments across laboratories. To unlock the full potential of G. mellonella as an infection model, standardized rearing is essential to produce healthy larvae of uniform quality. To this end, we developed an optimized protocol using a high-nutritional artificial diet and cost-effective housing solutions to ensure optimal conditions during each stage of the G. mellonella life cycle. This resulted in the rapid generation of larvae with a short larval phase, large size, and increased weight compared to other protocols and commercial larvae. A survival analysis comparing the standardized larvae with commercially obtained larvae showed significantly higher survival of standardized reared larvae after infection with Candida albicans (CP Robin) Berkhout (Saccharomycetales), proving the higher quality of standardized reared larvae.

Damage by herbivores often modifies plant structure and physiology, which may change the behaviour and performance of future herbivores. Here, we studied such interactions among the major coconut pest, the mite Aceria guerreronis (Acari: Eriophyidae), and two minor pests, the mite Steneotarsonemus concavuscutum (Acari: Tarsonemidae) and the moth Atheloca bondari (Lepidoptera: Pyralidae). All these species develop in the meristematic zone of coconuts, which is difficult to access because of the small opening between the epicarp and perianth. Both mites cause necrosis on the epicarp of the nuts, which may facilitate access to the meristematic zone by caterpillars of the moth. However, the caterpillars co-occur predominantly with A. guerreronis and not with S. concavuscutum. We show that caterpillars did not colonize nuts without mites and colonized nuts with A. guerreronis most frequently, in agreement with the openings caused by this mite and caterpillar size. When the opening between epicarp and perianth was artificially increased, caterpillars also colonized nuts without mites and nuts with S. concavuscutum. When offered a choice, caterpillars preferred nuts with easy access to the meristematic region, regardless of the presence of mites. Caterpillars performed better on the A. guerreronis-infested nuts than on other nuts, but moth females did not preferentially oviposit in coconut bunches infested with mites. Hence, caterpillars, not adults, select suitable feeding sites within a bunch of coconuts, and A. guerreronis facilitates the infestation of coconuts by A. bondari. We discuss how damage by mites affects the relevance of A. bondari as a coconut pest.

Herbivores select host plants depending on plant quality and the presence of predators and competitors. Competing herbivores change host plant quantity through consumption, but they can also change plant quality through induction of plant defences, and this affects the performance of herbivores that arrive later on the plant. Some herbivores, such as the spider mite Tetranychus evansi, do not induce, but suppress plant defences, and later-arriving herbivores can profit from this suppression. It has been suggested that the dense web produced by this spider mite serves to prevent other herbivores to settle on the plant and benefit from the suppressed defences. Here, we confirmed this by studying the preference and performance of the whitefly Bemisia tabaci, a generalist herbivorous pest. To disentangle the effects through changes in plant defences from the effects of spider-mite web, we included treatments with a strain of the closely-related web-producing spider mite T. urticae, which induces plant defences. Whiteflies did perform worse on plants with defences induced by T. urticae, but, in contrast to other herbivores, did not perform better on plants with defences suppressed by T. evansi. Moreover, the web of both spider mites reduced the juvenile survival of whiteflies, and whiteflies avoided plants that were covered with web. Hence, whitefly performance was not only affected by plant quality and induced plant defences, but also through the web produced by spider mites, which thus serves to protect against potential competitors, especially when these could profit from the suppression of plant defences by the mites.

It has become clear that omnivorous predators can induce plant defences that affect the performance and host plant choice of herbivores. They are also known to induce the production of plant volatiles that can affect the behaviour of herbivores searching for plants. These volatiles may also affect the searching behaviour of other predators, which was investigated here. The predatory mite Phytoseiulus persimilis preferred plants previously exposed to the omnivorous mirid Macrolophus pygmaeus over clean plants. The mites were equally attracted to plants previously exposed to the omnivore and subsequently infested by spider mites (Tetranychus urticae, prey of the predatory mite and the omnivore) and plants infested with spider mites alone. Moreover, the mites were more attracted to plants infested with prey and subsequently exposed to the omnivore than plants infested with prey but not exposed to the omnivore. The predatory mites were also significantly more attracted to plants on which the omnivores were still present. Experience of the predatory mites with volatiles from plants previously exposed to the omnivore and without prey resulted in a loss of the preference for volatiles emitted by plants exposed to the omnivore. Analysis of the volatiles showed that plant exposure to omnivores induced qualitative and quantitative changes in the volatile blend. Together, these results suggest that omnivorous predators induce the production of plant volatiles that can interfere with the searching behaviour of other predators. The consequences of such interference for biological pest control remain to be investigated.

From the Netherlands, five more desmid species giving rise to taxonomic confusion are described as new to science: Cosmarium neocrenatum, C. neonotabile, C. palatiniforme, C. regnesiforme and C. sphagnicoliforme. The affinity with similarly looking taxa is discussed.

In a recent paper, "Environmental DNA: What's behind the term? Clarifying the terminology and recommendations for its future use in biomonitoring," Pawlowski et al. argue that the term eDNA should be used to refer to the pool of DNA isolated from environmental samples, as opposed to only extra-organismal DNA from macro-organisms. We agree with this view. However, we are concerned that their proposed two-level terminology specifying sampling environment and targeted taxa is overly simplistic and might hinder rather than improve clear communication about environmental DNA and its use in biomonitoring. This terminology is based on categories that are often difficult to assign and uninformative, and it overlooks a fundamental distinction within eDNA: the type of DNA (organismal or extra-organismal) from which ecological interpretations are derived., Molecular Ecology, 30 (19), ISSN:0962-1083, ISSN:1365-294X

1. Many animals can actively redress nutrient imbalances in their diet to maximise performance. However, food items are commonly patchily distributed in nature, thus, animals often need to commute between prey patches to mix their diet.2. We previously found that females of two species of predatory mites showed a higher oviposition rate when feeding on a mixture of eggs of co-occurring phytophagous mites than on each prey separately. Besides, they searched for such a prey mixture on artificial arenas.3. In nature, however, the two prey species are found on different parts of their host plant; hence, the predators need to commute between plant parts to obtain a mixed diet.4. Here, we show that the reproduction of one of these predators was highest on mixtures consisting of various proportions of these prey, and was lower on single diets and on a mixture with a high proportion of one of the two prey. The predators consumed prey eggs in proportions differing from those offered, suggesting that they actively selected prey to obtain a mixed diet. 5. We found that the oviposition of the predator was lower on plants inoculated with either of the two prey species alone than on plants on which the eggs of the two prey species occurred on separate leaves of the same plant, forcing the predators to commute between the two prey.6. We conclude that the predators actively searched for a mixed diet consisting of prey that were spatially separated on a plant.

Sexual signal evolution is shaped by whether only one or both sexes execute mate choice. When mate choice by both sexes is considered, the same signalling modality is generally inferred for males and females. In the noctuid moth Chloridea (Heliothis) virescens (Lepidoptera: Noctuidae), both sexes may be signallers and responders, as both emit a sex-specific pheromone. Male mate choice is based on the female sex pheromone, perceived via the antennae, and has been well documented. However, whether females choose partners and whether their choice is based on the male pheromone are unknown. Since female mate choice is expected when males vary in quality, we reared males on two different larval diets that affected their size, which correlated positively with their fitness. When given a choice, more females mated with larger than with smaller males, and these females produced more eggs and larvae. Female choice was not affected by the absolute amount or composition of the male pheromone. Moreover, we found that antennaless females mated as readily as intact females, indicating that antennal sensory input is not required for females to mate. To determine whether females make an active choice, we studied courtship behaviour in detail and observed that females determined the outcome of courtship by moving away from the male (avoidance) or by facilitating copulation with an abdominal bend (acceptance). Additionally, we discovered that tactile sensory stimuli may be involved during courtship. Because tactile interactions may mediate contact-based (chemical) communication, we also investigated putative pheromone components on moth legs, but found no differences between the sexes. Together, our study is the first comprehensive investigation of female mate choice in a heliothine moth.

