Consequences of the arms race between <Emphasis Type="Italic">Maculinea teleius</Emphasis> social parasite and <Emphasis Type="Italic">Myrmica</Emphasis> host ants for myrmecophilous butterfly conservation

The arms race between Maculinea butterflies and Myrmica host ants leads to local host-parasite adaptations. In our study, we assessed whether sympatric and allopatric Myrmica scabrinodis populations exhibit behavioural differences towards Maculinea teleius larvae during the adoption-period when butterfly larvae need to be taken inside the Myrmica nest. The second aim was to assess the butterfly survival rate inside ant colonies from different populations. We used one sympatric host population and three allopatric populations: one infested by M. teleius and two uninfested populations. We found that ants from the sympatric population showed a higher number of positive behaviours toward M. teleius larvae during adoption than ants from the allopatric populations. There were no differences in the number of inspection or negative behaviour events. The survival of butterfly larvae was highest inside sympatric host colonies and differed from the survival of M. teleius reared by ants from the allopatric, uninfested populations. No difference was found for the survival rate of M. teleius raised by infested, allopatric host colonies compared to sympatric host populations. Our results suggest the lack of behavioural counter-adaptations of local hosts of M. teleius that more easily adopt and rear butterfly caterpillars compared to naive M. scabrinodis colonies. Our results may also have implications for Maculinea butterfly conservation, especially for reintroduction programmes. We suggest that the existence of behavioural host defences should be checked for the source host population, as well as for the Myrmica population from the reintroduction site. It may also be reasonable to introduce several Myrmica host colonies from the source butterfly host population.     

Persistence in Massachusetts of the veined white butterfly due to use of the invasive form of cuckoo flower

The native pierid butterfly Pieris oleracea underwent a large range reduction in New England in the twentieth century, likely due to the introduction the invasive butterfly Pieris rapae (Lep.: Pieridae) to North America in 1860, and later the oligophagous parasitoid Cotesia glomerata (Hymenoptera: Braconidae) in 1884. Thought extirpated from the state by the 1970s, one large dense population of the butterfly was found in the mid 1980s in a flood plain meadow along the Housatonic River in Lenox, Berkshire Co., Massachusetts. We examined how this native pierid was able to maintain a relatively dense local population by feeding on a novel, invasive host plant, Cardamine pratensis (cuckoo flower), in a meadow habitat despite known parasitoid presence. We approached this question in three ways. First, we deployed trap host plants (cuckoo flower and collards) stocked host larvae (first and second instars of either P. rapae or P. oleracea) at the Lenox site and other locations to determine current rates of C. glomerata attack, for comparison with historical information. Second, we used olfactometer experiments to determine if C. glomerata females could detect the cuckoo flower volatiles released during P. oleracea larval feeding. Third, we used field-cage experiments to determine if the plant architecture found in the flood plain meadow inhibited the ability of C. glomerata females to locate and parasitize hosts. Specifically, we asked if overtopping vegetation prevented or reduced parasitism of P. oleracea larvae feeding on the covered basal rosettes of C. pratensis, which is the physical form of host plant for three of the four butterfly generations at the site.     

Metabolome analysis of food-chain between plants and insects

Evolution has shown the co-dependency between host plants and predators (insects), especially inevitable dependency of predators on plant biomass for securing their energy sources. It was postulated that NAD⁺ source used for major energy producing pathway is the glycerol-3-phosphate shuttle in insects. Using high throughput metabolomics approach, we found that larva of leaf beetle (Gastrophysa atrocyanea), which feed oxalate-rich plants (Rumex obtusifolius), possessed a unique mechanism for accumulating unusually high amounts of lactate. Similarly, larva of butterfly (Papilio machaon) fed with fennel (Foeniculum vulgare) accumulated lactate. Same butterfly also showed the elevated level of glycerol-3-phosphate equivalent to lactate. These evidences provide new insights into the mechanism underlying metabolite alteration between host plants and insect herbivores.     

