Sexual selection is thought to result in an elongation of genitalia in insects. Part of the genitalia of the leaf beetle Lema (Lema) coronata Baly is approximately twice the body length in both sexes. Nine microsatellite loci were isolated from L. (L.) coronata for use in future studies on the correlation between genital length and reproductive success. The nine loci were polymorphic, with three to six alleles per locus recorded in 40 individuals. Observed heterozygosity ranged from 0.08 to 0.38 and expected heterozygosity from 0.51 to 0.75. The non-exclusive probability of the second parent and the identity calculated from the set of loci were 0.011 and < 0.001, respectively. A deviation from the Hardy-Weinberg equilibrium was detected at all nine loci, i.e. significant heterozygote deficiencies, and several hypotheses accounting for this are discussed. The isolated loci carried independent information. Five polymorphic loci were amplified in a related sympatric species, L. (L.) scutellaris, which has relatively short genitalia. These microsatellite makers will be used to determine the paternity of offspring of females multiply mated in the laboratory and compare the selection pressures operating on genital length in these closely related species. and Yoko Matsumura, Izumi Yao.
Insect genital characters are extensively used in species level taxonomy, and their value in species delimitation is great. Based on the lock-and-key hypothesis and that genital differences function as a mechanical isolation system between species, the value of genital characters has been thought to be superior to non-genital characters. Although geographical and other kind of intraspecific variation of genitalia is often assumed very moderate, its real extent is insufficiently investigated. We examined patterns of morphological variation in the male genitalia of the tortricid moth Pammene luedersiana, using geometric morphometric tools including thin-plate spline deformation grids, and found significant variation. This variation is continuous both within and between populations. No systematic shape variation was observed between populations, but genital size showed some geographic variability. The results suggest that genital morphology is not constant and should therefore be used with caution in lepidopteran taxonomy.