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Recent advances in molecular systematics have led to an emerging understanding of the phylogenetic history of the family Geometridae. These studies have basically confirmed the traditional subdivision of the subfamily Larentiinae into tribes but unsolved problems remain. Here we test the monophyly of the tribe Perizomini, and evaluate the division of this tribe into genera using Bayesian and maximum likelihood analyses of one mitochondrial and eight nuclear gene fragments. We show that the Eurasian members of Perizoma Hübner, 1825, Mesotype Hübner, 1825 and Gagitodes Warren, 1893 together form a monophyetic tribe Perizomini. However, Martania Mironov, 2000 is not closely related to these genera, but is considered to belong to Melanthiini according to the results of the phylogenetic analyses. Morphological evidence supporting this rearrangement is discussed. The Nearctic Larentia basaliata Walker, 1862 was shown to belong in the genus Martania as M. basaliata (Walker, 1862) comb. nov. and being specifically distinct from the morphologically similar Palaearctic M. taeniata. Three other studied ‘Perizoma’ species from the New World were similarly placed far from Perizomini in the phylogenetic tree, and were not related to each other. We conclude that both the tribe Perizomini and the genus Perizoma are polyphyletic which indicates that the group needs a global revision. It remains an open question whether Perizomini have a worldwide distribution as previously assumed, or is this tribe confined to the Palaearctic region.

Nola estonica Õunap sp. nov. (Lepidoptera, Nolidae, Nolinae) is described based on type material from Estonia. The lectotype is designated for Glaphyra atomosa Bremer, 1861, which is reinstated from a subspecies of Nola aerugula (Hübner, [1793]) to a full species: Nola atomosa (Bremer, 1861) stat. rev. The status of these three taxa as separate species is supported by the results of phylogenetic analysis of DNA barcodes, as well as external and genital morphology of adult specimens. Two new synonyms are established as follows: Nola atomosa (Bremer, 1861) = Nola candidalis Staudinger, 1892 syn. nov. and Nola shin Inoue, 1982 syn. nov. N. estonica occurs sympatrically with N. aerugula in Estonia, and with N. atomosa in South Korea and easternmost Russia. While the available data suggest a disjunct distribution of N. estonica (eastern Europe and the temperate Far East), it appears highly possible that the species has a wide transpalaearctic distribution.

Ecological and life-history data on the Northern European macromoth (Lepidoptera: Macroheterocera) fauna is widely available and ideal for use in answering phylogeny-based research questions: for example, in comparative biology. However, phylogenetic information for such studies lags behind. Here, as a synthesis of all currently available phylogenetic information on the group, we produce a supertree of 114 Northern European macromoth genera (in four superfamilies, with Geometroidea considered separately), providing the most complete phylogenetic picture of this fauna available to date. In doing so, we assess those parts of the phylogeny that are well resolved and those that are uncertain. Furthermore, we identify those genera for which phylogenetic information is currently too poor to include in such a supertree, or entirely absent, as targets for future work. As an aid to studies involving these genera, we provide information on their likely positions within the macromoth tree. With phylogenies playing an ever more important role in the field, this supertree should be useful in informing future ecological and evolutionary studies.

If the evolutionary determinants of longevity were mainly extrinsic, related species from different habitats should systematically differ in individual lifespans. Comparative studies of insects can significantly contribute to understanding the evolution of lifespan, as the trait can feasibly be measured in a high number of species. We recorded adult longevities for 110 species of geometrid moths from a tropical community. Comparative analyses based on an original phylogenetic reconstruction were applied to reveal the correlates of species-specific values of lifespan. Larger moth species were found to live longer, and females tended to have shorter lifespans than males. Average adult lifespans in tropical geometrids, and the relationships of lifespan with other variables, were found to be highly similar to those reported for their temperate region relatives. The among-region similarity leads to the conclusion of the dominance of intrinsic (physiological) determinants of longevity over the extrinsic (ecological) ones: the contrasting environments of tropical and temperate forests have not produced detectable differences in moth longevities.

