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Nymphalid Butterflies (nymphalid + butterfly)
Selected AbstractsPresence of a cerebral factor showing summer-morph-producing hormone activity in the brain of the seasonal non-polyphenic butterflies Vanessa cardui, V. indica and Nymphalis xanthomelas japonica (Lepidoptera: Nymphalidae)INSECT SCIENCE, Issue 2 2009Ayuki Tanaka Abstract Three species of nymphalid butterflies, Vanessa cardui, V. indica and Nymphalis xanthomelas japonica, do not exhibit seasonal polyphenism in wing coloration. To determine whether seasonal non-polyphenic butterflies possess a cerebral factor affecting wing coloration, we used a Polygonia c-aureum female short-day pupal assay for detection of summer-morph-producing hormone (SMPH) activity in P. c-aureum. When 2% NaCl extracts of 25 brain-equivalents prepared from the pupal brains of V. cardui, V. indica or N. xanthomelas japonica were injected into Polygonia female short-day pupae, all recipients developed into summer-morph adults with dark-yellow wings, and the average grade score (AGS) of summer morphs showing SMPH activity was 3.8, 3.7 and 4.0, respectively. In contrast, when acetone or 80% ethanol extracts prepared from pupal brains were injected into Polygonia pupae, all recipients developed into autumn-morph adults with a dark-brown coloration and each exhibited an AGS of less than 0.5. Our results indicate that a cerebral factor showing SMPH activity is present in the pupal brain of seasonal non-polyphenic nymphalid butterflies, suggesting that a SMPH and cerebral factor showing SMPH activity occur widely among butterfly species. This finding will improve our understanding of the presence of cerebral factors showing interspecific actions of SHPH. [source] Proboscis morphology and food preferences in nymphalid butterflies (Lepidoptera: Nymphalidae)JOURNAL OF ZOOLOGY, Issue 1 2001H. W. Krenn Abstract Many species of nymphalid butterflies only exceptionally visit flowers and feed instead on tree sap, juice of rotting fruits and other decaying substances. To investigate whether the proboscis morphology of these non-flower-visiting Nymphalidae differs from that of nectarivorous butterflies, representatives from 64 nymphalid species with known feeding preferences were examined. Morphometric comparison of the proboscis revealed characteristic differences in proboscis length, tip-region length, wall composition, and number and shape of proboscis sensilla between these two feeding guilds. The investigated non-flower-visiting species belonging to Apaturinae, Limenitidinae, Morphinae, Brassolinae, Nymphalinae and Satyrinae, possess a relatively short and light-coloured proboscis which has a long tip-region with a great number of club-shaped sensilla styloconica. Densely arranged, these sensilla form a flat brush located laterally from the openings into the food canal on the dorsal side of the tip-region. Among the non-flower-visiting species, a second type of proboscis was found in fruit-feeding Charaxinae the stout tip-region of which is equipped with more widely spaced sensilla styloconica. The investigated flower-visiting Heliconiinae, Nymphalinae, Satyrinae, Danainae and Ithomiinae are characterized by a slender, darker-coloured proboscis with a rather short tip-region bearing fewer sensilla styloconica in a loose arrangement. Discriminant analysis revealed that the tip-region length, the number of sensilla styloconica and the relative proboscis length are the most important discriminating variables between the flower-visiting and the non-flower-visiting species. The proboscis morphology of nymphalid butterflies corresponds with certain feeding habits and allow us to make predictions on their food preferences. The ,brush-tipped' proboscis seems to have a functional role in the accumulation of fluid and the uptake of liquid from wet surfaces such as rotting fruits or tree sap. We conclude from the phylogeny of the examined taxa that this derived proboscis tip morphology evolved several times independently as an adaptation to the exploitation of new food resources. [source] Identification of feeding attractants in oak sap for adults of two nymphalid butterflies, Kaniska canace and Vanessa indicaPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2000Hisashi Ômura Abstract The active compounds of oak-sap odour in attracting adults of two butterflies, Kaniska canace (L.) and Vanessa indica (Herbst) (Lepidoptera: Nymphalidae), were identified by chemical analyses, electroantennogram (EAG) and two behavioural assays: proboscis extension reflex (PER) and attraction to artificial tree models. Fourteen compounds were identified from two sap samples collected in 1997 and 1998, of which the major volatiles were ethanol and acetic acid (, 900 p.p.m. and 500 p.p.m. in sap, respectively). However, the chemical composition of the minor volatiles varied considerably between the two samples. Among 13 chemicals tested, V. indica showed strong PER to five aliphatic acids (acetic, propionic, butyric, isobutyric and isovaleric), 2-methylpropan-1-ol and 3-hydroxybutan-2-one, whereas the PER-active compounds for K. canace were these seven compounds and also ethanol, 3-methylbutan-1-ol and 1-hydroxypropan-2-one. In two-choice behavioural bioassays, the model scented with a sap-odour mimic, which was an aqueous mixture of the PER-active compounds, was more attractive to the two butterflies than an unscented control. These results demonstrated that the sap odour stimulates foraging behaviour of the butterfly. Although EAG responses of both butterflies to 3-methylbutan-1-ol and that of V. indica to 2-methylpropan-1-ol were positively dose-dependent, responses to other compounds were not strong and not dose-dependent at 1,100 ,g doses. These EAG responsiveness suggests that the olfactory receptors for these compounds might be few in the antenna and that the butterflies have enough olfactory sensitivity to the dose of 1 ,g. [source] Do canal-cutting behaviours facilitate host-range expansion by insect herbivores?BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009DAVID E. DUSSOURD According to the escalation,radiation model of co-evolution, insect herbivores that acquire the ability to circumvent a plant defence enter a new adaptive zone and increase in species. How herbivore counter-adaptations to plant defences might lead to speciation is poorly understood. Studies of nymphalid butterflies suggest that the evolution of a broadened host range may be a critical step. This paper examines if leaf-feeding insects capable of deactivating defensive plant canals with canal cutting often have broad host ranges. A total of 94 species of canal-cutting insects were identified from the literature, including eight new canal cutters described in this paper. Only 27% of canal cutters with known host ranges are generalists that feed on plants in multiple families. The proportion of generalist canal cutters is similar or lower than estimates of generalists among phytophagous insects overall. Only five species, at most, of the canal-cutting generalists feed exclusively on plants with secretory canals. The paucity of generalists can be attributed in part to the considerable taxonomic distance separating canal-bearing plant families and to their corresponding chemical distinctiveness. The dependence of many canal-cutting species on host chemicals for defence would also favour specialization. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 715,731. [source] | ||||||||||