RESUMO
Dione (Agraulis) dodona (Nymphalidae: Heliconiinae) is a butterfly restricted to the western slopes of the Andes of Peru and Chile and is associated with Malesherbia tenuifolia in xerophytic environments. In this study, we found six additional species of host plants for D. (A.) dodona belonging to the genus Malesherbia (Passifloraceae). We used mitochondrial DNA sequences (COI) and microsatellites to screen genetic variation and investigate population structure in six geographic disjointed populations of D. (A.) dodona associated with distinct Malesherbia species. The PCoA analysis based on allele frequencies evidenced a lack of differentiation among populations and a low FST. The Bayesian cluster analyses revealed the existence of three genetically distinct groups, but almost all individuals present an admixture ancestry. An absence of isolation by distance pattern was observed. Possible scenarios are discussed: a bottleneck or recent colonization from interconnected populations from the south, and ongoing gene flow among local populations by high dispersal through a landscape formed of isolated populations of Malesherbia.
RESUMO
Signa are sclerotized structures located on the inner wall of the corpus bursa of female Lepidoptera whose main function is tearing open spermatophores. The sexually antagonistic coevolution (SAC) hypothesis proposes that the thickness of spermatophore envelopes has driven the evolution of the females signa; this idea is based in the fact that in many lepidopterans female sexual receptivity is at least partially controlled by the volume of ejaculate remaining in the corpus bursa. According to the SAC hypothesis, males evolved thick spermatophore envelopes to delay the post-mating recovery of female sexual receptivity thus reducing sperm competition; in response, females evolved signa for breaking spermatophore envelopes faster, gaining access to the resources contained in them and reducing their intermating intervals; the evolution of signa, in turn, favored the evolution of even thicker spermatophore envelopes, and so on. We tested two predictions of the SAC hypothesis with comparative data on the thickness of spermatophore envelopes of eleven species of Heliconiinae butterflies. The first prediction is that the spermatophore envelopes of polyandrous species with signa will be thicker than those of monandrous species without signa. In agreement with this prediction, we found that the spermatophore envelopes of a polyandrous Heliconius species with signa are thicker than those of two monandrous Heliconius species without signa. The second prediction is that in some species with signa males could enforce monandry in females by evolving "very thick" spermatophore envelopes, in these species we predict that their spermatophore envelopes will be thicker than those of their closer polyandrous relatives with signa. In agreement with this prediction, we found that in two out of three comparisons, spermatophore envelopes of monandrous species with signa have thicker spermatophore envelopes than their closer polyandrous relatives with signa. Thus, our results support the idea that selective pressures arising from sexually antagonistic interactions have been important in the evolution of spermatophore envelopes, female signa and female mating patterns.
RESUMO
The external features of egg, larva and pupa of Dryas iulia alcionea (Cramer, 1779) are described and illustrated.
RESUMO
The external features of egg, larva and pupa of Dryas iulia alcionea (Cramer, 1779) are described and illustrated.
RESUMO
The external features of egg, larva and pupa of Dryas iulia alcionea (Cramer, 1779) are described and illustrated.