1. Comparative studies on insect life histories are facilitated by the increasing availability of reliable phylogenies but are hampered by the scarcity of comparable data. Fortunately, morphological proxies of some life‐history traits can be measured on preserved specimens. 2. This study compared values of size‐related life‐history traits among a tropical (Ugandan) and a temperate (Estonian) assemblage of geometrid moths. 3. A comparative analysis based on an originally derived phylogeny revealed that tropical moths were, on average, larger than temperate ones. Tropical moths also had somewhat lower relative abdomen masses than temperate ones. This indicates that the tropical rather than the temperate moths tend to use an income (rather than capital) breeding strategy. Nevertheless, no difference was found in a related index of pro‐ovigeny. When body size was accounted for, tropical moths were found to lay smaller eggs than temperate ones. 4. The differences between the two compared areas are consistent with selection on higher mobility of the moths imposed by the more diverse tropical vegetation. Relatively larger eggs of temperate moths may constitute an adaptation to overcome the presumably stronger quantitative defences of their host plants. 5. Overall, however, we conclude that the differences in ecologically relevant size‐related traits are relatively low among moth assemblages of a tropical and a temperate forest region, indicating that these environments may not impose radically different selective pressures on insect life histories.

Seasonal polyphenism constitutes a specific type of phenotypic plasticity in which short‐lived organisms produce different phenotypes in different times of the year. Seasonal generations of such species frequently differ in their overall lifespan and in the values of traits closely related to fitness. Seasonal polyphenisms provide thus excellent, albeit underused model systems for studying trade‐offs between life‐history traits. Here, we compare immunological parameters between the two generations of the European map butterfly (Araschnia levana), a well‐known example of a seasonally polyphenic species. To reveal possible costs of immune defence, we also examine the concurrent differences in several life‐history traits. Both in laboratory experiments and in the field, last instar larvae heading towards the diapause (overwintering) had higher levels of both phenoloxidase (PO) activity and lytic activity than directly developing individuals. These results suggest that individuals from the diapausing generation with much longer juvenile (pupal) period invest more in their immune system than those from the short‐living directly developing generation. The revealed negative correlation between pupal mass and PO activity may be one of the reasons why, in this species, the diapausing generation has a smaller body size than the directly developing generation. Immunological parameters may thus well mediate trade‐offs between body size‐related traits.

Conspecific females and males often follow different development trajectories which leads to sex differences in age at maturity (sexual bimaturism, SBM). Whether SBM is typically selected for per se (direct selection hypothesis) or merely represents a side-effect of other sex-related adaptations (indirect selection hypothesis) is, however, still an open question. Substantial interspecific variation in the direction and degree of SBM, both in invertebrates and vertebrates, calls for multi-species studies to understand the relative importance of its evolutionary drivers. Here we use two complementary approaches to evaluate the evolutionary basis of SBM in insects. For this purpose, we assembled an extensive literature-derived data set of sex-specific development times and body sizes for a taxonomically and ecologically wide range of species. We use these data in a meta-analytic framework to evaluate support for the direct and indirect selection hypotheses. Our results confirm that protandry - males emerging as adults before females - is the prevailing form of SBM in insects. Nevertheless, protandry is not as ubiquitous as often presumed: females emerged before males (= protogyny) in about 36% of the 192 species for which we had data. Moreover, in a considerable proportion of species, the sex difference in the timing of adult emergence was negligible. In search for the evolutionary basis of SBM, we found stronger support for the hypothesis that explains SBM by indirect selection. First, across species, the direction and degree of SBM appeared to be positively associated with the direction and degree of sexual size dimorphism (SSD). This is consistent with the view that SBM is a correlative by-product of evolution towards sexually dimorphic body sizes. Second, within protandrous species, the degree of protandry typically increased with plastic increase in development time, with females prolonging their development more than males in unfavourable conditions. This pattern is in conflict with the direct selection hypothesis, which predicts the degree of protandry to be insensitive to the quality of the juvenile environment. These converging lines of evidence support the idea that, in insects, SBM is generally a by-product of SSD rather than a result of selection on the two sexes to mature at different times. It appears plausible that selective pressures on maturation time per se generally cannot compete with viability- and fecundity-mediated selection on insect body sizes. Nevertheless, exceptions certainly exist: there are undeniable cases of SBM where this trait has evolved in response to direct selection. In such cases, either the advantage of sex difference in maturation time must have been particularly large, or fitness effects of body size have been unusually weak.

