Copulatory Apparatus and Deposition of Male Accessory Secretion in Phormia regina (Diptera: Calliphoridae)

Abstract

A component of the male accessory gland secretion, injected during mating, was responsible for onset of refractory behavior in the female black blow fly, Phormia regina (Meigen). Immediately after mating, two components of the semen were located separately in the bursa copulatrix: sperm were found anteriorly near the opening to the spermathecal ducts, and accessory secretion distended the posterior of the bursa. The accessory secretion disappeared within a day of mating, presumably entering the hemolymph from where it was detected. Scanning electron microscopy of the intromittent organ and phallosome, and reconstruction of the female reproductive tract from serial sections revealed complementary structures in the male and female. A pair of conspicuous flaps on the phallosome clasp a cuticular tonsil in the female, sealing the accessory secretion in the bursa during copulation. Accessory secretion is released at the tip of the phallosome and is redirected to a more proximal release site on the phallosome via a pair of hitherto undescribed accessory ducts, resulting in its deposition posteriorly in the bursa lumen.