Observations on the ecology of the endangered butterfly <Emphasis Type="Italic">Zerynthia cassandra</Emphasis> in a protected area of Northern Italy

Zerynthia cassandra is a butterfly endemic to the Italian peninsula. It was recently recognized as a sister species of Zerynthia polyxena. Z. cassandra is oligophagous as it feeds on a very restricted number of toxic plants belonging to the genus Aristolochia: Aristolochia pallida and A. rotunda. The paper reports the results of a research on the ecology of this species which was studied in the natural reserve "Stagni di Lungavilla" (Northern Italy) where the butterfly was living in a small patch of grassy vegetation bordered by a ditch at the margins of a pond. Z. cassandra develops one generation a year. Oviposition occurred in April. Eggs were mainly laid on the lower side of A. rotunda blades. The height of eggs from the ground depended on climatic trends, which affected the host plant phenology. Eggs mortality was mainly due to consumption of leaves by snails (Cepaea nemoralis) and slugs (Arion sp.). Larvae completed their development from April to May, while chrysalises were the aestivating and overwintering stage. Females did not lay eggs on host plants when they were part of the undergrowth. A decline of the butterfly due to habitat changes was recorded during the research (2001–2005). According to information coming from local butterfly watchers the butterfly used to be quite common in the natural reserve until 70’s. Its decline was caused by agricultural intensification and the natural evolution of vegetation towards woodlands, which gradually reduced the host plant density, so making the habitat unsuitable and causing the local extinction of the butterfly.     

Patch occupancy and habitat of the hops azure (<Emphasis Type="Italic">Celastrina</Emphasis><Emphasis Type="Italic">humulus</Emphasis>), a rare North American endemic butterfly: insights for monitoring and conservation

The hops azure (Celastrina humulus Scott & D. Wright 1998) is a rare butterfly found along the Front Range of Colorado. Data on the prevalence of the butterfly and its preferred habitats are lacking. To describe the habitat of C. humulus at the southern part of its range, explore what factors impact C. humulus detectability, and estimate C. humulus habitat use along a riparian area known to support it, we conducted an occupancy analysis along the largest riparian system at the U.S. Air Force Academy (USAFA) in Colorado, USA. We used environmental and site-specific covariates to model the probability of detection and the probability of occupancy. Probability of detecting C. humulus was influenced by the amount of cloud cover during sampling, while the probability of occupancy was influenced by the total area of the host plant (wild hops) at the site. Probability of detection was higher during the first visit (69 %) than the second visit (64 %), and the probability of occupancy was higher (77 %) than assumed (30 %). Despite the host plant being patchily distributed throughout the butterfly’s range, the riparian areas at USAFA had a high prevalence of both wild hops and C. humulus. We use the project findings to develop future sampling efforts for the butterfly along tributaries at other locales within the butterfly’s range.     

Oviposition site selection of the Alcon blue butterfly at the northern range margin

Female oviposition decisions in insects may strongly affect offspring growth and survival, and thus determine population performance. In this study, we examined oviposition site selection in the xerophilous ecotype of the endangered myrmecophilous butterfly Phengaris (=Maculinea) alcon (Lepidoptera, Lycaenidae) in Estonia, at the northern distribution margin of both the butterfly and its host plant, Gentiana cruciata L. Egg distribution on individual host plants appeared to be highly uneven: plants carrying high egg loads contrasted to a high proportion of host plants without any or with a few eggs. Host plant use for oviposition was strongly dependent on plant characteristics and environmental context. Host plant height relative to the surrounding vegetation rather than the absolute height of host plants was a key factor determining the use of particular host plant individuals for oviposition. In particular, plants protruding above surrounding vegetation had a higher probability of being used for oviposition, and carried more eggs. Additionally, the number of eggs laid on individual host plants was positively associated with the presence of flowers and the number of shoots. More aggregated host plants received fewer eggs than those with less conspecifics around. Feeding damage by wild herbivores, found in a substantial proportion of the butterfly’s host plants, strongly reduced the number of eggs on individual plants. Our results underline the need to assure that butterfly’s host plants do not become overgrown by surrounding vegetation. Best practices for opening vegetation around host plants may need further studies that explicitly account for butterfly’s host ants—their abundance in relation to vegetation height and their response to opening vegetation.     

