Solonkin, Igor Andreevich

Solonkin I.A., Zakharova E.Y., Shkurikhin A.O.

Solonkin I.A., Zakharova E.Y., Shkurikhin A.O.

Solonkin I.A., Zakharova E.Y., Shkurikhin A.O.

Patterns of appearance of wing venation abnormalities in the black-veined white Aporia crataegi L. were studied. These abnormalities form four types of bilateral compositions and vary quantitatively in the degree of phenotypic expression. This implies that wing venation abnormalities in A. crataegi may be regarded as stable states of threshold nonmetric traits with hidden quantitative variability, i.e., “phenes.” Different venation abnormalities vary in the pattern of appearance, either showing a trend toward joint occurrence in one individual or occurring independently of each other. Some abnormalities appear mainly asymmetrically, randomly, and independently in different body sides, while others tend to occur symmetrically. Only those abnormalities which appear independently of each other, randomly, and independently in different body sides can be considered random developmental errors and indicators of developmental instability. Such abnormalities were rare, making up less than 20% of the total number.

SOLONKIN I.A., SHKURIKHIN A.O., OSLINA T.S., ZAKHAROVA E.Y.

Zakharova E.Y., Shkurikhin A.O., Solonkin I.A., Oslina T.S.

Patterns of interaction of an oligophagous insect, black-veined white Aporia crataegi L., with host plants in years with a low density of its natural population are analyzed. In years with low A. crataegi population abundance in the south of Sverdlovsk region (Sysertsky district), the species composition of caterpillar host plants gradually decreases from several woody rosaceous species of the genera Padus, Sorbus, Malus, and Crataegus to one species (Padus avium Mill.). It is shown that the mortality rate is higher for fifth-instar caterpillars developing on mountain ash than for those developing on bird cherry. Adult A. crataegi developing on bird cherry are not only larger but also grow faster than those developing on mountain ash, which may be an additional factor responsible for the observed chronographic variation during the emergence of A. crataegi generation in nature.

Zakharova E.Y., Shkurikhin A.O., Oslina T.S., Solonkin I.A.

Shkurikhin A.O., Zakharova E.Y., Oslina T.S., Solonkin I.A.

The correlation between the timing of adult emergence and variation in morphophysiological parameters of males and females has been analyzed in the black-veined white Aporia crataegi L. In 2013 to 2015, black-veined white butterflies were collected from a natural population in the south of Sverdlovsk oblast throughout the emergence period; at the same time, adult insects were reared from pupae in individual cages. Comparison of the field observations in nature and the results of rearing preimaginal stages has shown that the largest adults are the first to emerge, while the smallest are the last to emerge. This pattern holds true both for the parameters varying throughout the adult insect life (body weight and relative abdomen weight) and for the permanent characteristic of the “structural” size (wing area). The influence of protandry and food availability to caterpillars on the variation in the size of adult A. crataegi during the period of generation emergence is discussed.

Solonkin I.А., Zakharova E.Y., Shkurikhin А.О.

Abstract – The work studied the effects of air temperature and precipitation during the post-diapause development of preimaginal stages, as well as wing size, on the occurrence of deviations from normal wing venation in Aporia crataegi. Samples collected from a natural population in the southern Sverdlovsk region from 2013 to 2022 were analyzed. The occurrence of wing venation abnormalities was shown to be depend on weather conditions during the development of larvae and pupae in spring, as well as the size of the adults. Some variants were more frequent in years with cold and rainy springs, while the occurrence of others was not dependent on the weather. Certain wing venation abnormalities were more common in small adults, while others were more common in larger individuals. The results obtained indicate a variable degree of canalization and sensitivity of wing vein development in Aporia crataegi to the effects of environmental factors.

Solonkin I.A., Zakharova E.Y., Shkurikhin A.O.

Whitla R., Hens K., Hogan J., Martin G., Breuker C., Shreeve T.G., Arif S.