Plant quality for herbivores is usually evaluated with molecular and physiological techniques and with herbivore performance bioassays. These performance assays are usually done either on intact plants or on detached plant parts, such as leaves, leaflets, and leaf discs. It is thus far unclear how performance experiments on intact plants and on plant parts compare. Plant quality may change in detached plant parts because of the mechanical wounding inflicted, which may induce plant defences. Moreover, plant defences are often systemic, i.e., involving the entire plant, and may not be fully expressed in leaf discs. We investigated the effects of plant quality on the performance of a phytophagous mite on intact plants and on leaf discs. Plant quality was manipulated by infesting intact tomato plants (Solanum lycopersicum L., Solanaceae) either with a strain of the spider mite Tetranychus urticae Koch (Acari: Tetranychidae) that induces plant defences, or with Tetranychus evansi Baker & Pritchard, which suppresses defences, and using uninfested tomato plants as control. We subsequently evaluated the oviposition rate and survival of individual females of T. evansi on intact plants and on leaf discs as a measure of herbivore performance. The mites produced fewer eggs on detached leaf discs than on intact plants. However, the oviposition rate of T. evansi was lower on plants infested with the inducer T. urticae than on plants infested with the suppressor T. evansi, and than on uninfested plants, both on leaf discs and on intact plants. We conclude that both intact plants and leaf discs can be used to evaluate the effects of plant quality on performance of this herbivore.

1. Herbivore densities can be regulated by bottom-up and top-down forces such as plant defences and natural enemies, respectively. These forces can interact with each other to increase plant protection against herbivores; however, how much complementarity exists between bottom-up and top-down forces still remains to be fully elucidated. Particularly, because plant defences can hinder natural enemies, how these interactions affect herbivore performance and dynamics remains elusive.2. To address this topic, we performed laboratory and greenhouse bioassays with herbivorous mite pests and predatory mites on mutant tomato plants that lack defensive hairs on stems and leaves. Particularly, we investigated the behaviour and population dynamics of different phytophagous mite species in the absence and presence of predatory mites.3. We show that predatory mites do not only perform better on tomatoes lacking defensive hairs but also that they can suppress herbivore densities better and faster on these hairless plants. Hence, top-down control of herbivores by natural enemies more than compensated the reduced bottom-up herbivore control by plant defences.4. Our results lead to the counter-intuitive insight that removing, instead of introducing, plant defence traits can result in superior protection against important pests through biological control. Read the free Plain Language Summary for this article on the Journal blog.

Parasites can play an important role in host sexual selection. According to the ‘Hamilton & Zuk hypothesis’, females acquire benefits from choosing parasite-free or parasite-resistant males based on their secondary sexual traits (e.g. colourful plumage) as indicators of heritable parasite resistance. However, females may also gain benefits by avoiding sexually transmitted parasites or acquiring more parental care, higher quality sperm and nuptial gifts provided by uninfected males. Here we tested how the presence of the Ophryocystis elektroscirrha-like parasite (OE-like) affected longevity, reproduction and mating frequency in the moth Helicoverpa armigera. We found that OE-like infection affected the sexes differently: the life span of uninfected males was reduced when paired with infected females, while these females had higher reproductive output than when paired with infected males. These results suggest some form of terminal investment by infected males. When we assessed the effect of OE-like infections on female calling behaviour and sex pheromone signal, we found that the OE-like parasite did not affect the female's pheromone signal in quality or quantity, but it did reduce her reproductive output, suggesting that infected females reallocate resources to maintain an attractive sex pheromone signal. In mate choice experiments, when females were the choosing sex, infected females mated significantly more often with uninfected than with infected males. Since these females produced approximately 12% more offspring, and uninfected females did not prefer uninfected or infected males, these results indicate female choice for uninfected males. Unexpectedly, when we compared the calling behaviour of the two females that were caged together, we found that infected females called significantly earlier than uninfected females, while this was not the case when females were housed alone. Thus, OE-like infection affects reproductive strategies in both males and females, but in different ways, which suggests sex-specific parasite-mediated selection.

Endosymbiotic bacteria can induce parthenogenesis in many haplo-diploid species, but little is known about their role in asexual reproduction in diplodiploids. Bacteria are essential for reproduction in the asexual lineages of springtails and booklice, and possibly some weevils, but whether they are the causative agent of parthenogenesis remains to be proven. This would require comparing unisexual forms and their closely related bisexual species, but such model species are very rare. Empoasca leafhoppers from the Madeira Archipelago provide an excellent case to test whether bacterial infections can cause parthenogenesis. Here we examined the diversity of the sex-distorting bacteria, Wolbachia, Cardinium, Rickettsia, and Arsenophonus, in three apomictic morphotypes (A, B, C) and three bisexual relatives of Empoasca. Wolbachia of group B was present in all unisexual and bisexual species. Rickettsia were the only bacteria restricted to the three unisexual forms, suggesting an association between infection and asexual reproduction. In addition, we found Asaia for the third time in the Cicadellidae, although this may have little to do with the reproductive mode of its host. Adult females of morphotype C reared on plants watered with tetracycline solution did not result in the production of male offspring. To our knowledge, this is the first study to suggest a possible association between bacterial infection and parthenogenesis in apomictic XO/XX diplodiploid bisexual species based on a range of sex ratio-distorting bacteria.

Species delimitation is one of the most fundamental processes in biology. Biodiversity undertakings, for instance, require explicit species concepts and criteria for species delimitation in order to be relevant and translatable. However, a perfect species concept does not exist for Fungi. Here, we review the species concepts commonly used in Basidiomycota, the second largest phylum of Fungi that contains some of the best known species of mushrooms, rusts, smuts, and jelly fungi. In general, best practice is to delimitate species, publish new taxa, and conduct taxonomic revisions based on as many independent lines of evidence as possible, that is, by applying a so-called unifying (or integrative) conceptual framework. However, the types of data used vary considerably from group to group. For this reason we discuss the different classes of Basidiomycota, and for each provide: (i) a general introduction with difficulties faced in species recognition, (ii) species concepts and methods for species delimitation, and (iii) community recommendations and conclusions.

Diaphorina citri Kuwayama (Hemiptera: Psyllidae) transmits the bacteria associated with Huanglongbing, an incurable and lethal disease affecting citrus productivity and fruit quality worldwide. This vector is prominently phototactic and uses visual cues to find host plants. Yellow sticky traps are used for its monitoring, but their efficiency is limited, especially at low population densities. Diaphorina citri can be captured at night when light is provided and it is attracted to UV light. One way to increase the attraction of D. citri is therefore combining sticky traps with LEDs of specific colors at night, but more information about attractiveness of UV and colors combined with UV is needed. Moreover, information on the attraction of the main parasitoid of D. citri, Tamarixia radiata Waterson (Hymenoptera: Eulophidae) to UV and other light colors is lacking. We examined the attraction of males and females of D. citri to LED lights of different colors but comparable intensities separately or combined with ultraviolet (UV). The non-UV colors alone did not differ in attractiveness, whereas green, light blue and red light became more attractive when combined with UV. However, none of these color combinations were more attractive than UV alone. The parasitoid T. radiata was also attracted to UV LEDs. Female parasitoids were equally attracted to UV during day and night, but males were more attracted at night. These results suggest that the effectiveness of the commonly used yellow sticky traps can be increased by combining them with UV LEDs at night, and the parasitoid of D. citri may also be attracted. On the one hand, attraction of parasitoids to the traps may help monitoring their presence, but on the other hand, it may affect biological control by this natural enemy.

