Freerk Molleman | Indian Institute of Science Education and Research Mohali (original) (raw)

Papers by Freerk Molleman

Ecology and evolution, 2016

Sexual traits are often the most divergent characters among closely related species, suggesting a... more Sexual traits are often the most divergent characters among closely related species, suggesting an important role of sexual traits in speciation. However, to prove this, we need to show that sexual trait differences accumulate before or during the speciation process, rather than being a consequence of it. Here, we contrast patterns of divergence among putative male sex pheromone (pMSP) composition and the genetic structure inferred from variation in the mitochondrial cytochrome oxidase 1 and nuclear CAD loci in the African butterfly Bicyclus anynana (Butler, 1879) to determine whether the evolution of "pheromonal dialects" occurs before or after the differentiation process. We observed differences in abundance of some shared pMSP components as well as differences in the composition of the pMSP among B. anynana populations. In addition, B. anynana individuals from Kenya displayed differences in the pMSP composition within a single population that appeared not associated wit...

Journal of evolutionary biology, Jan 18, 2016

Both physiologically and ecologically based explanations have been proposed to account for among-... more Both physiologically and ecologically based explanations have been proposed to account for among-species differences in lifespan but they remain poorly tested. Phylogenetically explicit comparative analyses are still scarce, and those that exist are biased towards homoeothermic vertebrates. Insect studies can significantly contribute as lifespan can feasibly be measured in a high number of species, and the selective forces that have shaped it may differ largely between species and from those acting on larger animals. We recorded adult lifespan in 98 species of geometrid moths. Phylogenetic comparative analyses were applied to study variation in species-specific values of lifespan and to reveal its ecological and life-history correlates. Among-species and between-gender differences in lifespan were found to be notably limited; there was also no evidence of phylogenetic signal in this trait. Larger moth species were found to live longer, with this result supporting a physiological rat...

Journal of Biogeography, 2016

Aim Under spatial isolation on oceanic islands, species tend to show extreme body sizes. From the... more Aim Under spatial isolation on oceanic islands, species tend to show extreme body sizes. From the point of view of many colonizers, individual hosts surrounded by phylogenetically distant neighbours are phylogenetically isolated. This study addresses for the first time how phylogenetic isolation of individual hosts affects body size of colonizers, and whether effects on body size reflect selection among colonizers established on host individuals rather than selection among colonizers dispersing toward trees or phenotypic plasticity of colonizers.

Quantification of chemical defence contributes to the study of animal signals, and to understandi... more Quantification of chemical defence contributes to the study of animal signals, and to understanding trade-offs among defences and life history traits. Some tropical fruit-feeding butterfly species can be expected to have well-developed anti-predator defences because they are long-lived, are host-plant specialists, and/or have contrasting colourations that may be involved in mimicry relationships. Yet, as a group they are often assumed to be palatable, even without supporting data. Palatability is a continuum that embraces within and between prey-species variation, and therefore, both among-and within-species variation must be documented. Palatability of nine species of fruitfeeding butterfly in Uganda was rated using a novel assay. One hundred and twenty-five butterflies were homogenized, their ground tissues suspended in sugar water and these suspensions offered as small droplets to individual ants in Petri dishes. The time ants spent feeding on these droplets was measured. Danaine butterflies were used as unpalatable references, and sugar solution as a palatable reference. Ants tended to eat in significantly shorter bouts from danaines compared to fruitfeeding species, and feeding bouts on pure sugar solution were longest. Within fruit-feeding species, variation in the duration of ants' feeding bouts was very substantial. There was also considerable variation among individual ants, such that large sample sizes would be needed to reliably distinguish palatability of different species of fruit-feeding butterflies. In explorative analyses, at least three fruitfeeding butterfly species that were assumed palatable appeared to be chemically defended. These results suggest that, in contrast to common assumptions, some tropical fruit-feeding butterflies use unpalatability for defence, perhaps contributing to their long life spans in the wild.

