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Phytophagous insects may be expected to prefer host-plant species on which their larvae perform best, but this has rarely been explored in grass-feeding butterflies. We explored links between oviposition preferences, larval food preferences, and performance (larval survival and development time, pupal mass, and adult longevity) on 18 species of grass in the common evening brown, Melanitis leda L. (Nymphalidae: Melanitini), a tropical butterfly that has been recorded from a large number of species of grass. Melanitis leda oviposited on all of the grass species offered in choice experiments, and larvae were able to develop to the adult stage on almost all of them. Oviposition preferences were for species of plants on which larval survival was higher, but were not correlated with larval development. The mother's choice of host plant appeared to affect performance of the resulting adults as large butterflies had longer life spans. Ovipositing females appeared to adjust clutch size and position of their eggs on a plant depending on plant traits. Larval survival was only marginally correlated with larval growth rate on the different species of plants. Larvae showed host-plant preferences that were not correlated with adult oviposition preferences, larval survival, or larval growth. Overall, while M. leda can utilize a large number of species of grass, it shows marked oviposition preferences. Apparent fine-tuning of clutch size and positioning of eggs on plants with different traits might be another adaptation associated with using a large number of species of plants. We conclude that this grass feeding butterfly selects oviposition sites that maximize the chances of their larvae surviving.

International audience; Communities of herbivorous insects on individual host trees may be driven by processes ranging from ongoing development via recent microevolution to ancient phylogeny, but the relative importance of these processes and whether they operate via trophic interactions or herbivore movement remains unknown. We determined the leaf phenology, trunk diameter, genotype, and neighbourhood of sessile oak trees (Quercus petraea), and sampled their caterpillar communities. We found that leaf development across a time period of days related to free-living caterpillars, which disappeared with leaf age. Tree growth across decades is related to increased parasitism rate and diversity of herbivores. The microevolution of oak trees across millennia is related to the abundance of leaf-mining casebearers, which is higher on more homozygous oaks. However, oak genome size was not important for any guild. In contrast to most previous studies, the phylogenetic distance of oaks from their neighbours measured in millions of years was associated with higher abundances of entire caterpillar guilds. Furthermore, on trees surrounded by only distantly related tree species, parasitism tended to be lower. Lower parasitism, in turn, was associated with higher abundances of codominant caterpillar species. Neighbourhoods and traits of trees were also related to community composition and diversity, but not to the average wingspans or specialization of species, consistent with the assembly of herbivore communities being driven by leaf traits and parasitism pressure on trees rather than by insect movement among trees. However, movement in rarer species may be responsible for concentration effects in more phylogenetically distant neighbourhoods. Overall, we suggest that the assembly of insects on a tree is mostly driven by trophic interactions controlled by a mosaic of processes playing out over very different time scales. Comparisons with the literature further suggest that, for oak trees, the consequences of growing amongst distantly related tree species may depend on factors such as geographic region and tree age.

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.

Information on the mating system of an insect species is necessary to gain insight into sexual selection and population structure. Male territoriality of the common evening brown butterflyMelanitis ledahas been studied in the wild, but other aspects of its mating system remain largely unknown. For a population ofM. ledain South India, we observed male-male and male-female interactions in captivity, measured mating duration and spermatophore mass, and also determined the degree of polyandry in the wild. We found that mating behavior takes place for short periods of time around dawn and dusk. Our observations corroborate that males compete in aerial combats (twirling) and interfere with mating pairs. In the morning, they may use shivering to warm up. Females can twirl with males and refuse mating by pointing their abdomens upwards or by flying away. Males court females by fluttering their wings while perched behind females, and then initiate copulation by curling their abdomens ca. 180 degrees sideways to make genital contact. While in the morning, matings lasted on average one hour and twenty-three minutes and never exceeded three hours, in the evening, matings could be of similar duration, but 42% of butterflies only separated when dawn was approaching. However, such long nocturnal matings did not result in heavier spermatophores. The first spermatophore of a male tended to be larger than subsequent spermatophores. Together with previous studies on this species, our findings suggest that males compete mainly through territorial defense (as reported before), courtship performance, and interference, and to a lesser extent by providing spermatophores, while females exert some control over the mating system by the timing of their receptivity and mate choice.

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.