The predictability of evolution is expected to depend on the relative contribution of deterministic and stochastic processes. This ratio is modulated by effective population size. Smaller effective populations harbor less genetic diversity and stochastic processes are generally expected to play a larger role, leading to less repeatable evolutionary trajectories. Empirical insight into the relationship between effective population size and repeatability is limited and focused mostly on asexual organisms. Here, we tested whether fitness evolution was less repeatable after a population bottleneck in obligately outcrossing populations of Caenorhabditis elegans. Replicated populations founded by 500, 50, or five individuals (no/moderate/strong bottleneck) were exposed to a novel environment with a different bacterial prey. As a proxy for fitness, population size was measured after one week of growth before and after 15 weeks of evolution. Surprisingly, we found no significant differences among treatments in their fitness evolution. Even though the strong bottleneck reduced the relative contribution of selection to fitness variation, this did not translate to a significant reduction in the repeatability of fitness evolution. Thus, although a bottleneck reduced the contribution of deterministic processes, we conclude that the predictability of evolution may not universally depend on effective population size, especially in sexual organisms. ispartof: EVOLUTION vol:76 issue:8 pages:1896-1904 ispartof: location:United States status: published

Despite the fact their coloration functions as an aposematic signal, and is thus expected to be under stabilizing selection, hibiscus harlequin bugs (Tectocoris diophthalmus) show an impressive level of variation in their iridescent coloration both within and between populations. To date the heritability of coloration in this species remains unknown. Here we focus on a single population in New South Wales (the southern part of this species’ Australian range), with the greatest colour variation. We reared full-sib families of known pedigree in the laboratory and analysed the extent of iridescent coloration at adulthood. We then looked for evidence of heritability, condition dependence and antagonistic sexual selection acting on colour in this species. We found significant heritability in the extent of iridescent coloration for both sexes, as well as in development time and body size, but no evidence that condition dependence played a role in the determination of adult coloration. There was, however, a sex by genotype interaction for iridescent cover, in the form of a negative intersexual genetic correlation: in families where sons had high iridescent cover the daughters had low, and vice versa. Our results suggest that different selective pressures may act on coloration in males and females of this species.

The six synonyms currently accepted under Saccharomycodes ludwigii were investigated for by phenotypic properties, however, the sequence diversity of the rRNA and protein coding genes have not yet been determined. Nine strains including the type strains of synonyms of S. ludwigii deposited in the CBS yeast collection, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands, were analyzed using a multi-locus sequence analysis (MLSA) approach that included sequences of 18S ribosomal RNA (rRNA), the D1/D2 domains of the 26S rRNA, the ITS region (including the 5.8S rRNA) and fragments of genes encoding the largest subunit of the RNA polymerase II (RPB1 and RPB2) and translation elongation factor 1-α (TEF1). Our results showed that the nine strains have identical D1/D2, 18S and RPB2 sequences and similar ITS, RPB1 and TEF1 sequences, which indicated that they are conspecific. In addition, a novel species of Saccharomycodes, S. pseudoludwigii sp. nov. (type CGMCC 2.4526 T) that was isolated from fruit and tree bark in China, is proposed. The MycoBank number of this new species is MB 811,650.

The spatial segregation of species is fundamental to ecosystem formation and stability. Behavioural strategies may determine where species are located and how their interactions change the local environment arrangement. In response to stimuli in the environment, individuals may move in a specific direction instead of walking randomly. This behaviour can be innate or learned from experience, and allow the individuals to conquer or the maintain territory, foraging or taking refuge. We study a generalisation of the spatial rock-paper-scissors model where individuals of one out of the species may perform directional movement tactics. Running a series of stochastic simulations, we investigate the effects of the behavioural tactics on the spatial pattern formation and the maintenance of the species diversity. We also explore a more realistic scenario, where not all individuals are conditioned to perform the behavioural strategy or have different levels of neighbourhood perception. Our outcomes show that self-preservation behaviour is more profitable in terms of territorial dominance, with the best result being achieved when all individuals are conditioned and have a long-range vicinity perception. On the other hand, invading is more advantageous if part of individuals is conditioned and if they have short-range neighbourhood perception. Finally, our findings reveal that the self-defence strategy is the least jeopardising to biodiversity which can help biologists to understand population dynamics in a setting where individuals may move strategically., Comment: 11 pages, 8 figures

Candiduria is common among patients admitted to intensive care units (ICUs); however, clinical and microbiological data are limited, which accounts for non-compliance with international guidelines, including over treatment of asymptomatic candiduria that promotes antifungal resistance. This prospective study included adult patients admitted to ICUs of five referral hospitals in Shiraz, Iran, during 2016-2018. Species were identified by MALDI-TOF MS, and antifungal susceptibility was assessed according to CLSI M27-A3/S4. Among 2086 patients, 162 and 293 developed candiduria and bacteriuria, respectively. In total, 174 yeast isolates were collected; 88.5% were Candida albicans (91/174; 52.2%), C. glabrata (38/174; 21.8%), and C. tropicalis (25/174; 14.3%). Antifungal resistance was rare; only two isolates (one C. tropicalis and one C. krusei) were fluconazole resistant. Symptomatic candiduria was noted in 31.4% of patients (51/162); only 37% (19/51) of them were treated and 36.82% (7/19) showed fluconazole therapeutic failure. Two symptomatic patients developed candidemia shortly after candiduria. Among asymptomatic patients, 31.5% (35/111) were overtreated with fluconazole. The mortality rate was 25.3% (41/162); it did not differ between symptomatic and asymptomatic patients. Our results indicate that deviation from standard-of-care treatment for candiduria is a matter of concern given the high rate of fluconazole therapeutic failure among patients with symptomatic candiduria.LAY SUMMARY: Candiduria is an underestimated clinical presentation among critically ill patients and detailed data are scarce in this regard. Given the high rate of fluconazole therapeutic failure and development of candidemia in some cases, the mistreatment of candiduria should not be overlooked by clinicians.

Sexual signals are important in speciation, but understanding their evolution is complex as these signals are often composed of multiple, genetically interdependent components. To understand how signals evolve, we thus need to consider selection responses in multiple components and account for the genetic correlations among components. One intriguing possibility is that selection changes genetic correlations between components under selection and those not under selection, reducing evolutionary constraints. However, this hypothesis remains largely untested empirically. In this study, we investigate the evolutionary response of the multi-component female sex pheromone blend of the moth Heliothis subflexa to 10 generations of artificial selection. We observed a selection response of about 3/4s of a phenotypic standard deviation in the components under selection. Interestingly, other pheromone components that are biochemically and genetically linked to the components under selection did not change. We found that this component-specific selection response was likely facilitated due to reduced genetic coupling between the component under selection and the components not under selection, resulting from changes in genetic covariances within the 10 generations of selection. Our findings provide rare empirical support for an intriguing mechanism by which a sexual signal can respond to selection without possible constraints from indirect selection responses. SUMMARY STATEMENT This study reveals a mechanism that can facilitate evolution of sex pheromone components under selection independent of other components of the sex pheromone that are not under selection.