AbstractCurrent rates of habitat degradation and climate change are causing unprecedented declines in global biodiversity. Studies on vertebrates highlight how conservation genomics can be effective in identifying and managing threatened populations, but it is unclear how vertebrate‐derived metrics of genomic erosion translate to invertebrates, with their markedly different population sizes and life histories. The Black‐veined White butterfly (Aporia crataegi) was extirpated from Britain in the 1920s. Here, we sequenced historical DNA from 17 specimens collected between 1854 and 1924 to reconstruct demography and compare levels of genomic erosion between extirpated British and extant European mainland populations. We contrast these results using modern samples of the Common Blue butterfly (Polyommatus icarus); a species with relatively stable demographic trends in Great Britain. We provide evidence for bottlenecks in both these species around the period of post‐glacial colonization of the British Isles. Our results reveal different demographic histories and Ne for both species, consistent with their fates in Britain, likely driven by differences in life history, ecology and genome size. Despite a difference, by an order of magnitude, in historical effective population sizes (Ne), reduction in genome‐wide heterozygosity in A. crataegi was comparable to that in P. icarus. Symptomatic of A. crataegi's disappearance were marked increases in runs‐of‐homozygosity (RoH), potentially indicative of recent inbreeding, and accumulation of putatively mildly and weakly deleterious variants. Our results provide a rare glimpse of genomic erosion in a regionally extinct insect and support the potential use of genomic erosion metrics in identifying invertebrate populations or species in decline.

Whitla R., Hens K., Breuker C.J., Shreve T.G., Arif S.

AbstractCurrent rates of habitat degradation and climate change are causing unprecedented declines in global biodiversity. Studies on vertebrates highlight how conservation genomics can be an effective tool to identify and manage threatened populations, but it is unclear how vertebrate derived metrics of genomic erosion translate to invertebrate species, with their markedly different population sizes and life histories. The Black-veined White butterfly (Aporia crataegi)was extirpated from Britain in the 1920s. Here, we sequenced historical DNA from 17 museum specimens collected between 1854-1924 to reconstruct demography and determine levels of genomic erosion in the species as it approached extirpation. We compare these results to those from the Common Blue butterfly (Polyommatus icarus); a species with relatively stable demographic trends in Great Britain. We provide evidence for bottlenecks in both these species around the period of post-glacial colonisation of the British Isles. Our results reveal different demographic histories andNefor both species, consistent with their fates in Britain, likely driven by differences in life history, ecology, genome lengths and body size. Despite a difference, by an order of magnitude, in historical effective population sizes (Ne), reduction in genetic diversity inA. crataegiwas comparable to that inP. icarus. Symptomatic ofA. crataegi’s disappearance were marked increases in runs-of-homozygosity (RoH), consistent with recent inbreeding, and accumulation of putatively mildly and weakly deleterious variants. Our results support the idea that metrics of inbreeding and accumulation of deleterious mutations could be more informative markers of population or species in decline.

Gailis J., Jakobija I., Jakobsone E., Ozoliņa-Pole L., Rancāne R., Salmane I.

Abstract The objective of this research was to study potential pests of Japanese quince (Chaenomeles japonica) plantations in Latvia. Studies were carried out in eight plantations during 2017–2019. Major pests that would regularly cause significant yield losses for this plant were not observed. Black-veined white (Aporia crataegi) was considered a local pest, mass outbreaks of which can occur in individual plantations and cause significant losses of plant foliage. Four species were considered minor pests: garden chafer (Phyllopertha horticola), yellow-banded weevil (Chlorophanus viridis), silver-green weevil (Phyllobius argentatus) and copse snail (Arianta arbustorum); they are also pests of plant foliage. The European red spider mite (Panonychus ulmi) was not considered as a pest of Japanese quince. A small population was observed in summers only in one plantation, which was located next to a heavily infested orchard. Overwintering eggs were not found on the plants in any year, and we concluded that the species was an accidental immigrant in this plantation. No aphid (Aphididae) colonies were observed on the quince plants. Monitoring and evaluation of potential harmfulness of four tortrix moths – large fruit-tree tortrix (Archips podana), rose tortrix (Archips rosana), codling moth (Cydia pomonella) and holly tortrix (Rhopobota naevana) – was done. It was concluded that rose tortrix is a minor fruit pest, but the other three species were not yet considered pests of Japanese quince. Significant pests of quince flowers and fruits were not detected in our study.

Shkurikhin A.O., Zakharova E.Y., Vorobeichik E.L.