Reproductive data of individual insects are extremely hard to collect under natural conditions, thus the study of research questions related to oviposition has not advanced. Patterns of oviposition are often inferred only indirectly, through monitoring of host infestation, whereas the influence of age structure and several other factors on oviposition remains unknown. Using a new approach, in this article, we live-trapped wild Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) females on the Greek island of Chios during two field seasons. For their remaining lifetime, these females were placed individually in small cages and their daily oviposition was monitored. Reproduction rates between cohorts from different collection dates were then compared. The results showed that in the different captive cohorts the average remaining lifetime and reproduction were highly variable within and between seasons. Multivariate regression analysis showed that the month of capture had a significant effect on captive life span, average daily reproduction, and patterns of egg laying. The effect of year was significant on reproduction, but not on captive life span. These differences between sampling periods probably reflect differences in the availability of hosts and other factors that vary during the season and affect age structure and reproduction. Using a non-parametric generalized additive model, we found a statistically significant correlation between the captive life span and the average daily reproduction. These findings and the experimental approach have several important implications.

Although the general concept of capital vs. income breeding has become widely used in insect ecology, finding easy-to-measure indices for quantifying the role of larval- vs. adult-derived nutrients in egg production has remained a challenge. When searching for possible candidates for this task, we evaluated the applicability of three morphometric ratios to be measured on freshly eclosed adults: (1) relative size of female abdomen, (2) sexual size dimorphism, and (3) proportion of volume of mature eggs relative to total volume of female abdomen. We report the values of these indices in five species of geometrid moths [Hypomecis punctinalis Scopoli, Ematurga atomaria L., Selenia tetralunaria Hufnagel, Semiothisa clathrata L., and Epirrhoe alternata Muller (all Lepidoptera: Geometridae)] and compare them to the degrees of income breeding measured directly by oviposition experiments. As a comparison, we also recorded the ovigeny index and the effect of income on lifespan. All morphometric indices varied considerably between the species studied, and, as predicted, the values of all three proposed indices were higher in the more capital-breeding species. The only exception to this pattern was a low proportion of mature eggs in abdomens in one primarily capital-breeding species, S. tetralunaria. Unlike other capital breeders, this species also proved to be largely synovigenic, indicating that capital breeding and pro-ovigeny are not strictly linked. The reproductive traits measured concord with ecological niches occupied by the species studied: the oligophagous meadow dwellers were largely income breeding and synovigenic, whereas the polyphagous forest dwellers were capital breeders. The high and predictable among-species variation in egg-production strategies suggests that geometrid moths form a promising target group for comparative studies on respective traits. Simple anatomical indices, in turn, appear to be applicable as easy-to-record proxies of egg production strategies.

In polygynous insect species, male reproductive success is directly related to lifetime mating success. However, the costs for males of sexual activities such as courting, signaling, and mating are largely unknown. We studied the cost of sexual activities in male Mediterranean fruit flies, Ceratitis capitata (Tephritidae), a polygynous lekking species, by keeping cohorts of individual male flies under relaxed crowding conditions in the laboratory. We used 5 cohorts among which individuals differed in their opportunities to interact with con-specifics and recorded life span, and in one treatment, mating rate. We found that males kept singly lived more than twice as long as males that interacted intensively with mature virgin females, while male–male interactions caused a smaller reduction in longevity. Because longevity of males that could court but not mate was not significantly different from those that could court and mate, we conclude that courting (not mating) was responsible for the observed longevity reduction. Moreover, we detected high variability in male mating success, when 5 virgin females were offered daily. In contrast to the cohort level, individual males that mated at a high rate lived relatively long, thus indicating heterogeneity in quality or sexual strategy among males.

The term 'puddling' includes feeding on (dried) mud and various excrements and secretions of vertebrates, and carrion. It is thought to be a form of supplementary feeding, not targeted at obtaining energy. Although the natural history of the puddling phenomenon in herbivorous arthropods becomes better known, it is still largely unclear how puddling (in particular for sodium) affects fitness despite the growing knowledge of insect physiology at the cellular level. If we follow the definition used for puddling in Lepidoptera, representatives of a wide range of herbivorous and detrivorous terrestrial arthropods (Lepidoptera, Orthoptera, Blattodea, Hymenoptera, Hemiptera, Diptera, and Diplopoda) have been observed to puddle. It appears that those species with diets low in sodium (e.g., folivorous larvae) puddle for sodium whereas those with diets low in nitrogen (e.g., detritivores) puddle for nitrogen. Sex differentials in puddling behavior can usually be explained by transfers of nutrients from males to females during mating. Puddling is rare or absent in immature stages and there is some evidence that nutrients from puddles increase female reproductive success. Strong evidence for the widely cited hypothesis that sodium from puddles is used to enhance neuromuscular activity is still lacking. High mobility and long life spans could be associated with puddling behavior, whereas insects that are concealed or well defended are less likely to puddle (e.g., beetles). The role that risks of pathogen and parasite infection as well as predation at puddling substrates may play in the evolution of puddling remains virtually unexplored.