Sexual selection in animals has been mostly studied in species in which males are signalers and females are choosers. However, in many species, females are (also) signalers. In species with non-signaling females, virgin females are hypothesized to be less choosy than mated females, as virgins must mate to realize fitness and the number of available males is generally limited. Yet, when females signal to attract males, mate limitation can be overcome. We tested how virgin and mated females differ in their calling behavior, mating latency, and in mate choice, using the tobacco budworm Chloridea (Heliothis) virescens as an example for a species in which females are not only choosers but also signalers. We found that virgin females signaled longer than mated females, but virgin and mated signaling females were equally ready to mate, in contrast to non-signaling females. However, we found that virgin signaling females showed weaker mate preference than mated females, which can be explained by the fact that females increase their fitness with multiple matings. Mated females may thus further increase their fitness by more stringent mate selection. We conclude that signaling is a crucial aspect to consider when studying female mate choice because signaling may affect the number of available mates to choose from. ispartof: ECOLOGY AND EVOLUTION vol:12 issue:4 ispartof: location:England status: published

Understanding the impact of historical and demographic processes on genetic variation is essential for devising conservation strategies and predicting responses to climate change. Recolonization after Pleistocene glaciations is expected to leave distinct genetic signatures, characterised by lower genetic diversity in previously glaciated regions. Populations’ positions within species ranges also shape genetic variation, following the central-marginal paradigm dictating that peripheral populations are depauperate, sparse and isolated. However, the general applicability of these patterns and relative importance of historical and demographic factors remains unknown. Here, we analysed the distribution of genetic variation in 91 native species of North American plants by coupling microsatellite data and species distribution modelling. We tested the contributions of historical climatic shifts and the central-marginal hypothesis on genetic diversity and structure on the whole data set and across subsets based on taxonomic groups and growth forms. Decreased diversity was found with increased distance from potential glacial refugia, coinciding with the expected make-up of postglacially colonised localities. At the range periphery, lower genetic diversity, higher inbreeding levels and genetic differentiation were reported, following the assumptions of the central-marginal hypothesis. History and demography were found to have approximately equal importance in shaping genetic variation.

Dispersal is the main determinant of the dynamics and persistence of predator-prey metapopulations. When defining dispersal as a predator exploitation strategy, theory predicts the existence of a continuum of strategies: from some dispersal throughout the predator-prey interaction (the Milker strategy) to dispersal only after the prey had been exterminated (the Killer strategy). These dispersal strategies relate to differences in prey exploitation at the population level, with more dispersal leading to longer predator-prey interaction times and higher cumulative numbers of dispersing predators. In the predatory mite Phytoseiulus persimilis, empirical studies have shown genetic variation for prey exploitation as well as for the timing of aerial dispersal in the presence of prey. Here, we test whether artificial selection for lines that differ in timing of dispersal also results in these lines differing in prey exploitation. Six rounds of selection for early or late dispersal resulted in predator lines displaying earlier or later dispersal. Moreover, it resulted-at the population level-in predicted differences in the local predator-prey interaction time and in the cumulative numbers of dispersers in a population dynamics experiment. We pose that timing of dispersal is a heritable trait that can be selected in P. persimilis, which results in lines that show quantitative differences in local predator-prey dynamics. This opens ways to experimentally investigate the evolution of alternative prey exploitation strategies and to select for predator strains with prey exploitation strategies resulting in better biological control.

Chlorogenic acid (CHA) and gallic acid (GA) are safe natural phenolic compounds that are used as enhancers of some drugs in influencing antioxidant, anticancer, and antibacterial activities. Among fungi, Candida spp. and Malassezia spp. are characterized by an increasing prevalence of multidrug resistance phenomena and by a high morbidity and mortality of their infections. No data are available about the efficacy of CHA and GA combined with azoles on the antifungal susceptibility and on the virulence of both fungi. Therefore, their antifungal and antivirulence effects have been tested in combination with fluconazole (FLZ) or ketoconazole (KTZ) on 23 Candida spp. and 8 M. furfur isolates. Broth microdilution chequerboard, time-kill studies, and extracellular enzymes (phospholipase and hemolytic) activities were evaluated, displaying a synergistic antifungal action between CHA or GA and FLZ or KTZ on C. albicans, C. bovina, and C. parapsilosis, and antagonistic antifungal effects on M. furfur and Pichia kudriavzevii (Candida krusei) isolates. The time-kill studies confirmed the chequerboard findings, showing fungicidal inhibitory effect only when the GA was combined with azoles on Candida strains. However, the combination of phenolics with azoles had no effect on the virulence of the tested isolates. Our study indicates that the combination between natural products and conventional drugs could be an efficient strategy for combating azole resistance and for controlling fungistatic effects of azole drugs.

Heterogeneous ice nucleation (HIN) triggered by mineral surfaces typically exposed to various ions can have a significant impact on the regional atmosphere and climate. However, the dependence of HIN on the nature of the mineral surface ions is still largely unexplored due to the complexity of mineral surfaces. Because K+ on the atomically flat (001) surface of mica can be readily replaced by different cations through ion exchange, muscovite mica was selected; its simple nature provides a very straightforward system that can serve as the model for investigating the effects of mineral surface ions on HIN. Our experiments show that the surface (001) of H+-exchanged mica displays markedly higher HIN efficiencies than that of Na-/K-mica. Vibrational sum-frequency generation spectroscopy reveals that H-mica induces substantially less orientation ordering than Na-/K-mica within the contact water layer at the interface. Molecular dynamics simulations suggest that the HIN efficiency of mica depends on the positional arrangement and orientation of the interfacial water. The formation of the hexagonal ice Ih basal-type structure in the first water layer atop the mica surface facilitates HIN, which is determined by the size of the protruding ions atop the mica surface and by the surface adsorption energy. The orientational distribution is optimal for HIN when 25% of the water molecules in the first water layer atop the mica surface have one OH group pointing up and 25% have one OH group pointing down, which, in turn, is determined by the surface charge distribution.

Antifungal susceptibility profiles of rare Saccharomycotina yeasts remain missing, even though an increase in prevalence of such rare Candida species was reported in candidemia. Majority of these rare yeast species carry intrinsic resistances against at least one antifungal compound. Some species are known to be cross-resistant (against multiple drugs of the same drug class) or even multi-drug resistant (against multiple drugs of different drug classes). We performed antifungal susceptibility testing (AFST) according to EUCAST broth microdilution for 14 rare species (Clavispora lusitaniae, Candida intermedia, Candida auris, Diutina rugosa, Wickerhamiella pararugosa, Yarrowia lipolytica, Pichia norvegensis, Candida nivariensis, Kluyveromyces marxianus, Wickerhamomyces anomalus, Candida palmioleophila, Meyerozyma guilliermondii, Meyerozyma caribbica, and Debaryomyces hansenii) known to cause candidemia. In total, 234 isolates were tested for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Amphothericin B had the broadest efficiency against the 14 tested rare yeast species, while high minimum inhibitory concentrations (MICs) against azole drugs and echinocandins were common. Voriconazole was the most efficient azole drug. Multidrug resistance was observed for the species C. auris and K. marxianus. Multidrug resistant individual isolates were found for Y. lipolytica and M. caribbica. In conclusion, the observed high MIC values of the rare Saccharomycotina species tested limit antifungal treatment options, complicating the management of such infections.

Using environmental DNA (eDNA) metabarcoding, we compared fish diversity in two distinct water bodies within the Yangtze River Basin with known populations of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis; YFP): the Tian-e-Zhou Reserve and Poyang Lake. We aimed to create a fish surveying tool for use in the Yangtze River Basin, while also gaining a better understanding of the prey distribution and diversity within two of the remaining strongholds of YFP. 16S rRNA universal primers were developed to amplify fish eDNA. After high-throughput sequencing and stringent data filtering, we identified a total of 75 fish species (6 orders, 9 families, 57 genera) across seasons and regions. Nine of the 75 fish species were among the 28 known YFP prey species, three of which were detected in all water samples. Our eDNA metabarcoding identified many species that had been previously captured using traditional netting practices, but also numerous species not previously collected in these water bodies. Fish diversity was higher in Poyang Lake than in Tian-e-Zhou Reserve, as well as higher in the spring than in summer. These methods provide a broadly applicable tool to quantify fish diversity and distributions throughout the Yangtze River Basin, and to inform conservation strategies of YFP.