International audience; Evading predators is a fundamental aspect of the ecology and evolution of all prey animals. In studying the influence of prey traits on predation risk, previous researchers have shown that crypsis reduces attack rates on resting prey, predation risk increases with increased prey activity, and rapid locomotion reduces attack rates and increases chances of surviving predator attacks. However, evidence for these conclusions is nearly always based on observations of selected species under artificial conditions. In nature, it remains unclear how defensive traits such as crypsis, activity levels, and speed influence realized predation risk across species in a community. Whereas direct observations of predator-prey interactions in nature are rare, insight can be gained by quantifying bodily damage caused by failed predator attacks. 2). We quantified how butterfly species traits affect predation risk in nature by determining how defensive traits correlate with wing damage caused by failed predation attempts, thereby providing the first robust multi-species comparative analysis of predator-induced bodily damage in wild animals. 3). For 34 species of fruit-feeding butterflies in an African forest, we recorded wing damage and quantified crypsis, activity levels, and flight speed. We then tested for correlations between damage parameters and species traits using comparative methods that account for measurement error. 4). We detected considerable differences in the extent, location, and symmetry of wing surface loss among species, with smaller differences between sexes. We found that males (but not females) of species that flew faster had substantially less wing surface loss. However, we found no correlation between cryptic colouration and symmetrical wing surface loss across species. In species in which males appeared to be more active than females, males had a lower proportion of symmetrical wing surface loss than females. 5). Our results provide evidence that activity greatly influences the probability of attacks and that flying rapidly is effective for escaping pursuing predators in the wild, but we did not find evidence that cryptic species are less likely to be attacked while at rest.

1. Juvenile growth trajectories evolve via the interplay of selective pressures on age and size at maturity, and developmental constraints. In insects, the moulting cycle is a major constraint on larval growth trajectories. 2. Surface area to volume ratio of a larva decreases during growth, so renewal of certain surfaces by moulting is likely needed for the maintenance of physiological efficiency. A null hypothesis of isometry, implied by Dyar’s Rule, would mean that the relative measures of growth remain constant across moults and instars. 3. We studied ontogenetic changes and allometry in instar‐specific characteristics of larval growth in 30 lepidopteran species in a phylogenetic comparative framework. 4. Relative instar‐specific mass increments (RMI) typically, but not invariably, decreased across instars. Ontogenetic change in RMIs varied among families with little within‐family variation. End‐of‐instar growth deceleration (GD) became stronger with increasing body size across instars. Across‐instar change in GD was conserved across taxa. Ontogenetic allometry was generally non‐isometric in both RMI and GD. 5. Results indicate that detailed studies on multiple species are needed for generalizations concerning growth trajectory evolution. Developmental and physiological mechanisms affecting growth trajectory evolution show different degrees of evolutionary conservatism, which must be incorporated into models of age and size at maturation.

Research on evolutionary forces determining optimal body sizes has primarily relied on experimental evaluation of respective selective pressures. Accounting for among-species variation through application of phylogenetic comparative methods is a complementary although little used approach. It enables the direct association of body size values with particular environments. Using phylogenetically explicit comparative analyses, we show that small body size is associated with diurnal (rather than nocturnal) activity of adults among temperate species of the moth family Geometridae. The association of an exclusively adult trait with species-specific body size suggests that optimal body sizes are at least partly determined by the costs being a large adult, as opposed to the more frequently considered costs of attaining large size. It appears likely that size-selective predation by insectivorous birds is the primary factor responsible for selection against large body size in day-flying moths.

