Operational Mechanisms of Copulation and Oviposition in Speyeria (Lepidoptera: Nymphalidae)

The morphology and myology of the copulatory and ovipositional mechanisms of Speyeria (Lepidoptera: Nymphalidae) are described, to explain the skeleto-muscular operational mechanisms of copulation and oviposition. The male and female copulatory apparatuses of Speyeria do not have to be appreciably everted to be ready for mating. The male's genitalia are everted by the sequential contraction of the pre-genital segments, and by the dorsal and ventral longitudinal muscles of each segment which also creates an increased intra-abdominal pressure and pushes the hemolymph posterad against the diaphragma. No true morphological ovipositor, nor external genitalia are present in female Speyeria. Thus, the understanding of the copulatory mechanism in the female is based upon the morphology and the manipulative maneuverability of the abdominal segments themselves. The female prepares herself for the reception of the male by raising and retracting the apical portion of her abdomen. This exposes her ostium bursae, which has dilated through the action of six muscle pairs and is ready for the intermittent organ of the male. With the extrusion of the male external genital apparatus, he extends his tegumen and then lowers it with the ankylosed uncus upon the dorsum of the anal papillae. The valves spread laterally, allowing the anal papillae to rest in his membranous fusiform pouches and then extend to securely fix the position of the female. The aedeagus is then introduced into the bursa copulatrix and the vesica exerted as the ejaculate passes through it. At the time of oviposition, a fertilized egg lies in the posterior portion of the membranous common oviduct. Since the female does not possess a true ovipositor, the combined effect of the compression of the anterior segments, the extension of segments IX and X, the increase in intra-abdominal pressure, the peristaltic movements of the oviducts, plus the compression segment VIII, all combine to literally squeeze each egg out of the membranous common oviduct.