Summary A 31-year-old man presented with cryptococcal meningitis (CM) without typical clinical characteristics, but with abnormal walking, difficult leg lifting and frequent falling. He was admitted to a hospital in Beijing for two months and then transferred to Peking Union Medical College Hospital. After multiple tests failed to identify the pathogen, single-cell sequencing (scS) was used to test the cerebrospinal fluid (CSF). Comparing the sequence obtained from single-cell sequencing with the reference database, it was found that the infection was caused by Cryptococcus gattii sensu stricto (AFLP4/VGI genotype). Cryptococcus is difficult to cultivate from complex body fluids. The etiological agent of this patient was identified and the patient was treated. This case is the first case in which scS was used to detect and identify fungal pathogen after conventional testing failed to identify the cause of the disease. This report demonstrates that the scS approach can be used to generate fungal genome sequences directly from the CSF of a CM patient. The scS technology could become a powerful tool to precise detect microscopically visible but uncultured pathogens in clinical samples.

1. Several animal species are known to distinguish between their own eggs and eggs of unrelated conspecifics. However, the cues involved in this discrimination are often unknown. These cues were studied using the predatory mite Gynaeseius liturivorus Ehara.2. Adult females of these predatory mites oviposit in clusters and avoid oviposition close to eggs laid by other females, resulting in reduced cannibalism between offspring. Because predatory mites are blind, it was tested whether volatiles of eggs were used as a cue for egg recognition.3. Adult female predatory mites were offered volatile cues of their own eggs and of unrelated conspecific eggs, and females were prevented from contacting the eggs. Predatory mites oviposited closer to their own eggs than to unrelated eggs. This preference was observed even when one own and one unrelated egg were offered as a volatile source.4. These results suggest that adult female predatory mites can determine kinship using volatiles released from the eggs.

Because plant phenotypes can change in response to attacks by herbivores in highly variable ways, the distribution of herbivores depends on the occurrence of other herbivore species on the same plant. We carried out a field study to evaluate the co-occurrence of three coconut pests, the mitesAceria guerreronis(Acari: Eriophyidae),Steneotarsonemus concavuscutum(Acari: Tarsonemidae) and the mothAtheloca bondari(Lepidoptera: Pyralidae). The eriophyid miteAc. guerreronisis the most important coconut pest around the world, whereasS. concavuscutumandAt. bondariare economically important only in some areas along the Brazilian coast. A previous study suggested that the necrosis caused byAc. guerreronisfacilitates the infestation ofAt. bondarilarvae. Because all three species infest the area under the perianths on coconuts andS. concavuscutumalso causes necrosis that could facilitateAt. bondari, we evaluated the co-occurrence of all three species. We found that the occurrence ofAt. bondariwas positively associated withAc. guerreronis, but negatively associated withS. concavuscutum. In addition, the two mite species showed negative co-occurrence.Atheloca bondariwas found on nuts of all ages, but more on nuts that had fallen than on those on the trees, suggesting that nuts infested byAt. bondaritend to fall more frequently. We discuss the status ofAt. bondarias a pest and discuss experiments to test the causes of these co-occurrence patterns.

Few studies have tested how plant quality and the presence of competitors interact in determining how herbivores choose between different leaves within a plant. We investigated this in two herbivorous spider mites sharing tomato plants: Tetranychus urticae, which generally induces plant defenses, and Tetranychus evansi, which suppresses them, creating asymmetrical effects on coinfesting competitors. On uninfested plants, both herbivore species preferred young leaves, coinciding with increased mite performance. On plants with heterospecifics, the mites did not prefer leaves on which they had a better performance. In particular, T. urticae avoided leaves infested with T. evansi, which is in agreement with T. urticae being outcompeted by T. evansi. In contrast, T. evansi did not avoid leaves with the other species, but distributed itself evenly over plants infested with heterospecifics. We hypothesize that this behavior of T. evansi may prevent further spread of T. urticae over the shared plant. Our results indicate that leaf age determines within‐plant distribution of herbivores only in absence of competitors. Moreover, they show that this distribution depends on the order of arrival of competitors and on their effects on each other, with herbivores showing differences in behavior within the plant as a possible response to the outcome of those interactions., Within‐plant herbivore distribution is likely to affect species interactions. Here, we show that, in absence of competitors, herbivorous spider mites settle on tomato leaves that maximize their oviposition. However, in presence of another species, they choose plant strata that minimize competition.

genodive version 3.0 is a user‐friendly program for the analysis of population genetic data. This version presents a major update from the previous version and now offers a wide spectrum of different types of analyses. genodive has an intuitive graphical user interface that allows direct manipulation of the data through transformation, imputation of missing data, and exclusion and inclusion of individuals, population and/or loci. Furthermore, genodive seamlessly supports 15 different file formats for importing or exporting data from or to other programs. One major feature of genodive is that it supports both diploid and polyploid data, up to octaploidy (2n = 8x) for some analyses, but up to hexadecaploidy (2n = 16x) for other analyses. The different types of analyses offered by genodive include multiple statistics for estimating population differentiation (φ ST, F ST, FʹST, G ST, GʹST, GʹʹST, D est, R ST, ρ), analysis of molecular variance‐based K‐means clustering, Hardy–Weinberg equilibrium, hybrid index, population assignment, clone assignment, Mantel test, Spatial Autocorrelation, 23 ways of calculating genetic distances, and both principal components and principal coordinates analyses. A unique feature of genodive is that it can also open data sets with nongenetic variables, for example environmental data or geographical coordinates that can be included in the analysis. In addition, genodive makes it possible to run several external programs (lfmm, structure, instruct and vegan) directly from its own user interface, avoiding the need for data reformatting and use of the command line. genodive is available for computers running Mac OS X 10.7 or higher and can be downloaded freely from: http://www.patrickmeirmans.com/software., see also the Perspective by Amanda S. Ackiss and Francisco Balao

BACKGROUND Geographic variation in male response to sex pheromone lures has been studied in the field in a number of moth species. However, only a few studies have investigated geographic variation in female calling and sex pheromone under field conditions. For an effective field implementation of sex pheromone lures, it is essential to know the local sex pheromone blend and local timing of sexual communication. We investigated the level and extent of geographic variation in the sexual communication of the important agricultural pest Helicoverpa armigera (Lepidoptera, Noctuidae) in three continents. RESULTS We found there is no genetic variation in the calling behavior of H. armigera. In the female sex pheromone, we found more between‐population variation than within‐population variation. In male response experiments, we found geographic variation as well. Strikingly, when adding the antagonistic compound Z11‐16:OAc to the pheromone blend of H. armigera, significantly fewer males were caught in Australia and China, but not in Spain. This variation is likely not only due to local environmental conditions, such as photoperiod and temperature, but also to the presence of other closely related species with which communication interference may occur. Conclusion Finding geographic variation in both the female sexual signal and the male response in this pest calls for region‐specific pheromone lures. Our study shows that the analysis of geographic variation in moth female sex pheromones as well as male responses is important for effectively monitoring pest species that occur around the globe. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., In this paper we found geographic variation in the female sex pheromone and the male response of the cotton bollworm, Helicoverpa armigera. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Predatory mites of the Phytoseiidae family are important biological control agents. Many species of this family are omnivores, i.e., besides on prey, they can feed on plant resources such as nectar and pollen. It has been shown that the addition of alternative food for predators to a crop enhances biological control. However, factors such as food availability and quality can also affect interactions such as cannibalism, and thus influence biological control. We investigated the role of quality of the alternative food in the tendency of Amblyseius herbicolus to engage in cannibalism, a common ecological interaction in many phytoseiid mite species. Cannibalism on eggs by A. herbicolus was significantly reduced in the presence of high-quality food (cattail pollen) compared to egg cannibalism without alternative food, whereas this was not the case in the presence of low-quality food (cotton pollen). This suggests that cattail pollen is a high-quality alternative food, not only because it results in increased development and reproduction of predators, but also because it can minimize cannibalism.