Understanding how and why some groups have become more species-rich than others, and how past biogeography may have shaped their current distribution, are questions that evolutionary biologists have long attempted to answer. We investigated diversification patterns and historical biogeography of a hyperdiverse lineage of Lepidoptera, the geometrid moths, by studying its most species-rich tribe Boarmiini, which comprises ca. 200 genera and ca. known 3000 species. We inferred the evolutionary relationships of Boarmiini based on a dataset of 346 taxa, with up to eight genetic markers under a maximum likelihood approach. The monophyly of Boarmiiniis strongly supported. However, the phylogenetic position of many taxa does not agree with current taxonomy, although the monophyly of most major genera within the tribe is supported after minor adjustments. Three genera are synonymized, one new combination is proposed, and four species are placed in incertae sedis within Boarmiini. Our results support the idea of a rapid initial diversification of Boarmiini, which also implies that no major taxonomic subdivisions of the group can currently be proposed. A time-calibrated tree and biogeographical analyses suggest that boarmiines appeared in Laurasia ca. 52 Mya, followed by dispersal events throughout the Australasian, African and Neotropical regions. Most of the transcontinental dispersal events occurred in the Eocene, a period of intense geological activity and rapid climate change. Diversification analyses showed a relatively constant diversification rate for all Boarmiini, except in one clade containing the species-rich genus Cleora. The present work represents a substantial contribution towards understanding the evolutionary origin of Boarmiini moths. Our results, inevitably biased by taxon sampling, highlight the difficulties with working on species-rich groups that have not received much attention outside of Europe. Specifically, poor knowledge of the natural history of geometrids (particularly in tropical clades) limits our ability to identify key innovations underlying the diversification of boarmiines.

Latitudinal and elevational trends in body size are found in numerous animal taxa, with various adaptive explanations proposed. It is however debatable whether geographic trends in adult body size are accompanied by corresponding differences in juvenile growth rate (= mass gain per unit time). Respective studies have been complicated by conceptual and methodological problems related to defining and measuring this variable, particularly in organisms with discontinuous growth like arthropods. Using an original method for estimating differential (instantaneous) juvenile growth rates, we compared geographically distant European populations of six insect species in a common garden experiment. We found no among population differences in differential growth rate in any of the species. This result is in concert with concurrent increase in both adult size and developmental time towards the south. While opposite examples exist, we interpret our results as challenging the view that growth rate is a trait that readily responds to environmentally based selective pressures. Our results thus advocate the more classical view of growth rate maximisation within its physiological limits. We discuss the advantages of using differential (rather than integral) measures of growth rate in evolutionary ecological studies and evaluate the reasons for the detected latitudinal trends in life history traits.

Specificity is one of the fundamental concepts in ecology. Host specificity of phytophagous insects has been of particular interest because of its crucial role in diversification and life-history evolution. However, the majority of tropical insects remain insufficiently explored with respect to their host-plant relations. A lack of respective data is also hindering the debate over whether higher levels of host-plant specificity prevail in tropical insects compared to temperate ones. We investigated host-plant specificity of forest geometrid moths (Lepidoptera: Geometridae) in equatorial Africa using host-plant acceptability trials with neonate larvae, with the addition of field observations. We compare our experimental data to the (well-known) host-specificity patterns of closely related temperate (hemiboreal) species. Similarly to the temperate region, there were broadly polyphagous tropical species in several clades of Geometridae utilizing hosts belonging to different plant families. Phylogenetic comparative analysis returned no significant differences in host specificity between the two regions. Our study contributes to the evidence that host-plant specificity of herbivores is not necessarily substantially higher in tropical than temperate regions.

Red Lists are very valuable tools in nature conservation at global, continental and (sub-) national scales. In an attempt to prioritise conservation actions for European butterflies, we compiled a database with species lists and Red Lists of all European countries, including the Macaronesian archipelagos (Azores, Madeira and Canary Islands). In total, we compiled national species lists for 42 countries and national Red Lists for 34 of these. The most species-rich countries in Europe are Italy, Russia and France with more than 250 species each. Endemic species are mainly found on the Macaronesian archipelagos and on the Mediterranean islands. By attributing numerical values proportionate to the threat statuses in the different national Red List categories, we calculated a mean Red List value for every country (cRLV) and a weighted Red List value for every species (wsRLV) using the square root of the country’s area as a weighting factor. Countries with the highest cRLV were industrialised (NW) European countries such as the Netherlands, Belgium, the Czech Republic and Denmark, whereas large Mediterranean countries such as Spain and Italy had the lowest cRLV. Species for which a Red List assessment was available in at least two European countries and with a relatively high wsRLV (≥ 50) are Colias myrmidone, Pseudochazara orestes, Tomares nogelii, Colias chrysotheme and Coenonympha oedippus. We compared these wsRLVs with the species statuses on the European Red List to identify possible mismatches. We discuss how this complementary method can help to prioritise butterfly conservation on the continental and/or the (sub-)national scale.

