Taste input from tarsal sensilla is related to egg‐laying behavior in Papilio hospiton

In herbivorous insects, host selection involves various sensory modalities (sight, smell, taste), but the contact chemoreceptors capable of detecting stimuli both from host and non‐host plants play an important role in the final steps of oviposition behavior. Female butterflies scratch and drum the leaf surface and taste the compounds present in plant saps with their tarsal chemosensilla. We assumed that tarsal taste sensitivity may be related to the breadth of host selection in ovipositing females of Papilio hospitonGéné (Lepidoptera: Papilionidae). The spike activity of tarsal taste basiconic sensilla was recorded in response to stimulation with NaCl, bitter compounds, and carbohydrates, with the aim of characterizing the gustatory receptor neurons (GRNs) and of comparing the response patterns in the light of differences in acceptability of host plants. Then we studied the sensitivity of GRNs to saps of the host plants Ferula communis L., Peucedanum paniculatumLoisel, Pastinaca latifolia (Duby) DC. (all Apiaceae), and Ruta lamarmorae Bacch., Brullo et Giusso (Rutaceae), and evaluated the relationship between taste sensitivity and oviposition preference. The results indicate that (1) each sensillum houses sugar‐, bitter‐, and salt‐sensitive cells; (2) the spike activity of the gustatory neurons in response to plant saps produces a different response pattern across all active GRNs; and (3) the number of eggs laid on each plant is highest on F. communis and lowest on R. lamarmorae. These results suggest that the varying activity of the tarsal GRNs may affect host plant acceptability and that ovipositing females of P. hospiton seem to be able to discriminate between host plants.     

Poly modal emergence of the tiger swallowtail, Papilio glaucus (Lepidoptera: Papilionidae): source of a false second generation in central New York State

Abstract. 1. The tiger swallowtail butterfly, Papilio glaucus (L.) (Lepidoptera: Papilionidae), is commonly assumed to have a bivoltine life cycle in central New York State and other parts of the northeastern United States. The seasonal abundance of adults in Tompkins County, New York, shows a bimodal pattern in some years, and a skewed unimodal pattern in others. We studied the incidence of diapause, the potential for successful development of two generations in the field, and the dates of adult emergence from overwintering pupae to determine whether these seasonal patterns are the result of bivoltinism.
2. Insects from Tompkins County, reared as larvae under 16L:8D photoperiod, uniformly enter pupal diapause.
3. Comparison of the heat units required for successful development of two generations with the heat units available in the field during 11 years shows that emergence of non-diapausing individuals would occur too late in the summer to contribute to the second peak of butterfly abundance. Offspring of non-diapausing individuals could only rarely complete development before the end of the growth season.
4. Diapausing offspring of butterflies collected in early June and late July differed sufficiently in dates of emergence to account for the field pattern of seasonal abundance.
5. Electrophoretic studies revealed no evidence of genetic isolation between early and late emerging butterflies.
6. These results suggest that polymodal emergence of diapausing insects can masquerade as a bivoltine life cycle.     

Divergence in larval responses to food plants between temperate and tropical populations of the black swallowtail butterfly

ABSTRACT.

• 1 Larvae of the black swallowtail butterfly, Papilio polyxenes Fabr., from New York and Costa Rica were reared under the same environmental conditions on Daucus carota L. and Spananthe paniculata Jacq. (Umbelliferae), which are the host plants most commonly used by the two populations, respectively. Feeding rates, growth rates and feeding efficiencies of the fifth instar larvae were measured by standard techniques.
• 2 Larvae from each population grew faster on the host-plant species from their region of origin than did larvae from the other population, though differences on S.paniculata were not significant. On D.carota the faster growth by New York larvae was attributable to greater efficiency. On S.paniculata, by contrast, the somewhat faster growth by Costa Rican larvae seemed to have resulted chiefly from faster feeding. The two populations have thus come to differ in metabolic and, probably, behavioural responses to host plants.
• 3 S.paniculata was a superior host plant for larvae of both populations, even though the total energy, nitrogen and water content of its foliage was similar to that of D.carota.
• 4 These results are consistent with the hypothesis that insects in the two populations have diverged in adaptation to their host plants following curtailment of gene flow between them as the species colonized Central America from the north.