Biotropica

In communities of tropical insects, adult abundance tends to fluctuate widely, perhaps in part ow... more In communities of tropical insects, adult abundance tends to fluctuate widely, perhaps in part owing to predator-prey dynamics. Yet, temporal patterns of attack rates in tropical forest habitats have not been studied systematically; the identity of predators of insects in tropical forests is poorly known; and their responses to temporal variation in prey abundance have rarely been explored. We recorded incidence and shape of marks of attacks on dummy caterpillars (proxy of predation rate) in a sub-montane tropical forest in Uganda during a yearlong experiment, and explored correlations with inferred caterpillar abundance. Applying the highest and lowest observed daily attack rates on clay dummies over a realistic duration of the larval stage of butterflies, indicates that the temporal variation in attack rate could cause more than 10-fold temporal variation in caterpillar survival. Inferred predators were almost exclusively invertebrates, and beak marks of birds were very scarce. Attack rates by wasps varied more over time than those of ants. Attack rates on dummies peaked during the two wet seasons, and appeared congruent with inferred peaks in caterpillar density. This suggests (1) a functional response (predators shifting to more abundant resource) or adaptive timed phenology (predators timing activity or breeding to coincide with seasonal peaks in prey abundance) of predators, rather than a numerical response (predator populations increasing following peaks in prey abundance); and (2) that predation would dampen abundance fluctuations of tropical Lepidoptera communities.

Books contain sixty-five full color pages with about 200 butterfly species, images of caterpillar... more Books contain sixty-five full color pages with about 200 butterfly species, images of caterpillars, host-plant information particular to Kibale Forest, and including some information that is new to science.

Aterica galene Kiinu ekihoiholya nikirahuka kukyahukaniza ha bindi ebirukusisana Amauris nororra ... more Aterica galene Kiinu ekihoiholya nikirahuka kukyahukaniza ha bindi ebirukusisana Amauris nororra hamapapa gakyo nkoku gekulingirire, Ebisaija biine eraangi eyerukuzoka neyera hamapapa gabyo agenyuma kandi omubikazi eraangi erukweera eburra mu raangi eyerikwiragura n'eraba muraangi yakyenjukyenju (yellowish). Ebikazi bikooto kukira ebisaija, obwokurorraniza na E. pupae, A. galene ine obukarra bwezabu (gold) obutali butonyezi nkobwa Euphaedra. Ekihoiholya kinu kyalika hamuti ogweetwa Pancovia (Omugangara). female uns female ups Catuna crithea Kinu kihoiholya kitaito, kiharukira hansi muno kiine amapapa agahunzirwe nkekiju kyenyamumKinu kihoiholya kitaito, kiharrukira hansi muno kiine amapapa agomumaiso gahunzirwe nkekiju kyenyamumbubi kandi garaihire. Ekihoiholya kinu nikisakusisana ebihoiholya ebindi nka Euphaedra na Bebearia. Ebyaana byebihoiholya binu nibisisanira kimu ebya Euphaedra kandi byalika hamuti ogweetwa Aningeria (omutooke) hamu nahakahurru akeetwa Sycamona afrikana. Biri mukuterana Euriphene ribensis Ebihoiholya ebikazi ebyekika kinu, biine ebirambirambi byeraangi yakyenjukyenju kutandikira hamapapa gabyo agenyuma kugendera kimu nomugomumaiso. Ebisaija biine eraangii ekwasiire ya blue eyekwangasana kandi biiruka mono. Byalika amahuli gabyo hamuti ogweetwa Bersama. female ups male ups female uns Euriphene saphirina Ebihoiholya Binu ebikazi biine ekirambi haiguru yamapapa gabyo agomumaiso kandi ebisaija biine erangi ekwasire kukira eya E. ribensis. Ekihoiholya kinu tikikira kukanya mukibira.

Magazine article in Estonian about the puddling phenomenon in response to a readers question.

meza seems to be Pardaleodes tibullus torensis -but P. bule is also possible. 26 With thanks to T... more meza seems to be Pardaleodes tibullus torensis -but P. bule is also possible. 26 With thanks to Torben Larsen, Steve Collins, Oskar Brattström, Margaret Nyafwono, Niklas Wahlberg and Erki 27 Õunap.