We have tested the hypotheses that the satyrs Aphantopus hyperantus and Coenonympha arcania accumulate metals in higher concentrations near the Middle Ural Copper Smelter than in the background area and that metal accumulation in the body of adult individuals is negatively correlated with the wing length but positively correlated with the fluctuating asymmetry of the wing length. We measured the length of the forewing and individual concentrations of Zn, Cu, Pb, and Cd in the body of adults captured at different distances from the copper smelter (Revda city, Russia). The metal content reaches very high levels, with Zn concentrations being higher than Cu and Pb concentrations by an order of magnitude and Cd concentration by two orders of magnitude. In both species, metal accumulation is higher in males than in females. Maximum concentrations of Zn, Cu, and Cd have been recorded near the smelter. The wing length either did not differ between the sites or was higher near the smelter. The statistically significant negative relationship between Cu concentrations and the wing length has been recorded only for females of one of the species (A. hyperantus). In both species, the fluctuating asymmetry of the wing length did not differ between samples from different sites and did not depend on metal concentrations at the individual level.

Shkurikhin A.O., Zakharova E.Y., Vorobeichik E.L.

We tested the hypotheses that near a copper smelter, marigolds Aphantopus hyperantus and Coenonympha arcania accumulate metals in higher concentrations compared to the background territory and that the accumulation of metals in the body of adults negatively correlates with wing length, but positively with fluctuating asymmetry of wing length. We measured the length of the forewing and individual concentrations of Zn, Cu, Pb and Cd in the body of adults captured at different distances from the Sredneuralsk copper smelter (Revda, Russia). The metal content reaches very high levels, with Zn concentrations higher than Cu and Pb concentrations by an order of magnitude, and Cd concentrations by two orders of magnitude. In both species, males accumulate metals significantly more than females. The maximum concentrations of Zn, Cu and Cd were found near the plant. Wing length either did not differ between sites or was higher near the plant. Only for females of one of the species (A. hyperantus) a statistically significant negative relationship was found between Cu concentrations and wing size. In both species, fluctuating wing size asymmetry did not differ between sites and was not affected by metal concentrations at the individual level.

Rhainds M., Delisle J., Boulanger Y., Labrecque A.

The incidence and causality of inverse size-dependent phenology was investigated for spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), in part due to large sample size [>22000 feral females with known body size (wing area) and timing of emergence/occurrence]. Data collected in three Canadian provinces (New Brunswick, Nova Scotia, Quebec) between 1976 and 2019 included a wide array of sampling procedures grouped along gradients of reproductive classes. (1) For resident females of local origin (collected as pupae and allowed to emerge in the laboratory), body size declined over time at seven of seven sites, indicative of inverse size-dependent timing of emergence. (2) Females foraging on trees (collected by fogging host trees or with sweep nets) exhibited declines in body size over time at five of five sites. (3) For behaviorally active females collected at traps (malaise, light, and canopy traps), inverse size-dependent phenology of flight was observed at 20 of 23 combination of trap types/sites; partition of variance indicated limited variation in body size as a function of trap type, thus all inflight females were pooled in subsequent analyses. (4) In contrast to other sampling procedures, dead females collected on drop trays exhibited size-dependent timing of mortality at only one of five sites. The manuscript includes first body size measurements of migrant females captured in the troposphere with a kite balloon; as with other sampling procedures, body size decreased during the interval of sampling. Ongoing studies combining measurements of body size and dry weight of females (wing load) aim at inferring consequences of inverse size-dependent phenology on reproduction and migration of budworms, including linkages with population dynamics.

Junker R.R., Albrecht J., Becker M., Keuth R., Farwig N., Schleuning M.

The framework of the plant economics spectrum advanced our understanding of plant ecology and proved as a unifying concept across plant taxonomy, growth forms and biomes. Similar approaches for animals mostly focus on linking life-history and metabolic theories, but not on their application in ecosystem research. To fill this gap, we propose the animal economics spectrum (AES) based on broadly available traits that describe organismal size, biological times and rates. To exemplify the feasibility and general usefulness of constructing the AES, we compiled data on adult and offspring body mass, life span, age at first reproduction, reproductive and metabolic rate of 98 terrestrial taxa from seven selected animal classes and mapped these taxa into an exemplary quantitative trait space. The AES consists of two principal axes related to reproductive strategies and the pace of life; both axes are linked by animal metabolism. The AES thus closely mirrors seminal ideas on fundamental life-history strategies and more recent discoveries and developments in the fields of life-history and metabolic theories. Furthermore, we find associations between the positions of animals within the AES and taxonomy, thermoregulation and body plan. The AES shows that key dimensions describing different ecological strategies of animals can be depicted with functional traits that are relatively easily accessible for a broad spectrum of animal taxa. We suggest future steps towards an application of the AES in ecosystem research aiming at the understanding of ecological processes and ecosystem functions. Additionally, we urge for databases that compile comparable functional traits for a large proportion of animals, but also for further groups of organisms with the ultimate goal to map the economics spectrum of life. The framework of the AES will be relevant for understanding ecological processes across animal taxa at species, community and ecosystem levels. We further discuss how it can facilitate predictions on how the functional composition and diversity of animal communities can be affected by global change. Read the free Plain Language Summary for this article on the Journal blog.