Distribution and Evolutionary Impact of Wolbachia on Butterfly Hosts

Wolbachia are maternally inherited endosymbiotic alpha-proteobacteria found in terrestrial arthropods and filarial nematodes. They are transmitted vertically through host cytoplasm and alter host biology by inducing various reproductive alterations, like feminization, parthenogenesis, male killing (MK) and cytoplasmic incompatibility. In butterflies, some effects especially MK and sperm-egg incompatibility are well established. All these effects skew the sex ratio towards female and subsequently favor the vertical transmission of Wolbachia. Some of the insects are also infected with multiple Wolbachia strains which may results in some complex phenomenon. In the present review the potential of Wolbachia for promoting evolutionary changes in its hosts with emphasis on recent advances in interactions of butterfly–Wolbachia is discussed. In addition to this, strain diversity of Wolbachia and its effects on various butterfly hosts are also highlighted.     

Role of morphological variables of the visitor butterfly species in relation to their foraging behaviour on Lantana camara: Implication for conservation

The study of foraging behaviour of butterflies has been an important focus among the lepidopterists for years. Although established as invasive weed plant, the role Lantana camara as an important host plant as well as a food plant for the butterfly species is now well-known. The present study aims to interpret the role of morphological variables of the visitor butterflies in relation to their foraging behaviour on Lantana camara. Butterflies with longer proboscis were more efficient in foraging on flowers of Lantana camara than the butterflies with shorter ones, when the species containing proboscis same as or longer than their body length were excluded. Longer relative proboscis length (RPL) have selective advantage for foraging over Lantana camara up to a certain point (RPL = 0.881) and after that larger relative proboscis length often obstructs foraging behaviour as the handling time increases and these butterflies face more resistance against incoming nectar than the others.The residuals (body weight-wing span) also act as important factor.The handling time of the butterflies on Lantana camara shows a negative relationship with the residuals. The findings suggests that in case of Lantana camara as a nectaring plant butterfly species with longer proboscis have selective advantage for exploitation of the resource than the species with shorter ones and plantation of Lantana camara may be useful for conserving the long tongued butterfly species.     

Inferring the Provenance of an Alien Species with DNA Barcodes: The Neotropical Butterfly Dryas iulia in Thailand

The Neotropical butterfly Dryas iulia has been collected from several locations in Thailand and Malaysia since 2007, and has been observed breeding in the wild, using introduced Passiflora foetida as a larval host plant. The butterfly is bred by a butterfly house in Phuket, Thailand, for release at weddings and Buddhist ceremonies, and we hypothesized that this butterfly house was the source of wild, Thai individuals. We compared wing patterns and COI barcodes from two, wild Thai populations with individuals obtained from this butterfly house. All Thai individuals resemble the subspecies D. iulia modesta, and barcodes from wild and captive Thai specimens were identical. This unique, Thai barcode was not found in any of the 30 specimens sampled from the wild in the species'' native range, but is most similar to specimens from Costa Rica, where many exporting butterfly farms are located. These data implicate the butterfly house as the source of Thailand''s wild D. iulia populations, which are currently so widespread that eradication efforts are unlikely to be successful.     

Restoration action and species response: oviposition habits of Plebejus icarioides fenderi (Lepidoptera: Lycaenidae) across a restoration chronosequence in the Willamette Valley, Oregon, USA

Habitat restoration is critical to the conservation of rare species. However, restoration efforts often proceed without knowledge of their effects on these species. We investigated the reproductive response of federally endangered Fender’s blue butterfly (Plebejus icarioides fenderi) to prairie restoration in Willamette Valley, Oregon, USA. In 2009 and 2010, we quantified availability of larval host plant, Kincaid’s lupine (Lupinus oreganus), and butterfly oviposition in three restored areas (1–10 years old) and adjacent intact habitat. Oviposition measures in restored areas reached or exceeded intact habitat (0.1 eggs/leaf of host plant and 12 % of time ovipositing) within five years post-restoration. However, none of the restorations provided an equivalent host plant density to intact areas (55 leaves/m²). The different response time of host plants and butterflies to restoration highlights the importance of monitoring both vegetation and oviposition over an ecologically relevant timescale (at least 10 years). For imperiled species, quantifying reproductive response to restoration is critical for adaptive management and successful conservation of the species which restoration efforts are intended to benefit.     