Introduction. Given the limited number of candidaemia studies in Iran, the profile of yeast species causing bloodstream infections (BSIs), especially in adults, remains limited. Although biochemical assays are widely used in developing countries, they produce erroneous results, especially for rare yeast species.Aim. We aimed to assess the profile of yeast species causing BSIs and to compare the accuracy of the Vitek 2 system and 21-plex PCR.Methodology. Yeast blood isolates were retrospectively collected from patients recruited from two tertiary care training hospitals in Tehran from 2015 to 2017. Relevant clinical data were mined. Identification was performed by automated Vitek 2, 21-plex PCR and sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2).Results. In total, 137 yeast isolates were recovered from 107 patients. The overall all-cause 30-day mortality rate was 47.7 %. Fluconazole was the most widely used systemic antifungal. Candida albicans (58/137, 42.3 %), Candida glabrata (30/137, 21.9 %), Candida parapsilosis sensu stricto (23/137, 16.8 %), Candida tropicalis (10/137, 7.3 %) and Pichia kudriavzevii (Candida krusei) (4/137, 2.9 %) constituted almost 90 % of the isolates and 10 % of the species detected were rare yeast species (12/137; 8.7 %). The 21-plex PCR method correctly identified 97.1 % of the isolates, a higher percentage than the Vitek 2 showed (87.6 %).Conclusion. C. albicans was the main cause of yeast-derived fungaemia in this study. Future prospective studies are warranted to closely monitor the epidemiological landscape of yeast species causing BSIs in Iran. The superiority of 21-plex PCR over automated Vitek 2 indicates its potential clinical utility as an alternative identification tool use in developing countries.

Plant defense suppression is an offensive strategy of herbivores, in which they manipulate plant physiological processes to increase their performance. Paradoxically, defense suppression does not always benefit the defense‐suppressing herbivores, because lowered plant defenses can also enhance the performance of competing herbivores and can expose herbivores to increased predation. Suppression of plant defense may therefore entail considerable ecological costs depending on the presence of competitors and natural enemies in a community. Hence, we hypothesize that the optimal magnitude of suppression differs among locations. To investigate this, we studied defense suppression across populations of Tetranychus evansi spider mites, a herbivore from South America that is an invasive pest of solanaceous plants including cultivated tomato, Solanum lycopersicum, in other parts of the world. We measured the level of expression of defense marker genes in tomato plants after infestation with mites from eleven different T. evansi populations. These populations were chosen across a range of native (South American) and non‐native (other continents) environments and from different host plant species. We found significant variation at three out of four defense marker genes, demonstrating that T. evansi populations suppress jasmonic acid‐ and salicylic acid‐dependent plant signaling pathways to varying degrees. While we found no indication that this variation in defense suppression was explained by differences in host plant species, invasive populations tended to suppress plant defense to a smaller extent than native populations. This may reflect either the genetic lineage of T. evansi—as all invasive populations we studied belong to one linage and both native populations to another—or the absence of specialized natural enemies in invasive T. evansi populations., Suppression of plant defenses by herbivores promotes herbivore performance, but may also increase competition and predation. We hypothesize that biotic interactions with competitors and natural enemies shape the costs and benefits of defense suppression, and found significant variation in the magnitude of defense suppression among eleven populations of the defense‐suppressing spider mite Tetranychus evansi, ranging from Brazil to Japan. Invasive populations tended to suppress plant defense to a smaller extent than native populations, and we speculate that this may reflect the absence of specialized natural enemies in invasive T. evansi populations.

1. Fully mycoheterotrophic plants are thought to obtain carbon exclusively from their root-associated fungal partners. The general enrichment of these plants in the heavy isotopes 13C and 15N suggests that fungi are the main nutrient source for these plants. Yet, the majority of studies have targeted mycoheterotrophic plants associated with ectomycorrhizal, orchid mycorrhizal and saprotrophic fungi, while mycoheterotrophic plants living on arbuscular mycorrhizal fungi remain understudied.2. Here, we sampled 13 species of arbuscular mycorrhizal fully mycoheterotrophic plants from five families and co-occurring autotrophic reference plants growing in forests of tropical South America, tropical South East Asia and temperate Australasia. We measured stable isotope natural abundances (δ13C, δ15N, δ2H and δ18O), determined total nitrogen concentrations and used high-throughput DNA sequencing to characterize the arbuscular mycorrhizal fungal communities associated with the sampled mycoheterotrophic plants.3. We observed a general enrichment in 13C and 15N isotopes across mycoheterotrophic plant families and geographic regions. We confirm cases where no 15N enrichment is present, but we show that in general arbuscular mycoheterotrophic plants are enriched in 15N. Moreover, we demonstrate for the first time that these plants are significantly enriched in 2H but not in 18O in relation to their autotrophic references. The fungal communities targeted by the mycoheterotrophs mainly consist of Glomeraceae and show strong association with the isotopic signatures and geographic origin of the plants.4. Synthesis. Our findings enlarge the limited knowledge on the multi-element stable isotopic signatures of mycoheterotrophic plants living on arbuscular mycorrhizal fungi. We show that these plants are enriched in 13C and 2H as expected due to their mycoheterotrophic nutrition, and that in general they are also enriched in 15N, despite some exceptions. Variation in stable isotope signatures is likely influenced by plant taxonomy, geography and fungal community composition.

To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Here, we focused on the morph-linked reproductive costs of secretion of the abdominal fluid and quantified the proportion of phenotypic and genetic variation in it. We hypothesized that, if yellow males pay higher reproductive costs for their more effective aposematic display, the subsequent higher mating success of white males could offer one explanation for the maintenance of the polymorphism. We first found that the heritable variation in the quantity of abdominal secretion was very low (h2 = 0.006) and the quantity of defensive secretion was not dependent on the male morph. Second, deploying the abdominal defensive secretion decreased the reproductive output of both color morphs equally. This suggests that potential costs of pigment production and chemical defense against invertebrates are not linked in A. plantaginis. Furthermore, our results indicate that environmentally induced variation in chemical defense can alter an individual’s fitness significantly., How much does it cost to defend against predators? A lot if you are a male wood tiger moth as deploying their defensive secretion decreases their reproductive success. When threatened, these aposematic moths produce defensive secretions from their abdomen, which are targeted specifically against invertebrate predators. However, this invertebrate-specific defense does not come without costs: deploying the defensive secretion only once decreases the reproductive success of males.