SOLONKIN I.A., SHKURIKHIN A.O., OSLINA T.S., ZAKHAROVA E.Y.

Zakharova E.Y., Shkurikhin A.O., Solonkin I.A., Oslina T.S.

Patterns of interaction of an oligophagous insect, black-veined white Aporia crataegi L., with host plants in years with a low density of its natural population are analyzed. In years with low A. crataegi population abundance in the south of Sverdlovsk region (Sysertsky district), the species composition of caterpillar host plants gradually decreases from several woody rosaceous species of the genera Padus, Sorbus, Malus, and Crataegus to one species (Padus avium Mill.). It is shown that the mortality rate is higher for fifth-instar caterpillars developing on mountain ash than for those developing on bird cherry. Adult A. crataegi developing on bird cherry are not only larger but also grow faster than those developing on mountain ash, which may be an additional factor responsible for the observed chronographic variation during the emergence of A. crataegi generation in nature.

Oliveira M.M., Nogueira Alves A., Koyama T., Shingleton A., Mirth C.K.

Animals develop in unpredictable, variable environments. In response to environmental change, some aspects of development adjust to generate plastic phenotypes. Other aspects of development, however, are buffered against environmental change to produce robust phenotypes. How organ development is coordinated to accommodate both plastic and robust developmental responses is poorly understood. Here, we demonstrate that the steroid hormone ecdysone coordinates both plasticity of organ size and robustness of organ pattern in the developing wings of the fruit fly Drosophila melanogaster. Using fed and starved larvae that lack prothoracic glands, which synthesize ecdysone, we show that nutrition regulates growth both via ecdysone and via an ecdysone-independent mechanism, while nutrition regulates patterning only via ecdysone. We then demonstrate that growth shows a graded response to ecdysone concentration, while patterning shows a threshold response. Collectively, these data support a model where nutritionally regulated ecdysone fluctuations confer plasticity by regulating disc growth in response to basal ecdysone levels and confer robustness by initiating patterning only once ecdysone peaks exceed a threshold concentration. This could represent a generalizable mechanism through which hormones coordinate plastic growth with robust patterning in the face of environmental change.

Solonkin I.A., Zakharova E.Y., Shkurikhin A.O.

Patterns of appearance of wing venation abnormalities in the black-veined white Aporia crataegi L. were studied. These abnormalities form four types of bilateral compositions and vary quantitatively in the degree of phenotypic expression. This implies that wing venation abnormalities in A. crataegi may be regarded as stable states of threshold nonmetric traits with hidden quantitative variability, i.e., “phenes.” Different venation abnormalities vary in the pattern of appearance, either showing a trend toward joint occurrence in one individual or occurring independently of each other. Some abnormalities appear mainly asymmetrically, randomly, and independently in different body sides, while others tend to occur symmetrically. Only those abnormalities which appear independently of each other, randomly, and independently in different body sides can be considered random developmental errors and indicators of developmental instability. Such abnormalities were rare, making up less than 20% of the total number.

Richard G., Jaquiéry J., Le Trionnaire G.

Many insect species display a remarkable ability to produce discrete phenotypes in response to changes in environmental conditions. Such phenotypic plasticity is referred to as polyphenism. Seasonal, dispersal and caste polyphenisms correspond to the most-studied examples that are environmentally-induced in insects. Cues that induce such dramatic phenotypic changes are very diverse, ranging from seasonal cues, habitat quality changes or differential larval nutrition. Once these signals are perceived, they are transduced by the neuroendocrine system towards their target tissues where gene expression reprogramming underlying phenotypic changes occur. Epigenetic mechanisms are key regulators that allow for genome expression plasticity associated with such developmental switches. These mechanisms include DNA methylation, chromatin remodelling and histone post-transcriptional modifications (PTMs) as well as non-coding RNAs and have been studied to various extents in insect polyphenism. Differential patterns of DNA methylation between phenotypes are usually correlated with changes in gene expression and alternative splicing events, especially in the cases of dispersal and caste polyphenism. Combinatorial patterns of histone PTMs provide phenotype-specific epigenomic landscape associated with the expression of specific transcriptional programs, as revealed during caste determination in honeybees and ants. Alternative phenotypes are also usually associated with specific non-coding RNA profiles. This review will provide a summary of the current knowledge of the epigenetic changes associated with polyphenism in insects and highlights the potential for these mechanisms to be key regulators of developmental transitions triggered by environmental cues.