Not only the butterflies: managing ants on road verges to benefit Phengaris (Maculinea) butterflies

Obligate myrmecophilic butterfly species, such as Phengaris (Maculinea) teleius and P. nausithous, have narrow habitat requirements. Living as a caterpillar in the nests of the ant species Myrmica scabrinodis and M. rubra, respectively, they can only survive on sites with both host ants and the host plant Great Burnet Sanguisorba officinalis. After having been reintroduced into a nature reserve in the Netherlands in 1990, both butterfly species expanded their distribution to linear landscape elements such as road verges and ditch edges outside this reserve. As additional habitat of both butterfly species, vegetation management of these landscape elements became important. Our results show that a management beneficial for Phengaris butterflies should aim to increase the nest density of Myrmica species, at the same time reducing the density of nests of the competitor Lasius niger or at least keeping them at a low density. Unfavourable grassland management under which L. niger thrives, includes not mowing or flail-cutting the grass, or depositing dredgings along the side of the ditch. Management favourable for the two Myrmica species differs, demanding some flexibility if both species are to benefit. M. scabrinodis is best supported with early mowing of the road verge vegetation or late mowing in the nature reserve, both of which result in an open vegetation and warm microclimate. In contrast, the nest sites of M. rubra should be left undisturbed during the summer, and mown in late autumn. Mowing of butterfly habitat should be avoided between mid-June and mid-September as this would remove the flowerheads of the Sanguisorba plants, on which the butterflies lay their eggs.     

Restoration of an endangered plant,Hygrophila pogonocalyx,leads to an adaptive host shift of the chocolate pansy (Junonia iphita iphita)

Anthropogenic introduction of a plant species may cause novel encounters between the plant and local herbivores, and initiate evolutionary changes in host plant usage by herbivores. Until recently the endemic aquatic plant Hygrophila pogonocalyx was endangered and had a restricted distribution in Taiwan. Massive restoration efforts since 1997 have led to an expansion of the plant's distribution and a novel encounter between it and an Asian butterfly, the chocolate pansy, Junonia iphita (Nymphalidae). This butterfly appears to have colonized H. pogonocalyx, switching from its original host, Strobilanthes penstemonoides var. formosana. In the present study, we aimed to investigate whether the utilization of H. pogonocalyx as a host plant has initiated a differentiation between butterflies using the novel and the original hosts. To this purpose we collected butterflies from patches of the two host plants which grow sympatrically. We tested oviposition preference for the two hosts and larval performance on them. Female adults exhibited distinct oviposition preference toward the host plant their mothers preferred. Offspring showed greater survivorship and pupal weight when fed on the host plant their mothers preferred. Male adults displayed territorial behaviors on the host plant that their mothers had preferred. Finally, the survival rate of offspring produced from cross-mating between individuals with different host plant preference was lower than that of non-hybrids. Taken together, we suggest that genetic differentiation has occurred between individuals preferring H. pogonocalyx versus S. penstemonoides as host plants via host shifting. This process was likely induced by the mass restoration of the formerly rare and endangered plant species.     

Mitochondrial DNA Sequence Variation of the Swallowtail Butterfly, Papilio xuthus, and the Cabbage Butterfly, Pieris rapae

We analyzed a portion of mitochondrial COI gene sequences (658 bp) to investigate the genetic diversity and geographic variation of the swallowtail butterfly, Papilio xuthus L. (Lepidoptera: Papilionidae), and the cabbage butterfly, Pieris rapae L. (Lepidoptera: Pieridae). Papilio xuthus showed a moderate level of sequence divergence (0.91% at maximum) in 15 haplotypes, whereas Pi. rapae showed a moderate to high level of sequence divergence (1.67% at maximum) in 30 haplotypes, compared with other relevant studies. Analyses of population genetic structure showed that most populations are not genetically differentiated in both species. The distribution pattern of both species appears to be consistent with category IV of the phylogeographic pattern sensu Avise: a phylogenetic continuity, an absence of regional isolation of mtDNA clones, and extensive distribution of close clones. The observed pattern of genetic diversity and geographic variation of the two butterfly species seem to reflect the abundant habitats, abundant host plants, and flying abilities in connection with the lack of historical biogeographic barriers.     