Insects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunting tactics, in particular between vertebrate and invertebrate predators, it is not always clear whether defences, such as chemical defences, that are effective against one group will be so against another. Despite this, the majority of research to date has focused on the role of a single predator species when considering the evolution of defended prey. Here we test the effectiveness of the chemical defences of the wood tiger moth, a species previously shown to have defensive chemicals targeted towards ants, against a common invertebrate predator: spiders. We presented both live moths and artificial prey containing their defensive fluids to female Trichonephila senegalensis and recorded their reactions. We found that neither of the moth’s two defensive fluids were able to repel the spiders, and confirmed that methoxypyrazines, a major component of the defences of both the wood tiger moth and many insect species, are ineffective against web-building spiders. Our results highlight the variability between predator taxa in their susceptibility to chemical defences, which can in part explain the vast variation in these chemicals seen in insects, and the existence of multiple defences in a single species.

Agroecology is the study of linkages in agricultural systems and it derives from the need to understand and restore natural connections and ecological complexity to control insect and other pest populations. The present special issue addresses a rich variety of agroecosystems spanning the globe, involving the roles of a range of insects on a great many crops. The overview will further improve our understanding of the complex ecology of the players and the ecological complexity of the crop systems.

In social-living animals, interactions between groups are frequently agonistic, but they can also be tolerant and even cooperative. Intergroup tolerance and cooperation are regarded as a crucial step in the formation of highly structured multilevel societies. Behavioral ecological theory suggests that intergroup tolerance and cooperation can emerge either when the costs of hostility outweigh the benefits of exclusive resource access or when both groups gain fitness benefits through their interactions. However, the factors promoting intergroup tolerance are still unclear due to the paucity of data on intergroup interactions in tolerant species. Here, we examine how social and ecological factors affect the onset and termination of intercommunity encounters in two neighboring communities of wild bonobos, a species exhibiting flexible patterns of intergroup interactions, at Kokolopori Bonobo Reserve, Democratic Republic of the Congo. We recorded the timing and location of intercommunity encounters and measured fruit abundance and distribution, groups’ social characteristics, and space-use dynamics over a 19-month period. We found that intercommunity tolerance was facilitated by a decrease in feeding competition, with high fruit abundance increasing the likelihood of communities to encounter, and high clumpiness of fruit patches increasing the probability to terminate encounters likely due to increased contest. In addition, the possibility for extra-community mating, as well as the potential benefits of more efficient foraging in less familiar areas, reduced the probability that the communities terminated encounters. By investigating the factors involved in shaping relationships across groups, this study contributes to our understanding of how animal sociality can extend beyond the group level.

Background Under strong sexual selection, certain species evolve distinct intrasexual, alternative reproductive tactics (ARTs). In many cases, ARTs can be viewed as environmentally-cued threshold traits, such that ARTs coexist if their relative fitness alternates over the environmental cue gradient. Surprisingly, the chemical ecology of ARTs has been underexplored in this context. To our knowledge, no prior study has directly quantified pheromone production for ARTs in a male-polymorphic species. Here, we used the bulb mite—in which males are either armed fighters that kill conspecifics, or unarmed scramblers (which have occasionally been observed to induce mating behavior in other males)—as a model system to gain insight into the role of pheromones in the evolutionary maintenance of ARTs. Given that scramblers forgo investment into weaponry, we tested whether scramblers produce higher quantities of the putative female sex-pheromone α-acaridial than fighters, which would improve the fitness of the scrambler phenotype through female mimicry by allowing avoidance of aggression from competitors. To this end, we sampled mites from a rich and a poor nutritional environment and quantified their production of α-acaridial through gas chromatography analysis. Results We found a positive relationship between pheromone production and body size, but males exhibited a steeper slope in pheromone production with increasing size than females. Females exhibited a higher average pheromone production than males. We found no significant difference in slope of pheromone production over body size between fighters and scramblers. However, scramblers reached larger body sizes and higher pheromone production than fighters, providing some evidence for a potential female mimic strategy adopted by large scramblers. Pheromone production was significantly higher in mites from the rich nutritional environment than the poor environment. Conclusion Further elucidation of pheromone functionality in bulb mites, and additional inter- and intrasexual comparisons of pheromone profiles are needed to determine if the observed intersexual and intrasexual differences in pheromone production are adaptive, if they are a by-product of allometric scaling, or diet-mediated pheromone production under weak selection. We argue chemical ecology offers a novel perspective for research on ARTs and other complex life-history traits.

Sexual selection is a potent evolutionary force and was proposed by Darwin because natural selection alone could not explain the evolution of exaggerated sexual signals, like colourful ornaments in birds. Sexual signals for mate choice are commonly investigated with the assumption that one sex is the signaller while the other sex chooses. However, both sexes can be signallers and choosers. When sexual signallers are choosers too, mutual mate choice arises and increases the number and interactions of selection pressures. Mutual mate choice may thus alter the resulting selection pressures on sexual signals. Therefore, it is important to understand the role of both sexes in sexual communication. While females of the tobacco budworm Chloridea (formerly Heliothis) virescens (Lepidoptera: Noctuidae) attract males via a long-range sex pheromone, males also emit a pheromone from elaborate structures, called hairpencils, at close range. Females use the male hairpencil pheromone for species recognition but whether these chemicals are used by the female to discriminately assess males of different quality was unclear. This thesis researched mutual mate choice by providing evidence for female mate choice in a noctuid moth and determined the male signal underlying female mate choice. In conclusion, mutual mate choice in C. virescens exists, but this mutual choice is based on different types of signals: while females attract males via a sex pheromone, males signal their attractiveness not through the biosynthetically related male hairpencil pheromone, but through another signal that conveys information about male size.

All species of great ape construct nests for periods of sleep or rest. The aim of this thesis was to explore the cognitive and cultural aspects of nest building behaviour to improve our understanding of the implications of the behaviour to the daily lives of orangutans and to the evolution of intelligence and material culture in hominids. Data were collected principally at Suaq Balimbing, Sumatra with comparative data from the ecologically similar but genetically distinct Sabangau, Kalimantan. We observed nest building events, revisited nests to collect empirical data and systematically deconstructed nests at both sites to compare nest structures and to identify nest function and describe the ontogeny of the behaviour. We found distinct functions for day and night nests, identified preferences according to the age-sex class of the individuals and present evidence that species preferences are cultural and not a product of habitat availability. Orangutans at Suaq provide evidence of innovations in nest architecture but commonalities between the sites and with chimpanzees in Africa suggest a conserved template exists for nests in the hominid clade. In Sumatra, the ontogeny of nest building took over seven years with practice of the more complex elements extending beyond independence. Simple day nests are mastered around the first birthday, but exploration and practice of night nests takes place around the onset of weaning. This thesis has shown that culture pervades nest building and that it requires complex hierarchical cognition providing compelling evidence that the last common ancestor was capable of complex technical intelligence.

Organismal development is generally sensitive to environmental cues and perturbations. One common mode of such plasticity is adaptive condition-dependence, where development responds adaptively to cues from the developing phenotype itself, mitigating current problems and anticipating future challenges. Such adaptive condition-dependent plasticity can be a subtle buffering mechanism that simply canalizes development in the face of environmental variation. However, when individuals differing in condition experience distinct sets of ecological affordances, adaptive condition-dependent plasticity can result in spectacular phenotypic variation. A prominent example of this is heightened condition-dependent variation in arthropod ornaments and armaments, in which condition-dependence regularly takes the form of polyphenism with discrete ‘minor’ and ‘major’ morphs. In this dissertation, I discuss the evolution of condition-dependent polyphenism in arthropod secondary sexual traits. I first review the evidence for ecological mechanisms causing selection for condition-dependent polyphenism in arthropods. I then use the male-polyphenic acarid mite Rhizoglyphus robini as a case study to investigate how the ecological environment affords different opportunities to poorly-growing and well-growing males, and how polyphenic development of secondary sexual traits (enlarged and modified legs used as weaponry in intrasexual fights, generally absent in poorly growing males) responds to body size and growth rate. I present evidence that relatively small males are less likely to win fights and benefit less from weaponry than larger males; polyphenism thus prepares for an alternative mating tactic. Additionally, slowly growing males accelerate their life history pace by not developing weaponry; polyphenism thus protects maturation age against variation in somatic growth. Understanding how development adaptively maintains the capacity to either canalize or amplify phenotypic variation through adaptive condition-dependence is key to understanding evolutionary shifts in form and function, as phenotypic variation is the raw material for evolution by natural selection.