SOLONKIN I.A., SHKURIKHIN A.O., OSLINA T.S., ZAKHAROVA E.Y.

Mirth C.K., Saunders T.E., Amourda C.

All organisms are exposed to changes in their environment throughout their life cycle. When confronted with these changes, they adjust their development and physiology to ensure that they can produce the functional structures necessary for survival and reproduction. While some traits are remarkably invariant, or robust, across environmental conditions, others show high degrees of variation, known as plasticity. Generally, developmental processes that establish cell identity are thought to be robust to environmental perturbation, while those relating to body and organ growth show greater degrees of plasticity. However, examples of plastic patterning and robust organ growth demonstrate that this is not a hard-and-fast rule.In this review, we explore how the developmental context and the gene regulatory mechanisms underlying trait formation determine the impacts of the environment on development in insects. Furthermore, we outline future issues that need to be resolved to understand how the structure of signaling networks defines whether a trait displays plasticity or robustness.

Zakharova E.Y., Shkurikhin A.O., Solonkin I.A., Oslina T.S.

Patterns of interaction of an oligophagous insect, black-veined white Aporia crataegi L., with host plants in years with a low density of its natural population are analyzed. In years with low A. crataegi population abundance in the south of Sverdlovsk region (Sysertsky district), the species composition of caterpillar host plants gradually decreases from several woody rosaceous species of the genera Padus, Sorbus, Malus, and Crataegus to one species (Padus avium Mill.). It is shown that the mortality rate is higher for fifth-instar caterpillars developing on mountain ash than for those developing on bird cherry. Adult A. crataegi developing on bird cherry are not only larger but also grow faster than those developing on mountain ash, which may be an additional factor responsible for the observed chronographic variation during the emergence of A. crataegi generation in nature.

Chauhan N., Shrivastava N.K., Agrawal N., Shakarad M.N.

‘Developmental robustness’ is the ability of biological systems to maintain a stable phenotype despite genetic, environmental or physiological perturbations. In holometabolous insects, accurate patterning and development is guaranteed by alignment of final gene expression patterns in tissues at specific developmental stage such as molting and pupariation, irrespective of individual rate of development. In the present study, we used faster developing Drosophila melanogaster populations that show reduction of ~22% in egg to adult development time. Flies from the faster developing population exhibit phenotype constancy, although significantly small in size. The reduction in development time in faster developing flies is possibly due to coordination between higher ecdysteroid release and higher expression of developmental genes. The two together might be ensuring appropriate pattern formation and early exit at each development stage in the populations selected for faster pre-adult development compared to their ancestral controls. We report that apart from plasticity in the rate of pattern progression, alteration in the level of gene expression may be responsible for pattern integrity even under reduced development time. • Drosophila melanogaster populations selected for faster development emerge as functional adults in just 7 and half days. • The selected flies are significantly smaller than control flies, yet show no phenotypic abnormalities. • Small yet normal phenotype suggests normal tissue and organ patterning. • Increased ecdysone levels during entire third larval instar ensures completion of stage specific growth within the available short time. • Pattern stability may be maintained by higher intensity of Wg and downstream Ac and Ct in wing imaginal discs.

Rhainds M.

Abstract Reproduction in female spruce budworms, Choristoneura fumiferana, entails sedentary oviposition early in life (gravid females with their heavy abdomen full of eggs are unable to sustain flight), followed by short- and long-range dispersal by females that have laid a portion of their eggs. Body size measurements (wing surface area and dry weight) of gravid females, spent females at death (after all eggs are laid), and inflight females captured at light traps were collected at one location (forest stands near Fredericton in New Brunswick) over multiple years, from the outbreak stage (1976–1979: peak budworm abundance) to late declining phase with collapsing populations (1988–1989, following near two-fold magnitude of decline in adult density after 1987). For both demographic phases, females rarely flew until having laid at least 40% of their eggs, in contradiction to the hypothesis that females in defoliated forest stands can fly upon emergence due to their light-weight abdomen. As expected, the weight and fecundity of females in 1988–1989 was significantly lower than early on; in terms of body size (wing surface area), however, females were larger in late outbreak phase. These trends suggest that females have evolved morphological adaptation to further dispersal from deteriorated habitats.

