Gynandromorphism and its manifestations in Diprionid Hymenoptera.
Gynandromorphism is a phenomenon which entails the simultaneous presence of phenotypically and genotypically male and female tissues in the same organism. The phenomenon probably results from anomalous oogenesis or fecundation or from cytogenetic aberrations during embryogenesis, and would appear to be favoured by atypical developmental conditions and consanguinity. Three new individuals of Neodiprion sertifer are described. The distribution of male, female, intermediate tissues and of malformations in the body of these individuals and in another eight gynandromorph specimens of the Diprionids family, is examined. The different types of tissues are symmetrically distributed on the right and left sides of the body, but male tissues are more frequently found in the head, a fact which suggests a polarity. The phenomenon is also often associated with malformations apparently limited to the genitalia. Individuals prevalently comprising female tissues but with male antennae were be able to detect a source of synthetic female sexual pheromone.