International Journal of Primatology, 2014

Entomologia Experimentalis et Applicata, 2010

The term 'puddling' includes feeding on (dried) mud and various excrements and secretions of vert... more 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.

Entomologia Experimentalis et Applicata, 2011

Reproductive data of individual insects are extremely hard to collect under natural conditions, t... more 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.

Nitrogenous compounds in the adult diet can play an important role in the nutritional ecology and... more Nitrogenous compounds in the adult diet can play an important role in the nutritional ecology and life history evolution of butterflies. We compared the concentration of δ 15N in fruitfeeding butterflies that feed on faeces and carrion (puddling) versus those that do not feed on these substrates, and used the difference between δ 15 N in bodies versus wings as a measure of the amount of nitrogen derived from animals. Differences between the sexes and between the feeding guilds were small, suggesting that minimal amounts of nitrogen were absorbed from these resources. Males, the sex that does most of the puddling, had higher δ 15 N, but this occurred in both carrion feeders and non carrion feeders. This probably reflects differences in metabolic activity of caterpillars. It appears that caterpillar metabolism and metamorphosis results in significant secondary δ 15 N enrichment and differences among the sexes, and, together with host-plant range and quality, in within species variation in δ 15 N values.

Experimental Gerontology, 2009

This study was concerned with the impact of different levels of artificial impairment (leg amputa... more This study was concerned with the impact of different levels of artificial impairment (leg amputations) on male and female survival and female reproduction in the Mexican fruit fly, Anastrepha ludens. We monitored the demographic responses in a total of 100 flies of each sex that were maintained individually in 4 Â 4 Â 10 cm cages and subject to 1-of-11 different leg amputations (plus intact control) including cohorts in which either one front, one middle or one rear leg was severed (3 cohorts total), in which two legs were severed in different front-middle-rear combinations (6 cohorts total), or in which the two middle and one additional leg were severed (2 cohorts total). The two main findings were that: (i) although the effects on mortality of impairments were sex-specific, no universal patterns emerged that applied to either sex; and (ii) reproduction occurred in all cohorts of impaired females. Moderatelyimpaired flies (e.g. amputation of a single middle leg) laid nearly as many eggs in their lifetime as did intact controls. However, severely impaired flies (i.e. 3 legs amputated) laid significantly fewer eggs.

Biological Journal of the Linnean Society, 2005

An apparent sexual difference in adult feeding behaviour in many species of Lepidoptera relates t... more An apparent sexual difference in adult feeding behaviour in many species of Lepidoptera relates to puddling on mud, dung and carrion. In most butterfly species, puddling is exclusively a male behaviour. A possible explanation for this division in feeding behaviour is that nutrients derived from puddling are transferred to the female in the spermatophore during mating as a nuptial gift. Sodium derived from puddling has been shown to act as a nuptial gift in a few Lepidoptera species. It can also be used for neuromuscular activity in both males and females and may therefore correlate with flight morphology. In this study, we examine the generality of these two hypotheses in comparative work on a community of African fruit-feeding butterflies. We investigated puddling behaviour of males and females on carrion and dung together with sodium preferences, polyandry, relative wing-size, sexual size dimorphism and sodium concentrations in the bodies and spermatophores of several species. The results show that sodium as a nuptial gift can explain the sexual division in puddling in some species, but not in all. Species in which both sexes puddle transfer little sodium in the nuptial gift, which is consistent with the nuptial gift theory. Wing loading and puddling are not significantly correlated, but the trend followed the direction predicted by the activity hypothesis. However, the sodium concentration in the species with the smallest wing area to thoracic volume (WA/TV) ratio (the largest Charaxes spp.), was relatively low. Moreover, in all investigated species, the sodium concentration was higher in the abdomen than in the thorax. The results are discussed in the light of differences between the sexes in foraging behaviour in both larvae and adults, and with respect to alternative explanations for puddling.