Gely C., Laurance S.G., Stork N.E.

Increased frequency and severity of drought, as a result of climate change, is expected to drive critical changes in plant-insect interactions that may elevate rates of tree mortality. The mechanisms that link water stress in plants to insect performance are not well understood. Here, we build on previous reviews and develop a framework that incorporates the severity and longevity of drought and captures the plant physiological adjustments that follow moderate and severe drought. Using this framework, we investigate in greater depth how insect performance responds to increasing drought severity for: (i) different feeding guilds; (ii) flush feeders and senescence feeders; (iii) specialist and generalist insect herbivores; and (iv) temperate versus tropical forest communities. We outline how intermittent and moderate drought can result in increases of carbon-based and nitrogen-based chemical defences, whereas long and severe drought events can result in decreases in plant secondary defence compounds. We predict that different herbivore feeding guilds will show different but predictable responses to drought events, with most feeding guilds being negatively affected by water stress, with the exception of wood borers and bark beetles during severe drought and sap-sucking insects and leaf miners during moderate and intermittent drought. Time of feeding and host specificity are important considerations. Some insects, regardless of feeding guild, prefer to feed on younger tissues from leaf flush, whereas others are adapted to feed on senescing tissues of severely stressed trees. We argue that moderate water stress could benefit specialist insect herbivores, while generalists might prefer severe drought conditions. Current evidence suggests that insect outbreaks are shorter and more spatially restricted in tropical than in temperate forests. We suggest that future research on the impact of drought on insect communities should include (i) assessing how drought-induced changes in various plant traits, such as secondary compound concentrations and leaf water potential, affect herbivores; (ii) food web implications for other insects and those that feed on them; and (iii) interactions between the effects on insects of increasing drought and other forms of environmental change including rising temperatures and CO2 levels. There is a need for larger, temperate and tropical forest-scale drought experiments to look at herbivorous insect responses and their role in tree death.

Jugovic J., Kržič A.

We studied the behavior and oviposition preferences in Aporia crataegi. The study was conducted in a network of dry karst meadows with hedgerows consisted mainly of host plants (Crataegus monogyna; Prunus spinosa, Prunus mahaleb, Rosa sp.) between them. We recorded 15 different behaviours that we divided into six categories: (1) behaviours connected to flight (9 different behaviors), resting (2 behaviors); and (3) feeding, (4) courtship, (5) copula and (6) oviposition with one behaviour each. Males proved to spend most of their time on wings patrolling, while females were more sedentary, but still actively flying and searching for nectar sources and oviposition sites. Differences in behaviour between the sexes were less prominent during the morning but increased during the midday and afternoon, as the males became more active but females were resting and feeding more, probably after searching for host plants and egg-laying earlier in the day. Most commonly, C. monogyna was chosen for oviposition by females, but we found a single oviposition site on P. mahaleb as well. Females lay their eggs in clusters of an average size (AVG±SD/SE) of 34.4±12.8/2.05 eggs, and from a single to up to seven oviposition sites were recorded per host plant. Since the number of eggs in each recorded plant with four or more oviposition sites exceeded an upper limit of eggs laid by a single female reported in literature, females either can lay more eggs or more than one female chose the same host plant. Occupied host plants had similar characteristics as the ones occupied with larvae; females preferably choose smaller shrubs, exposed to the sun with a high percentage (>50%) of a leaf litter coverage underneath them.

Wilson R.J., Brooks S.J., Fenberg P.B.