Yeasts, usually defined as unicellular fungi, occur in various fungal lineages. Hence, they are not a taxonomic unit, but rather represent a fungal lifestyle shared by several unrelated lineages. Although the discovery of new yeast species occurs at an increasing speed, at the current rate it will likely take hundreds of years, if ever, before they will all be documented. Many parts of the earth, including many threatened habitats, remain unsampled for yeasts and many others are only superficially studied. Cold habitats, such as glaciers, are home to a specific community of cold-adapted yeasts, and, hence, there is some urgency to study such environments at locations where they might disappear soon due to anthropogenic climate change. The same is true for yeast communities in various natural forests that are impacted by deforestation and forest conversion. Many countries of the so-called Global South have not been sampled for yeasts, despite their economic promise. However, extensive research activity in Asia, especially China, has yielded many taxonomic novelties. Comparative genomics studies have demonstrated the presence of yeast species with a hybrid origin, many of them isolated from clinical or industrial environments. DNA-metabarcoding studies have demonstrated the prevalence, and in some cases dominance, of yeast species in soils and marine waters worldwide, including some surprising distributions, such as the unexpected and likely common presence of Malassezia yeasts in marine habitats. TG acknowledges support from the Spanish Ministry of Science and Innovation for grant PGC2018-099921-B-I00, cofounded by European Regional Development Fund (ERDF); from the Catalan Research Agency (AGAUR) SGR423; from the European Union’s Horizon 2020 research and innovation program (ERC-2016–724173); from the Gordon and Betty Moore Foundation (Grant # GBMF9742). JG acknowledges support from the Lendület Program (award no. 96049) of the Hungarian Academy of Sciences and the Eötvös Lóránd Research Network. Q-MW was supported by grants No. 31961133020 and No. 31770018 from the National Natural Science Foundation of China (NSFC). ASA and FEB were supported by grant 9343 from the Gordon and Betty Moore Foundation: https://doi.org/10.37807/GBMF9343. "Article signat per 12 autors/es: Teun Boekhout, Anthony S. Amend, Fouad El Baidouri, Toni Gabaldón, József Geml, Moritz Mittelbach, Vincent Robert, Chen Shuhui Tan, Benedetta Turchetti, Duong Vu, Qi-Ming Wang & Andrey Yurkov "

Plastic debris has been accumulating in the marine realm since the start of plastic mass production in the 1950s. Due to the adverse effects on ocean life, the fate of plastics in the marine environment is an increasingly important environmental issue. Microbial degradation, in addition to weathering, has been identified as a potentially relevant breakdown route for marine plastic debris. Although many studies have focused on microbial colonization and the potential role of microorganisms in breaking down marine plastic debris, little is known about fungi-plastic interactions. Marine fungi are a generally understudied group of microorganisms but the ability of terrestrial and lacustrine fungal taxa to metabolize recalcitrant compounds, pollutants, and some plastic types (e.g., lignin, solvents, pesticides, polyaromatic hydrocarbons, polyurethane, and polyethylene) indicates that marine fungi could be important degraders of complex organic matter in the marine realm, too. Indeed, recent studies demonstrated that some fungal strains from the ocean, such as Zalerion maritimum have the ability to degrade polyethylene. This mini-review summarizes the available information on plastic-fungi interactions in marine environments. We address (i) the currently known diversity of fungi colonizing marine plastic debris and provide (ii) an overview of methods applied to investigate the role of fungi in plastic degradation, highlighting their advantages and drawbacks. We also highlight (iii) the underestimated role of fungi as plastic degraders in marine habitats.

Generally, males increase their reproductive success by mating with as many females as possible, whereas females increase their reproductive success by choosing males who provide more direct and indirect benefits. The difference in reproductive strategy between the sexes creates intense competition among males for access to females, therefore males spend much energy and time for competition with rival males for their reproduction. However, if they do not need to engage themselves into male competition and females are in no short supply, how many females can a male mate with and fertilize? We address this question in the two-spotted spider mite, Tetranychus urticae Koch. In this study, we investigated how many females a young, virgin male mated in 3 h, and checked whether the mated females were fertilized. We found that on average males mated with 12-13 females (range: 5-25). As latency to next mating did not change with the number of matings, the males are predicted to engage in even more matings if the mating trial were continued beyond 3 h. Copulation durations decreased with the number of matings and typically after 11 copulations with females any further copulations did not lead to fertilization, suggesting that males continued to mate with females even after sperm depletion. We discuss why spider mite males continue to display mating and copulation behaviour even after their sperm is depleted.

Species of Trichosporon and related genera are widely used in biotechnology and, hence, many species have their genome sequenced. Importantly, yeasts of the genus Trichosporon have been increasingly identified as a cause of life-threatening invasive trichosporonosis (IT) in humans and are associated with an exceptionally high mortality rate. Trichosporon spp. are intrinsically resistant to frontline antifungal agents, which accounts for numerous reports of therapeutic failure when echinocandins are used to treat IT. Moreover, these fungi have low sensitivity to polyenes and azoles and, therefore, are potentially regarded as multidrug-resistant pathogens. However, despite the clinical importance of Trichosporon spp., our understanding of their antifungal resistance mechanisms is quite limited. Furthermore, antifungal susceptibility testing is not standardized, and there is a lack of interpretive epidemiological cut-off values for minimal inhibitory concentrations to distinguish non-wild type Trichosporon isolates. The route of infection remains obscure and detailed clinical and environmental studies are required to determine whether the Trichosporon infections are endogenous or exogenous in nature. Although our knowledge on effective IT treatments is rather limited and future randomized clinical trials are required to identify the best antifungal agent, the current paradigm advocates the use of voriconazole, removal of central venous catheters and recovery from neutropenia.

Prickly lettuce (Lactuca serriola L., Asteraceae), a wild relative of cultivated lettuce, is an autogamous species which greatly expanded throughout Western and Northern Europe during the last 2 centuries. Here, we present a large-scale biogeographic genetic analysis performed on a dataset represented by 2622 individuals from 110 wild European populations. Thirty-two maternally inherited chloroplast RFLP-markers and 10 nuclear microsatellite loci were used. Microsatellites revealed low genetic variation and high inbreeding coefficients within populations, as well as strong genetic differentiation between populations, which was in accordance with the autogamous breeding system. Analysis of molecular variance based clustering indicated the presence of 3 population clusters, which showed strong geographical patterns. One cluster occupied United Kingdom and part of Northern Europe, and characterized populations with a single predominant genotype. The second mostly combined populations from Northern Europe, while the third cluster grouped populations particularly from Southern Europe. Kriging of gene diversity for L. serriola corroborated northwards and westwards spread from Central (Eastern) Europe. Significant lower genetic diversity characterized the newly colonized parts of the range compared to the historical ones, confirming the importance of founder effects. Stronger pattern of isolation by distance was assessed in the newly colonized areas than in the historical areas (Mantel’s r = 0.20). In the newly colonized areas, populations at short geographic distances were genetically more similar than those in the historical areas. Our results corroborate the species’ recent and rapid northward and westward colonization from Eastern Europe, as well as a decrease of genetic diversity in recently established populations.