Biological Journal of the Linnean Society, 2005

Adult butterflies feed from a variety of substrates and have appropriate adaptations. We examined... more Adult butterflies feed from a variety of substrates and have appropriate adaptations. We examined proboscis morphology in a community of fruit-feeding butterflies (Nymphalidae) in a tropical forest in Uganda. These data were supplemented with behavioural observations and measurements of intake rate on natural and artificial substrates. We found no sexual dimorphism in proboscis morphology even though puddling behaviour is usually performed by males. Two main feeding techniques could be distinguished on the basis of behaviour and morphology: the piercing technique, typically found in Charaxinae, and the sweeping technique employed by both Nymphalinae and Satyrinae. These techniques, distinguished in previous studies, are described in more detail and their relative efficiencies are discussed in the context of sexual dimorphism, food-choice and life history evolution.

Behavioral Ecology and Sociobiology, 2004

The males of butterflies transfer a spermatophore to the female during mating that can contain nu... more The males of butterflies transfer a spermatophore to the female during mating that can contain nutrients enhancing the reproductive potential of their partners. The nutrients transferred by males can be derived from both larval and adult feeding. These nutrients may be depleted by multiple matings. An apparent difference in adult feeding behaviour between the sexes is puddling on mud, dung and carrion, which in most butterfly species is exclusively a male behaviour. A possible explanation for this division in feeding behaviour is that nutrients derived from puddling by males are transferred to the female during mating. Here, we test this hypothesis in the African fruit-feeding butterfly Bicyclus anynana. We varied the male nuptial gift by (1) feeding males either a diet with or without sodium, and (2) varying the number of previous successful copulations by remating males up to five times on consecutive days. The results show both a strong effect of order of mating on the mating duration, and an individual effect with some males typically copulating for a shorter time than others. The effects on female reproduction were, however, minimal. The total number of eggs per female and the sodium content of the eggs did not differ significantly between diets, nor were they affected by the mating histories of the males. Eggs showed a non-significant lower hatching for females partnered by a male who had already mated several times. There was an indication of an interaction with male diet: the sodium treatment showing a decline in egg hatchability with order number of male mating, whilst the control treatment showed a constant hatchability. The results are discussed in relation to determinants of male giftgiving strategy and to other potential explanations for a restriction of puddling to males in butterflies.

Ecology and evolution, 2016

Sexual traits are often the most divergent characters among closely related species, suggesting a... more Sexual traits are often the most divergent characters among closely related species, suggesting an important role of sexual traits in speciation. However, to prove this, we need to show that sexual trait differences accumulate before or during the speciation process, rather than being a consequence of it. Here, we contrast patterns of divergence among putative male sex pheromone (pMSP) composition and the genetic structure inferred from variation in the mitochondrial cytochrome oxidase 1 and nuclear CAD loci in the African butterfly Bicyclus anynana (Butler, 1879) to determine whether the evolution of "pheromonal dialects" occurs before or after the differentiation process. We observed differences in abundance of some shared pMSP components as well as differences in the composition of the pMSP among B. anynana populations. In addition, B. anynana individuals from Kenya displayed differences in the pMSP composition within a single population that appeared not associated wit...

Journal of evolutionary biology, Jan 18, 2016

Both physiologically and ecologically based explanations have been proposed to account for among-... more Both physiologically and ecologically based explanations have been proposed to account for among-species differences in lifespan but they remain poorly tested. Phylogenetically explicit comparative analyses are still scarce, and those that exist are biased towards homoeothermic vertebrates. Insect studies can significantly contribute as lifespan can feasibly be measured in a high number of species, and the selective forces that have shaped it may differ largely between species and from those acting on larger animals. We recorded adult lifespan in 98 species of geometrid moths. Phylogenetic comparative analyses were applied to study variation in species-specific values of lifespan and to reveal its ecological and life-history correlates. Among-species and between-gender differences in lifespan were found to be notably limited; there was also no evidence of phylogenetic signal in this trait. Larger moth species were found to live longer, with this result supporting a physiological rat...