     

The cladistics and biology of the Callajoppa genus-group (Hymenoptera: Ichneumonidae, Ichneumoninae)

A cladistic analysis is presented for the genera of the former ichneumonine tribe Trogini. The tribe Heresiarchini is paraphyletic with respect to the Trogini, and so maintaining Trogini as a separate tribe is unsatisfactory. Within Heresiarchini, the following changes are made: (a) the subtribes Apatetorina and Heresiarchina are referred to as the Apatetor and Heresiarches genus‐groups, (b) the genera of the paraphyletic subtribe Protichneumonina are treated as incerta sedis within Heresiarchini, and (c) the Trogini are referred to as the Callajoppa genus‐group, with the former subtribe Trogina referred to as the Trogus subgroup. Thirty‐five genera are recognized as valid within the Callajoppa genus‐group. Catadelphops, Catadelphus, Cobunus, and Facydes are transferred to this group; Holojoppa is removed and is incertae sedis within Heresiarchini. Three new synonyms are proposed: Araeoscelis and Cryptopyge are junior synonyms of Macrojoppa, and Neamblyjoppa is a junior synonym of Catadelphops. Trogus latipennis Cresson is transferred to Pedinopelte from Macrojoppa, and Trogus mactator Tosquinet and its related species (T. bicolor Radoszkowski, T. heinrichi Uchida, and T. tricephalus Uchida) are transferred to Holcojoppa. Tricyphus is redefined and a neotype is designated for Tricyphus cuspidiger Kriechbaumer, the type‐species of the genus. Thirteen new genera are described (authorship of all is Wahl & Sime): Charmedia (type‐species: Charmedia chavarriai Wahl & Sime, sp. n.) , Daggoo (type‐species: Daggoo philoctetes Wahl & Sime, sp. n.), Dothenia (type‐species: Dothenia hansoni Wahl & Sime, sp. n.), Humbert (type‐species: Humbert humberti Wahl & Sime, sp. n.), Laderrica (type‐species: Laderrica feenyi Wahl & Sime, sp. n.), Mokajoppa (type‐species: Tricyphus respinozai Ward & Gauld), Metallichneumon (type‐species: Metallichneumon neurospastarchus Wahl & Sime, sp. n.), Myocious (type‐species: Myocious orientalis Wahl & Sime, sp. n.) , Quandrus (type‐species: Trogus pepsoides Smith, transferred from Callajoppa), Queequeg (type‐species: Gathetus flavibasalis Uchida, transferred from Neofacydes), Saranaca (type‐species: Trogus elegans Cresson; includes Trogus apicalis Cresson, Tricyphyus ater Hopper, and Tricyphus floridanus Heinrich), Tashtego (type‐species: Tashtego janzeni Wahl & Sime, sp. n.), and Xanthosomnium (type‐species: Xanthosomnium froesei Wahl & Sime, sp. n.). A key to the genera of the Callajoppa genus‐group is provided. The evolution of biological traits within the Callajoppa genus‐group is discussed with reference to the elucidated phylogeny. The groundplan biology is parasitism of Sphingidae, with oviposition into a host pupa/prepupa. There have been two transitions to butterfly parasitism within the Trogus subgroup: one a transition to Papilionidae (followed by a switch to Nymphalidae at Psilomastax) and the other to Nymphalidae (followed by a switch to Papilionidae within Macrojoppa). ©2002 The Linnean Society of London. Zoological Journal of the Linnean Society, 134 , 1–56.     

Irregular diapause, apparency and evaluating conservation status: anomalies from the Australian butterflies

Examples of irregular development (diapause regimes) are reported in three families (Lycaenidae, Nymphalidae, Papilionidae) of butterflies in Australia. The importance of understanding such irregularities is emphasized, and their relevance to interpreting conservation status and needs discussed. Expectations of incidence or abundance may not be met, and unexpected declines or losses resulting from irregular diapause can cause unnecessary conservation concerns.     