Sex-specific mechanisms of the determination of insect body sizes are insufficiently understood. Here we use the common heath moth, Ematurga atomaria (Lepidoptera: Geometridae) to examine how larval growth trajectories differ between males and females. We monitored the development of 1379 larvae in controlled laboratory conditions. Sexually dimorphic development times during the first four instars were associated with sexual size dimorphism (SSD) in the beginning of the fifth (last) instar, when females were on average 15% heavier than males. Similarly, the duration of the last instar was about 13% longer in females. Further, we specifically focussed on the estimates of differential (instantaneous) growth rates of the larvae based on 24h mass increments of the 2nd, 3rd, 4th and 5th day in the beginning of the last instar. We calculated 'allometric' differential growth rates as the per-day increase in cube-root-transformed mass of the larvae. We found that allometric growth rates were slightly but significantly larger in females than in males. As this measure of growth rate (in contrast to the relative growth rate, based on the ratio of masses recorded at consecutive measurements) did not depend on body size, it allows an unambiguous separation of the effects of sex and size. We conclude that in accordance with an emerging general pattern, larger female body size in E. atomaria is achieved primarily by means of a longer growth period. Furthermore, our study shows that the differential growth rate can also be sexually dimorphic and contribute to SSD. This contribution, however, is lower than that of the development time by an order of magnitude. In addition to development periods and growth rates, other parameters of the non-linear growth curves of insect larvae also need to be considered in the context of SSD determination. In particular, weight loss prior to pupation was shown to be considerably larger in females than in males.

In litter-bearing mammals, the environment and social interactions during early life often have a substantial effect on future behaviour of the animal. Most information though derives from lab rodents, pets or farm animals while comparable data are scarce for non-domesticated species, and endangered carnivores in particular. In this study, we focused on social behaviour of juvenile European mink, with the practical aim to provide information for enhancing the ex-situ breeding programme of this critically endangered species. As the first step, we compiled a detailed ethogram of social behaviour observed among the European mink cubs. For the 13 captive born litters available, we then systematically recorded the relative duration of different types of behaviour during a two months period. The behaviour of the captive cubs was found to be diverse, containing all elements characteristic of congeneric mustelids, with no indication of litters deviating from the typical pattern. In all broods, a considerable and approximately equal share of time was allocated to social play, a suggested indicator of positive welfare. Aggressive behaviour of the mother towards her offspring was minimal when the cubs were young and, increased only with the litter dispersal period approaching. Bites between the cubs during play fighting did not increase with the age of the juveniles. We found no evidence that captive environment adversely affects the behaviour of the juveniles during the first months of their life.

Predictive classifications of life histories are essential for evolutionary ecology. While attempts to apply a single approach to all organisms may be overambitious, recent advances suggest that more narrow ordination schemes can be useful. However, these schemes mostly lack easily observable proxies of the position of a species on respective axes. It has been proposed that, in insects, the degree of capital (vs. income) breeding, reflecting the importance of adult feeding for reproduction, correlates with various ecological traits at the level of among-species comparison. We sought to prove these ideas via rigorous phylogenetic comparative analyses. We used experimentally derived life-history data for 57 species of European Geometridae (Lepidoptera), and an original phylogenetic reconstruction. The degree of capital breeding was estimated based on morphological proxies, including relative abdomen size of females. Applying Brownian-motion-based comparative analyses (with an original update to include error estimates), we demonstrated the associations between the degree of capital breeding and larval diet breadth, sexual size dimorphism, and reproductive season. Ornstein-Uhlenbeck model based phylogenetic analysis suggested a causal relationship between the degree of capital breeding and diet breadth. Our study indicates that the gradation from capital to income breeding is an informative axis to ordinate life-history strategies in flying insects which are affected by the fecundity vs. mobility trade off, with the availability of easy to record proxies contributing to its predictive power in practical contexts.