Journal of Biogeography, 2016

Aim Under spatial isolation on oceanic islands, species tend to show extreme body sizes. From the... more Aim Under spatial isolation on oceanic islands, species tend to show extreme body sizes. From the point of view of many colonizers, individual hosts surrounded by phylogenetically distant neighbours are phylogenetically isolated. This study addresses for the first time how phylogenetic isolation of individual hosts affects body size of colonizers, and whether effects on body size reflect selection among colonizers established on host individuals rather than selection among colonizers dispersing toward trees or phenotypic plasticity of colonizers.

Quantification of chemical defence contributes to the study of animal signals, and to understandi... more Quantification of chemical defence contributes to the study of animal signals, and to understanding trade-offs among defences and life history traits. Some tropical fruit-feeding butterfly species can be expected to have well-developed anti-predator defences because they are long-lived, are host-plant specialists, and/or have contrasting colourations that may be involved in mimicry relationships. Yet, as a group they are often assumed to be palatable, even without supporting data. Palatability is a continuum that embraces within and between prey-species variation, and therefore, both among-and within-species variation must be documented. Palatability of nine species of fruitfeeding butterfly in Uganda was rated using a novel assay. One hundred and twenty-five butterflies were homogenized, their ground tissues suspended in sugar water and these suspensions offered as small droplets to individual ants in Petri dishes. The time ants spent feeding on these droplets was measured. Danaine butterflies were used as unpalatable references, and sugar solution as a palatable reference. Ants tended to eat in significantly shorter bouts from danaines compared to fruitfeeding species, and feeding bouts on pure sugar solution were longest. Within fruit-feeding species, variation in the duration of ants' feeding bouts was very substantial. There was also considerable variation among individual ants, such that large sample sizes would be needed to reliably distinguish palatability of different species of fruit-feeding butterflies. In explorative analyses, at least three fruitfeeding butterfly species that were assumed palatable appeared to be chemically defended. These results suggest that, in contrast to common assumptions, some tropical fruit-feeding butterflies use unpalatability for defence, perhaps contributing to their long life spans in the wild.

Biotropica

In communities of tropical insects, adult abundance tends to fluctuate widely, perhaps in part ow... more In communities of tropical insects, adult abundance tends to fluctuate widely, perhaps in part owing to predator-prey dynamics. Yet, temporal patterns of attack rates in tropical forest habitats have not been studied systematically; the identity of predators of insects in tropical forests is poorly known; and their responses to temporal variation in prey abundance have rarely been explored. We recorded incidence and shape of marks of attacks on dummy caterpillars (proxy of predation rate) in a sub-montane tropical forest in Uganda during a yearlong experiment, and explored correlations with inferred caterpillar abundance. Applying the highest and lowest observed daily attack rates on clay dummies over a realistic duration of the larval stage of butterflies, indicates that the temporal variation in attack rate could cause more than 10-fold temporal variation in caterpillar survival. Inferred predators were almost exclusively invertebrates, and beak marks of birds were very scarce. Attack rates by wasps varied more over time than those of ants. Attack rates on dummies peaked during the two wet seasons, and appeared congruent with inferred peaks in caterpillar density. This suggests (1) a functional response (predators shifting to more abundant resource) or adaptive timed phenology (predators timing activity or breeding to coincide with seasonal peaks in prey abundance) of predators, rather than a numerical response (predator populations increasing following peaks in prey abundance); and (2) that predation would dampen abundance fluctuations of tropical Lepidoptera communities.

Books contain sixty-five full color pages with about 200 butterfly species, images of caterpillar... more Books contain sixty-five full color pages with about 200 butterfly species, images of caterpillars, host-plant information particular to Kibale Forest, and including some information that is new to science.