Host plant odor extracts with strong effects on oviposition behavior in Papilio polyxenes

Ovipositing females of the black swallowtail butterfly, Papilio polyxenes Fabricius (Lepidoptera: Papilionidae: Papilioninae), have an innate response to contact chemical cues, but it was not known how naïve females would respond to volatile host plant chemicals. Naïve and experienced females were tested in a free-flight experiment using model plants and volatile extracts from two hosts, carrot [ Daucus carota L. (Apiaceae)] and poison hemlock [ Conium maculatum L. (Apiaceae)], and one non-host, fava bean [ Vicia faba L. (Fabaceae)]. Naïve females responded to both host plant extracts with more approaches and landings than to non-host extracts, with poison hemlock receiving more responses than carrot. Females experienced with one of the two host plants also approached and landed frequently on extracts of host plants, but poison hemlock again received more approaches and landings, regardless of a female's host plant experience. Female P. polyxenes thus respond specifically to volatile extracts of their host plants, even in the absence of both relevant contact chemical cues and adult host plant experience.     

Independent gene phylogenies and morphology demonstrate a malagasy origin for a wide-ranging group of swallowtail butterflies

Madagascar is home to numerous endemic species and lineages, but the processes that have contributed to its endangered diversity are still poorly understood. Evidence is accumulating to demonstrate the importance of Tertiary dispersal across varying distances of oceanic barriers, supplementing vicariance relationships dating back to the Cretaceous, but these hypotheses remain tentative in the absence of well-supported phylogenies. In the Papilio demoleus group of swallowtail butterflies, three of the five recognized species are restricted to Madagascar, whereas the remaining two species range across the Afrotropical zone and southern Asia plus Australia. We reconstructed phylogenetic relationships for all species in the P. demoleus group, as well as 11 outgroup Papilio species, using 60 morphological characters and about 4 kb of nucleotide sequences from two mitochondrial (cytochrome oxidase I and II) and two nuclear (wg and EF-1alpha) genes. Of the three endemic Malagasy species, the two that are formally listed as endangered or at risk represented the most basal divergences in the group, while the more common third endemic was clearly related to African P. demodocus. The fifth species, P. demoleus, showed little differentiation across southern Asia, but showed divergence from its subspecies sthenelus in Australia. Dispersal-vicariance analysis using cladograms derived from morphology and three independent genes indicated a Malagasy diversification of lime swallowtails in the middle Miocene. Thus, diversification processes on the island of Madagascar may have contributed to the origin of common butterflies that now occur throughout much of the Old World tropical and subtemperate regions. An alternative hypothesis, that Madagascar is a refuge for ancient lineages resulting from successive colonizations from Africa, is less parsimonious and does not explain the relatively low continental diversity of the group.     

CLIMBER: Climatic niche characteristics of the butterflies in Europe

Detailed information on species’ ecological niche characteristics that can be related to declines and extinctions is indispensable for a better understanding of the relationship between the occurrence and performance of wild species and their environment and, moreover, for an improved assessment of the impacts of global change. Knowledge on species characteristics such as habitat requirements is already available in the ecological literature for butterflies, but information about their climatic requirements is still lacking. Here we present a unique dataset on the climatic niche characteristics of 397 European butterflies representing 91% of the European species (see Appendix). These characteristics were obtained by combining detailed information on butterfly distributions in Europe (which also led to the ‘Distribution Atlas of Butterflies in Europe’) and the corresponding climatic conditions. The presented dataset comprises information for the position and breadth of the following climatic niche characteristics: mean annual temperature, range in annual temperature, growing degree days, annual precipitation sum, range in annual precipitation and soil water content. The climatic niche position is indicated by the median and mean value for each climate variable across a species’ range, accompanied by the 95% confidence interval for the mean and the number of grid cells used for calculations. Climatic niche breadth is indicated by the standard deviation and the minimum and maximum values for each climatic variable across a species’ range. Database compilation was based on high quality standards and the data are ready to use for a broad range of applications.It is already evident that the information provided in this dataset is of great relevance for basic and applied ecology. Based on the species temperature index (STI, i.e. the mean temperature value per species), the community temperature index (CTI, i.e. the average STI value across the species in a community) was recently adopted as an indicator of climate change impact on biodiversity by the pan-European framework supporting the Convention on Biological Diversity (Streamlining European Biodiversity Indicators 2010) and has already been used in several scientific publications. The application potential of this database ranges from theoretical aspects such as assessments of past niche evolution or analyses of trait interdependencies to the very applied aspects of measuring, monitoring and projecting historical, ongoing and potential future responses to climate change using butterflies as an indicator.