Body size has been shown to decrease with increasing temperature in many species, prompting the suggestion that it is a universal ecological response. However, species with complex life cycles, such as holometabolous insects, may have correspondingly complicated temperature-size responses. Recent research suggests that life history and ecological traits may be important for determining the direction and strength of temperature-size responses. Yet, these factors are rarely included in analyses. Here, we aim to determine whether the size of the bivoltine butterfly, Polyommatus bellargus, and the univoltine butterflies, Plebejus argus and Polyommatus coridon, change in response to temperature and whether these responses differ between the sexes, and for P. bellargus, between generations. Forewing length was measured using digital specimens from the Natural History Museum, London (NHM), from one locality in the UK per species. The data were initially compared to annual and seasonal temperature values, without consideration of life history factors. Sex and generation of the individuals and mean monthly temperatures, which cover the growing period for each species, were then included in analyses. When compared to annual or seasonal temperatures only, size was not related to temperature for P. bellargus and P. argus, but there was a negative relationship between size and temperature for P. coridon. When sex, generation, and monthly temperatures were included, male adult size decreased as temperature increased in the early larval stages, and increased as temperature increased during the late larval stages. Results were similar but less consistent for females, while second generation P. bellargus showed no temperature-size response. In P. coridon, size decreased as temperature increased during the pupal stage. These results highlight the importance of including life history factors, sex, and monthly temperature data when studying temperature-size responses for species with complex life cycles.

Nijhout H.F., Tao D., McKenna K.Z.

AbstractAdult forms emerge from the relative growth of the body and its parts. Each appendage and organ has a unique pattern of growth that influences the size and shape it attains. This produces adult size relationships referred to as static allometries, which have received a great amount of attention in evolutionary and developmental biology. However, many questions remain unanswered, for example: What sorts of developmental processes coordinate growth? And how do these processes change given variation in body size? It has become increasingly clear that nutrition is one of the strongest influences on size relationships. In insects, nutrition acts via insulin/TOR signaling to facilitate inter- and intra-specific variation in body size and appendage size. Yet, the mechanism by which insulin signaling influences the scaling of growth remains unclear. Here we will discuss the potential roles of insulin signaling in wing-body scaling in Lepidoptera. We analyzed the growth of wings in animals reared on different diet qualities that induce a range of body sizes not normally present in our laboratory populations. By growing wings in tissue culture, we survey how perturbation and stimulation of insulin/TOR signaling influences wing growth. To conclude, we will discuss the implications of our findings for the development and evolution of organismal form.

Gülmez Y.

In this study, forewing teratology in 42 species of solitary wasps belonging to the family Sphecidae (Hymenoptera) collected from various provinces of Turkey were investigated for the first time. In total, 20 cases of wing venation anomalies, classified as: a) irregular vein course, b) supernumerary veins, c) defective veins and d) supernumerary cells, were observed in 112 of 1682 specimens. The most encountered wing venation anomalies were: a spur protruding from 1 m-cu to 1st discoidal cell (n = 42, 37.50%), an incomplete 1r-m cross-vein (n = 21, 18.75%), and completely reduced 1r-m cross-vein (n = 10, 8.92%). The anomalies were rather common in the species Podalonia fera (n = 19, 36.53%), P. luffi (n = 11, 33.33%), P. hirsuta (n = 18, 33.33%) and Chalybion walteri (n = 1, 33.33%). In general, anomalies were more frequently observed in male wasps (n = 65, 58.03%). Teratology could be caused by genetic, environmental or pathogenic factors.

Brooks M., Kristensen K., Benthem K.,., Magnusson A., Berg C., Nielsen A., Skaug H., Mächler M., Bolker B.

Tigreros N., Davidowitz G.

Winged insects often spend considerable amounts of energy in flight, searching for food, escaping predators, and dispersing. In females, flight is hypothesized to reduce resources available for egg production, thus leading to a tradeoff between flight and fecundity. Yet, the generality of a flight-fecundity tradeoff in insects may have been overestimated, given that empirical validation of such a tradeoff has largely relied on studies in wing-polymorphic insects. In this review, we evaluate evidence of a flight-fecundity tradeoff in wing-monomorphic insects by conducting a systematic literature search. We compiled information from studies on migratory and non-migratory insects, testing for an association between flight and fecundity and using a number of different methods—phenotypic and genotypic correlations, manipulation of resource availability, and manipulation of either flight or fecundity. Although most studies indicated a negative association between flight and fecundity in wing-monomorphic insects, evidence for a tradeoff between the two traits was less prevalent. In several contexts, there were species that showed none or a positive association between both traits. Importantly, flight and fecundity in wing-monomorphic insects was related in a number of ways: via physiological constraints—resource-based tradeoffs—as well as via biomechanical constraints—when egg loads affected take-off performance—, due to adaptive negative correlations—when switching from flight to egg production if appropriate conditions to reproduce were encountered—and, due to adaptive positive correlations—when optimal flight and high fecundity were favoured for colonizing new habitats.