Aterica galene Kiinu ekihoiholya nikirahuka kukyahukaniza ha bindi ebirukusisana Amauris nororra ... more Aterica galene Kiinu ekihoiholya nikirahuka kukyahukaniza ha bindi ebirukusisana Amauris nororra hamapapa gakyo nkoku gekulingirire, Ebisaija biine eraangi eyerukuzoka neyera hamapapa gabyo agenyuma kandi omubikazi eraangi erukweera eburra mu raangi eyerikwiragura n'eraba muraangi yakyenjukyenju (yellowish). Ebikazi bikooto kukira ebisaija, obwokurorraniza na E. pupae, A. galene ine obukarra bwezabu (gold) obutali butonyezi nkobwa Euphaedra. Ekihoiholya kinu kyalika hamuti ogweetwa Pancovia (Omugangara). female uns female ups Catuna crithea Kinu kihoiholya kitaito, kiharukira hansi muno kiine amapapa agahunzirwe nkekiju kyenyamumKinu kihoiholya kitaito, kiharrukira hansi muno kiine amapapa agomumaiso gahunzirwe nkekiju kyenyamumbubi kandi garaihire. Ekihoiholya kinu nikisakusisana ebihoiholya ebindi nka Euphaedra na Bebearia. Ebyaana byebihoiholya binu nibisisanira kimu ebya Euphaedra kandi byalika hamuti ogweetwa Aningeria (omutooke) hamu nahakahurru akeetwa Sycamona afrikana. Biri mukuterana Euriphene ribensis Ebihoiholya ebikazi ebyekika kinu, biine ebirambirambi byeraangi yakyenjukyenju kutandikira hamapapa gabyo agenyuma kugendera kimu nomugomumaiso. Ebisaija biine eraangii ekwasiire ya blue eyekwangasana kandi biiruka mono. Byalika amahuli gabyo hamuti ogweetwa Bersama. female ups male ups female uns Euriphene saphirina Ebihoiholya Binu ebikazi biine ekirambi haiguru yamapapa gabyo agomumaiso kandi ebisaija biine erangi ekwasire kukira eya E. ribensis. Ekihoiholya kinu tikikira kukanya mukibira.

Magazine article in Estonian about the puddling phenomenon in response to a readers question.

meza seems to be Pardaleodes tibullus torensis -but P. bule is also possible. 26 With thanks to T... more meza seems to be Pardaleodes tibullus torensis -but P. bule is also possible. 26 With thanks to Torben Larsen, Steve Collins, Oskar Brattström, Margaret Nyafwono, Niklas Wahlberg and Erki 27 Õunap.

International Journal of Primatology, 2014

Entomologia Experimentalis et Applicata, 2010

The term 'puddling' includes feeding on (dried) mud and various excrements and secretions of vert... more 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.

Entomologia Experimentalis et Applicata, 2011

Reproductive data of individual insects are extremely hard to collect under natural conditions, t... more 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.

Nitrogenous compounds in the adult diet can play an important role in the nutritional ecology and... more Nitrogenous compounds in the adult diet can play an important role in the nutritional ecology and life history evolution of butterflies. We compared the concentration of δ 15N in fruitfeeding butterflies that feed on faeces and carrion (puddling) versus those that do not feed on these substrates, and used the difference between δ 15 N in bodies versus wings as a measure of the amount of nitrogen derived from animals. Differences between the sexes and between the feeding guilds were small, suggesting that minimal amounts of nitrogen were absorbed from these resources. Males, the sex that does most of the puddling, had higher δ 15 N, but this occurred in both carrion feeders and non carrion feeders. This probably reflects differences in metabolic activity of caterpillars. It appears that caterpillar metabolism and metamorphosis results in significant secondary δ 15 N enrichment and differences among the sexes, and, together with host-plant range and quality, in within species variation in δ 15 N values.

Experimental Gerontology, 2009

This study was concerned with the impact of different levels of artificial impairment (leg amputa... more This study was concerned with the impact of different levels of artificial impairment (leg amputations) on male and female survival and female reproduction in the Mexican fruit fly, Anastrepha ludens. We monitored the demographic responses in a total of 100 flies of each sex that were maintained individually in 4 Â 4 Â 10 cm cages and subject to 1-of-11 different leg amputations (plus intact control) including cohorts in which either one front, one middle or one rear leg was severed (3 cohorts total), in which two legs were severed in different front-middle-rear combinations (6 cohorts total), or in which the two middle and one additional leg were severed (2 cohorts total). The two main findings were that: (i) although the effects on mortality of impairments were sex-specific, no universal patterns emerged that applied to either sex; and (ii) reproduction occurred in all cohorts of impaired females. Moderatelyimpaired flies (e.g. amputation of a single middle leg) laid nearly as many eggs in their lifetime as did intact controls. However, severely impaired flies (i.e. 3 legs amputated) laid significantly fewer eggs.