Cycasin in the endangered butterfly Eumaeus atala florida

The strikingly beautiful aposematic hairstreak butterfly, Eumaeus atala florida, its pupa and brightly coloured, gregarious larva, all contain cycasin, the β-D-glucoside of methylazoxymethanol (MAM), which is also present in the food plant. It is suggested that the sequestration and storage of this toxin by the butterfly protects it from potential predators and that its various, highly specialized, warning attributes indicate a long association with the plant host.     

Pathogen invasion triggers an evolutionary trap for an endangered checkerspot butterfly dependent on an exotic host plant

Exotic pathogen invasions can change host eco-evolutionary interactions and possibly create an evolutionary trap when the pathogen generates mismatches between developmental phenology and reproductive cues. Taylor’s checkerspot butterfly (Euphydryas editha taylori), is an endangered species of western North America with 80 % of the extant populations dependent on an exotic host, Plantago lanceolata. Survey of occupied, recently extinct, and unsuccessful butterfly reintroduction sites spanning 4° of latitude revealed widespread disease on P. lanceolata caused by Pyrenopeziza plantaginis. This fungal pathogen, new to North America, reduces the standing crop of P. lanceolata foliage throughout the winter post-diapause larval feeding period. However, disease is absent when adult butterflies and pre-diapause larvae are active. Diseased plants were frequent in Taylor’s checkerspot populations with a history of persistence, but >90 % of the host plants in these populations had initiated new leaves within the first few weeks of post-diapause larval feeding. Conversely, host plants in recently extinct and unsuccessfully reintroduced populations were severely diseased, >66 % mean foliage necrosis/plant, and <23 % had initiated new leaves. Feeding choice trials with 25 larvae indicated that new leaves were strongly and consistently preferred by post-diapause larvae over all other available leaf types, both diseased and non-diseased. Because the influence of disease on post-diapause larval food resources is developmentally disassociated from oviposition, P. plantaginis invasion appears to have triggered an evolutionary trap for Plantago-dependent populations of Taylor’s checkerspot.     

An Evidence for Host Translation Inhibitory Factor Encoded in a Polydnavirus,Cotesia glomerata Bracovirus,Genome and Its Expression in Parasitized Cabbage White Butterfly,Pieris rapae

Polydnavirus is a DNA virus symbiotic to some endoparasitic wasps and plays a critical role in accomplishing successful parasitic life cycle of host wasps. Host translation inhibitory factor (HTIF) has been found in some polydnaviral genomes and performs parasitic functions leading to host immunosuppression and redirecting host nutrient usage to wasp development. The cabbage white butterfly, Pieris rapae, parasitized by a gregarious endoparasitoid, Cotesia glomerata, undergoes several physiological alterations including immune malfunctioning and failure of pupal metamorphosis. C. glomerata possesses its own symbiotic polydnavirus, C. glomerata bracovirus (CgBV). Its genome consisted of at least 12 segments in unequal amounts. Parasitized P. rapae hemolymph contained HTIF-like protein, which was determined through an immunoblotting assay using HTIF antibody of C. plutellae bracovirus (CpBV). RT-PCR using HTIF primers of CpBV produced an HTIF-like gene in P. rapae larvae parasitized by C. glomerata. Also, this HTIF-like gene was encoded in CgBV genome and its partial sequence of CgBV showed highly homology (98.5%) to amino acid sequence of an HTIF of CpBV, called CpBV15a. These results suggest that a common HTIF-like moiety may be shared among Cotesia-associated bracovirus.     

Using a phenological network to assess weather influences on first appearance of butterflies in the Netherlands