Fruit-feeding butterflies can experience a more nutrient rich adult diet than nectar-feeding species, and can be expected to use these nutrients for egg production. Here we compare life span, and reproduction parameters of wild-caught females of large and long-lived species on either a sucrose or a mashed banana diet. With small sample sizes per species, but rich longitudinal data for each individual, we examined the longitudinal reproduction pattern, egg size and hatchability of these butterflies in captivity. Diet significantly affected mortality in captivity in a time-dependent manner. On average, we found that butterflies fed mashed banana laid 1.855 times more eggs than those fed sugar. They laid significantly more eggs when they laid and conserved egg size with age while butterflies fed sucrose showed significantly declining egg sizes. Egg hatchability was not significantly affected by diet. Long pre-oviposition periods, significantly smaller first eggs, and absence of age at capture effects on intensity of reproduction indicate low reproduction rates in the field that are due to low food availability. With our small sample sizes, we did not detect significant differences between the species in their response to the diet treatments.

Fruit-feeding butterflies are among the longest lived Lepidoptera. While the use of pollen-derived amino acids by Heliconius butterflies has been interpreted as important for the evolution of extended lifespans, very little is known about the life-history consequences of frugivory. This issue is addressed by investigating effects of four adult diets (sugar, sugar with amino acids, banana, and moistened banana) on lifespan and reproduction in the fruit-feeding butterfly Charaxes fulvescens Aurivillius (Lepidoptera: Nymphalidae). Female butterflies were collected from Kibale National Park, Uganda, and kept individually in cages near their natural habitat and data were collected on lifespan, oviposition, and hatching of eggs. Lifespan in captivity was longer for the sugar and the amino acid cohort, than for the banana cohorts. The longitudinal pattern of oviposition was erratic, with many days without oviposition and few periods with high numbers of eggs laid. Butterflies typically did not lay eggs during their 1st week in captivity and the length of the period between capture and first reproduction was significantly shorter for butterflies fed moistened banana. The length of the reproduction period (first reproduction–last reproduction in captivity) and the reproduction rate (total number of eggs/length of the reproduction period) did not differ significantly between the diet treatments. Those fed with amino acid and moistened banana had significantly higher egg hatchability than those fed with sugar and banana. We found no evidence for a lifespan cost of reproduction. Our results show that (1) female C. fulvescens can use amino acids in their diet for laying fertile eggs, (2) more wing-wear does correlate with lower survival in captivity (indicating aging in the wild), but not with intensity of reproduction (providing no evidence for reproductive aging), and (3) fruit-feeding butterflies may be dietary restricted in the field.

Crop-raiding is a significant problem in small-scale farming, both for the people who depend on their crops and the success of conservation projects. Here, we present the results of a survey on subsistence agriculture, describing crop damage and methods to prevent them, in three communities (35 households) at the northern periphery of the Dja Faunal Reserve, in Cameroon. A total of 96.7% of fields experienced crop damage, 13 species were responsible for this damage, and small mammals, such as cane rat, were the most severe (73% fields affected). None of the methods to prevent damage to crops was negatively correlated with damage. Cumulative damage was negatively correlated with the distance from the forest only on the peanut fields. Distance of a field to the forest was negatively correlated with crop-raiding by only one of the 13 species: the agile mangabeys. Species that were the subject of conservation efforts were responsible for a small proportion of the damage.

International audience; Predation can be one of the key factors that determine abundance in insect herbivore communities, and drive evolution of body size, and anti-predator traits, including crypsis. Population dynamics and selection pressures will depend on the identity of dominant predators in the system, and these may vary substantially among habitats. Arthropods emerge as chief predators on caterpillars in the understorey of non-montane tropical forest, whereas birds dominate elsewhere. In a tropical forest in Uganda, Africa, we evaluated marks on dummy caterpillars that differed in size, material (clay vs. dough), colourant, and plant species on which dummy caterpillars were exposed. We included live caterpillars to estimate the extent to which studies using artificial caterpillars reflect actual levels of predation. Ants and wasps were the most important damagers of dummy caterpillars, whereas bug and beetle damage was very rare, and no bird or small mammal damage was observed. Daily attack rates did not differ significantly from apparent mortality of live caterpillars (daily mortality = 12.1%), but dummy caterpillars made from dough were attacked more frequently (daily attack rate = 18.4%) than those from clay (daily attack rate = 6.9%). Caterpillars of different colour and size, and caterpillars exposed on different plant species had the same chances to be predated. This is in contrast to results from temperate area studies where birds dominate and are not affected by dummy caterpillar material, but prefer larger caterpillars. Our results are consistent with dominant predators on tropical forest caterpillars being invertebrates that are more chemically than visually oriented, so that: (1) material used for dummy caterpillars is important, (2) background matching is relatively unimportant, and (3) being large may have less of a cost. These patterns in predation might facilitate polyphagy and evolution of large body size in tropical Lepidoptera