Biological Journal of the Linnean Society, 2005

An apparent sexual difference in adult feeding behaviour in many species of Lepidoptera relates t... more An apparent sexual difference in adult feeding behaviour in many species of Lepidoptera relates to puddling on mud, dung and carrion. In most butterfly species, puddling is exclusively a male behaviour. A possible explanation for this division in feeding behaviour is that nutrients derived from puddling are transferred to the female in the spermatophore during mating as a nuptial gift. Sodium derived from puddling has been shown to act as a nuptial gift in a few Lepidoptera species. It can also be used for neuromuscular activity in both males and females and may therefore correlate with flight morphology. In this study, we examine the generality of these two hypotheses in comparative work on a community of African fruit-feeding butterflies. We investigated puddling behaviour of males and females on carrion and dung together with sodium preferences, polyandry, relative wing-size, sexual size dimorphism and sodium concentrations in the bodies and spermatophores of several species. The results show that sodium as a nuptial gift can explain the sexual division in puddling in some species, but not in all. Species in which both sexes puddle transfer little sodium in the nuptial gift, which is consistent with the nuptial gift theory. Wing loading and puddling are not significantly correlated, but the trend followed the direction predicted by the activity hypothesis. However, the sodium concentration in the species with the smallest wing area to thoracic volume (WA/TV) ratio (the largest Charaxes spp.), was relatively low. Moreover, in all investigated species, the sodium concentration was higher in the abdomen than in the thorax. The results are discussed in the light of differences between the sexes in foraging behaviour in both larvae and adults, and with respect to alternative explanations for puddling.

Biological Journal of the Linnean Society, 2005

Adult butterflies feed from a variety of substrates and have appropriate adaptations. We examined... more Adult butterflies feed from a variety of substrates and have appropriate adaptations. We examined proboscis morphology in a community of fruit-feeding butterflies (Nymphalidae) in a tropical forest in Uganda. These data were supplemented with behavioural observations and measurements of intake rate on natural and artificial substrates. We found no sexual dimorphism in proboscis morphology even though puddling behaviour is usually performed by males. Two main feeding techniques could be distinguished on the basis of behaviour and morphology: the piercing technique, typically found in Charaxinae, and the sweeping technique employed by both Nymphalinae and Satyrinae. These techniques, distinguished in previous studies, are described in more detail and their relative efficiencies are discussed in the context of sexual dimorphism, food-choice and life history evolution.

Behavioral Ecology and Sociobiology, 2004

The males of butterflies transfer a spermatophore to the female during mating that can contain nu... more The males of butterflies transfer a spermatophore to the female during mating that can contain nutrients enhancing the reproductive potential of their partners. The nutrients transferred by males can be derived from both larval and adult feeding. These nutrients may be depleted by multiple matings. An apparent difference in adult feeding behaviour between the sexes is puddling on mud, dung and carrion, which in most butterfly species is exclusively a male behaviour. A possible explanation for this division in feeding behaviour is that nutrients derived from puddling by males are transferred to the female during mating. Here, we test this hypothesis in the African fruit-feeding butterfly Bicyclus anynana. We varied the male nuptial gift by (1) feeding males either a diet with or without sodium, and (2) varying the number of previous successful copulations by remating males up to five times on consecutive days. The results show both a strong effect of order of mating on the mating duration, and an individual effect with some males typically copulating for a shorter time than others. The effects on female reproduction were, however, minimal. The total number of eggs per female and the sodium content of the eggs did not differ significantly between diets, nor were they affected by the mating histories of the males. Eggs showed a non-significant lower hatching for females partnered by a male who had already mated several times. There was an indication of an interaction with male diet: the sodium treatment showing a decline in egg hatchability with order number of male mating, whilst the control treatment showed a constant hatchability. The results are discussed in relation to determinants of male giftgiving strategy and to other potential explanations for a restriction of puddling to males in butterflies.