Understanding ecological requirements of endangered species is a primary precondition of successful conservation practice. Regrettably, we know surprisingly little about the life history of numerous threatened insects, and about their use of larval host plants in particular. The brown butterflies (Nymphalidae: Satyrinae) have traditionally been considered polyphagous on grasses and indiscriminatory in their oviposition behavior. However, detailed studies on several species have revealed local specialization in host plant use as well as the decisive role of microlimatic conditions as determinants of habitat quality. The present study addresses host plant relationships in the endangered brown butterfly Coenonympha hero (L.) at the northern limit of its European distribution. We combine laboratory-based host preference and performance tests with an analysis of microhabitat use by adult butterflies in the field. Both lines of evidence suggest that C. hero is polyphagous enough not to be associated with one particular host species. Oviposition choices of C. hero are not driven by host plant species but rather by structural characteristics of the substrate. The preferred rigid needle-like structures may serve as cues of ‘transparent’ vegetation which allows the larvae to benefit from sunlight reaching the lower strata of the tuft. Our results suggest that conservation efforts should prioritize microclimatic parameters, rather than the presence of any particular host plant species, as decisive determinants of habitat quality in C. hero.

The conservation of forest biodiversity is increasingly relying on forest landscapes managed for timber production. A precondition for successful biodiversity conservation in intensively managed landscapes is a good understanding of habitat- and landscape-level drivers of species diversity. In this study, we investigated the effects of habitat characteristics and landscape context on the species richness and composition of butterflies in temperate forest landscapes routinely managed by clear-cutting. Our focus was on forest-dependent species. Even though about a quarter of the entire butterfly fauna in Europe are associated with forest habitats, the drivers of their diversity are poorly known. We used data from an unprecedentedly extensive butterfly survey, conducted in more than 400 sites distributed across all major forest types in Estonia (Northern Europe). Our data indicate that, generally, forests harvested for timber production remain suitable as habitats for forest butterflies: across the study sites, we recorded almost the full complement of their total regional species richness. By far the most influential driver of local butterfly species richness in such forests appears to be the proportion of forest cover in the surrounding landscape. The species richness of forest butterflies starts to show signs of decline at remarkably high levels of forest cover in the landscape. Surprisingly, landscape-scale forest heterogeneity around study sites had no discernible effect on local species richness, the pattern plausibly resulting from low mobility of forest butterflies. The most important habitat-scale predictor of butterfly species richness was soil moisture, with butterfly communities being most species-rich in forests on soils of intermediate moisture. Different forest types contribute to the regional species pool of forest butterflies in a complementary manner. No single forest type alone provides habitat for the entire species pool: peaks of abundance of different species are distributed across multiple forest types. Accordingly, a substantial part of the variation in species assemblages could be attributed to characteristic soil conditions (moisture and pH) of different forest types. Our findings imply that both the extent and heterogeneity of forest landscapes are important for maintaining the diversity of forest butterflies at the landscape scale.

The idea that the fitness value of body coloration may be affected by biochemically mediated trade-offs has received much research attention. For example, melanization is believed to interact with other fitness-related traits via competition for substrates, costs associated with the synthesis of melanin or pleiotropic effects of the involved genes. However, genetic correlations between coloration and fitness-related traits remain poorly understood. Here, we present a quantitative-genetic study of a coloration trait correlated to melanin-based cuticular darkness ('darkness', hereafter) in a geometrid moth, Ematurga atomaria. This species has considerable variation in larval appearance. We focus on correlations between larval darkness and fitness-related growth performance traits. Both a half-sib analysis and an 'animal model' approach revealed moderately high heritabilities of larval darkness and indices of growth performance. Heritability estimates of darkness derived from the animal model were, however, considerably higher than those based on the half-sib model suggesting that the determination of coloration includes genetic interactions and epigenetic effects. Importantly, on the host plant with the largest sample size, we found no evidence for either genetic or environmental correlations between darkness and growth parameters. On an alternative host plant, there was some indication of positive genetic and negative environmental correlation between these traits. This shows that respective relationships are environment-specific. Nevertheless, the overall pattern of weak and inconsistent correlations between larval coloration and growth parameters does not support universal trade-offs between these traits and suggests that physiological costs of producing colour patterns do not necessarily interfere with adaptive evolution of coloration.