Phenological responses of butterflies to temperature have been demonstrated in several European countries by using data from standardized butterfly monitoring schemes. Recently, phenological networks have enabled volunteers to record phenological observations at project websites. In this study, the quality of the first appearance data of butterflies from the Dutch phenological network ‘De Natuurkalender’ was examined and these data were then used to analyze trends in butterfly appearance between 2001 and 2013, the effects of climatic factors on appearance of butterflies as well as the phenological interaction of one butterfly species, Anthocharis cardamines, and its two major host plants. Although phenological networks are relatively unstructured, this study shows that data from De Natuurkalender were highly comparable to more standardized data collected by the Dutch Butterfly Monitoring Scheme. No trend in first appearance of any butterfly species was found during the time period 2001–2013. The first appearance dates of most butterflies showed, however, a clear relationship with spring temperature. Higher temperatures, especially in March and April, advanced the first appearance of butterflies. Therefore, with climatic warming in the future, earlier appearance of butterflies is expected. Although climate warming is a potential threat for phenological mismatches between different trophic levels, this study shows a similar temperature response of A. cardamines and its main host plants in the Netherlands. However, as only few phenological interactions between species are examined, further research including rarer monophagous butterfly species and their host plants is needed.     

Host plant use by the Heath fritillary butterfly, Melitaea athalia: plant habitat, species and chemistry

We present a study of habitat use, oviposition plant choice, and food plant suitability for the checkerspot butterfly Melitaea athalia Rottemburg (Lepidoptera: Nymphalidae) in Åland, Finland. We found that in Åland, unlike in the mainland of Finland and many parts of its range, M. athalia flies mainly in open meadows. When offered an array of plants in a large (32 × 26 m) field cage, they predominately oviposited upon Veronica chamaedrys L., V. spicata L. and Plantago lanceolata L. (Plantaginaceae), which grow in open meadows. The relative abundance of the butterfly in Åland, and its habitat and host plant use there, may reflect local adaptation to land use practices and geology that maintain clusters of small open meadows with little successional change. At the scale of a plant patch, preferred species were used as frequently in mixed species patches as in mono-specific patches, and more oviposition occurred in open than in grassy patches. All of the host plants used by M. athalia are defended by iridoid glycosides (IGs). However, oviposition choice among species and among individual plants within species was largely independent of IG concentration. This contrast with the more discerning congener, M. cinxia, supports the idea that host discrimination decreases with increasing host range. Finally, although the adult butterflies chose specific plant species for oviposition, as larvae they performed well on twelve out of thirteen species of plants, including both known hosts and related novel plants that occur in Åland, indicating a much wider range of larval food plant species than adult oviposition species.     

No seasonal trend in infection of the pale grass blue butterfly, Zizeeria maha (Lepidoptera: Lycaenidae), by Wolbachia

Wolbachia are Gram-negative bacteria that cause intracellular inherited infections in many invertebrates. They are extremely common, with 20–75 % of all insects being infected. Wolbachia belong to taxa of the Anaplasmataceae family, alpha proteobacteria. Because previous studies have shown that Wolbachia generally disappear from the host insect’s body under high-temperature conditions in laboratories, we investigated seasonal changes in infection of the pale grass blue butterfly, Zizeeria maha (Kollar, 1848) by Wolbachia, for 7 months of the year. Total annual infection was 86.7 % (n = 15) of females and 96.3 % (n = 81) of males. Statistical analysis showed that monthly infection was not significantly different among months. In addition, no significant difference was found between Wolbachia densities in cells of summer and winter butterfly samples by use of real-time PCR during the months examined. The results suggest that Wolbachia infection is not affected by seasonal factors, at least for Z. maha.     

Phenological synchrony between a plant and a specialised herbivore

Global anthropogenic climate change is altering the phenology of many species, with implications for interacting species. If species use different cues or respond at different rates, this could result in asynchrony between hosts and herbivores. The larval stage of the endemic critically endangered Sinai Baton Blue butterfly (Pseudophilotes sinaicus) feeds exclusively on the buds and flowers of an endangered near-endemic plant, the Sinai Thyme (Thymus decussatus), with a narrow window in time when both larvae and flowers are present. We test for synchrony in time and space between the flowering phenology of the host plant and the associated timings and abundances of the Sinai Baton Blue. Together with significant spatial variation amongst patches, there were large inter-annual variations in flowering period, up to two weeks between years, indicating phenotypic plasticity in response to abiotic conditions. The butterfly flight period was approximately synchronised to the flowering of its host plant, but there was no evidence of any detailed spatial or temporal correlations in phenology. The dramatic annual population changes, possibly cycles, in the butterfly, may partly be driven by differences in the responses between plant and herbivore to climate that cause varying degrees of synchrony between years.