Effects of plant odor on oviposition by the black swallowtail butterfly,Papilio polyxenes (Lepidoptera: Papilionidae)

Black swallowtail females laid more eggs on plant models treated with contact stimulants and volatiles from carrot leaves than on models treated only with contact stimulants. The volatiles enhanced landing rates and females alighted more frequently on artificial leaves treated with host volatiles than on adjacent control leaves. Volatiles from cabbage, a nonhost, inhibited landing rates on artificial leaves treated with carrot contact stimulants. Examination of antennae revealed two major types of sensilla, believed to be olfactory in function. Electroantennogram preparations responded more strongly to carrot volatiles than to cabbage volatiles and several shared responses at particular retention times to carrot volatile components eluting from a gas chromatograph. Our results are consistent with a long-standing hypothesis that behavioral responses to essential oil components characteristic of the larval food plants have facilitated host shifts in the genus Papilio.     

Characterization of 17 polymorphic microsatellite loci in the Anise swallowtail,Papilio zelicaon (Lepidoptera: Papilionidae), and their amplification in related species

Fifteen polymorphic dinucleotide and two trinucleotide microsatellite loci were identified in the Anise swallowtail, Papilio zelicaon, from DNA genomic libraries enriched for simple sequence repeats. Allele numbers varied from eight to 29, with an excess of homozygotes observed for nine loci. This homozygosity is a feature of other lepidopteran microsatellites and is probably due to null alleles. Sixteen markers were amplified successfully in other representatives of Papilio with 11 loci retaining polymorphism in at least one species. These results suggest that the microsatellites reported here may be appropriate for measuring population genetic structure in a number of Papilio species.     

The effect of ejaculate mass on female reproductive output in the european swallowtail butterfly,Papilio machaon (L.) (Lepidoptera: Papilionidae)

Previously, we showed that virgin males of Papilio machaondeliver ejaculates that are twice as big as any ejaculates they transfer at later matings. Here, we investigate the consequences of these two size classes of ejaculates on female reproductive output and demonstrate that females that received one small ejaculate laid as many eggs, fertilized the same proportion of eggs, and lived as long as those that had received one big ejaculate. However, females that received big ejaculates laid heavier eggs, but only between the twelfth and the fifteenth days of egg-laying. We conclude that male-derived nutrients appear to have a limited effect on female reproductive output in P. machaonand that the large size of ejaculates delivered by male butterflies are determined primarily by selection on males to produce longer refractory periods in females.     

Geographical variability in, and temperature effects on, the phenology of Maniola jurtina and Pyronia tithonus (Lepidoptera, Satyrinae) in England and Wales

ABSTRACT. 1. Geographical variability in, and temperature effects on, the mean date of adult flight period and the SD about this date are analysed for two univoltine, grassland butterflies in England and Wales from 1976 to 1985. Data were collected on the Butterfly Monitoring Scheme for Maniola jurtina (L.) at twenty-nine sites and Pyronia tithonus (L.) at twenty sites.
2. Substantial variability for mean date and SD occurs between years and between sites. Changes in mean date between years tend to occur consistently at different sites. The species show some parallel in variation between sites, especially for mean date.
3. June maximum temperature accounts for 95% and 75% of the variation in mean date between years in M. jurtina and P. tithonus , respectively ( r =-0.97 and -0.87). Similar relationships occur for temperatures cumulated over the period of post-winter development from March to July or August.
4. Greater geographical variability in phenology, and a generally less synchronized flight period in M.jurtina may be associated with broader habitat preferences than in P. tithonus.
5. The mean date of adult flight period remains at roughly the same date at more northerly latitudes. In M.jurtina the flight period becomes more synchronized, begins later and ends earlier in the north. P. tithonus shows little or no indication of such a response to latitude. This is discussed with regard to changes in season length and factors limiting the species'range.