Diet breadth and the degree of capital breeding have been established as major determinants of species-specific ecology of herbivorous insects. Both of these variables are related to resource foraging and therefore can be expected to have effects on sensory capacity. However, such effects have remained poorly studied, let alone in phylogenetically explicit multi-species comparisons. We contribute to filling this gap in a study of 60 species of geometrid moths (Lepidoptera: Geometridae), using adult head measures (eye size, antennal length and shape, forehead width) as indices of sensory capacity. When controlled for body size, eyes of the more capital breeding species (i.e. those with low contribution of adult feeding to reproduction) were found to be smaller, and female antennae shorter, than in income breeders. Feathery (vs simple filiform) male antennae were more frequently present in the capital breeders and in larger species. Regarding diet breadth, generalist species were found to have relatively wider male foreheads than specialists. The results suggest that (a) breeding strategy rather than diet breadth predicts sensory capacity in geometrids, (b) capital breeding (vs income breeding) is related to low sensory capacity in females, and (c) in contrast, males of the capital breeding species have evolved towards elevated olfactory capacity.

Regionally oligophagous insects are often host plant specialists at smaller geographical scales, so conservation planning should preferably rely on locally derived information. Host use of the endangered butterfly Euphydryas aurinia was investigated close to the northern limit of its European distribution. We experimentally studied host preference of ovipositing females and growth performance of pre-diapause larvae on different hosts, as well as made field observations on host use by surveying larval webs. In the field, Succisa pratensis has remained the only confirmed host of E. aurinia in Estonia. Also, in the laboratory, the females consistently preferred S. pratensis as oviposition substrate. Larval performance was the highest on S. pratensis though the insects were also able to develop on Knautia arvensis. By contrast, species of Plantago, or Valeriana officinalis, were not suitable for larval development. E. aurinia appears thus to be a host specialist in Estonia, even if the regional list includes a higher number of plant species. Our results confirm a pattern repeatedly recorded in Melitaeine butterflies, i.e. geographic differences in host use and local monophagy. As a methodological contribution, we showed that different lab-based methods yield consistent information on host use, though tend to somewhat overestimate the actual host range of the species in the field. Using larval growth rate as an index of host suitability appears problematic for species not time-stressed during their larval development, and survival is a more appropriate parameter to record.

Founding captive populations is often the last chance for saving endangered species from extinction. Ensuring successful reproduction is typically most critical for the maintenance of captive populations, with purposeful selection of individuals for breeding being one of the crucial aspects. Comparable cross-species data on the determinants of reproduction success are most useful for solving problems in captive species programs. In the present study, we provide an overview of a 20-year captive breeding program of the critically endangered European mink. The mating season starts in March, reaching its peak in the middle of April. The average gestation length was 43.8 days (mode 43), the mean litter size being 4.4 (mode 4). Litter size and cub survival were negatively correlated with maternal age but this effect was entirely due to the lower performance of the females over 4 years of age. Female body weight also showed a positive correlation with litter size, with the weight itself having increased by 10% during the 20- year period. We did not find any signs of a cost of reproduction: the number of litters the female had delivered earlier in her life did not have an effect on her litter size in the focal year. Beyond the effect of age and size, individual females did not differ in litter sizes. Consistently, we found the heritability of litter size to be low. We conclude that, when selecting females for breeding, there is little need to consider aspects other than genetic relatedness crucial for avoiding progressive inbreeding.

An evolutionary explanation should consider the balance between environmentally-based selective pressures, and the resistance of the organism's phenotype to adaptive evolution, with the latter being captured by the concept of constraint. The limited attention to non-adaptive explanations in evolutionary ecology is at least partly caused by methodological difficulties with respect to identifying and quantifying constraints. As an example of an experimental approach evaluating a constraint-based explanation, we present a cross-species comparison of the shape of reaction norms for size and age at maturity. Instar- and sex-specific development times and final sizes were recorded for two distantly-related species of insects (Lepidoptera), with larval growth rates being manipulated by means of refined starvation treatments. We found that (1) the ‘classical’ L-shaped reaction norms for final size and development time are characteristic also of individual larval instars; (2) these responses show a high degree of quantitative similarity across the species, different larval instars, and sexes within species; and (3) the similarity among species and sexes is higher for the penultimate than for the final instar. The high degree of similarity suggests that some physiological mechanisms determining such reaction norms are evolutionarily conservative. An alternative explanation (i.e. quantitative similarity of ecologically based selective pressures) appears less likely. The results of a previous study on a third lepidopteran species not only support our general conclusions, but also provide a clear case of adaptive evolution in some aspects of such reaction norms. The present study shows one way how the data required to measure evolutionary conservatism in reaction norms for body size can be obtained empirically. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 296–307.