G. it. Ent., 5 (29): 351-358
December 31, 1991
The mechanism of sperm transfer in Megaselia scalaris
(Diptera: Phoridae)
by
D. B. BENNER
Abstract - Sperm transfer involving spermatophore-like structures has been reported in families of the Nematocera and in the Schizophora Cyclorrhapha families Drosophilidae and Glossinidae. This report describes a similar mechanism in a member of the Aschiza Cyclorrhapha Phoridae: the species Megaselia scalaris. A sperm aggregate is transmitted to the anterior compartment of the female genital chamber during a 32 second mating. Immediately the sperm mass breaks down and sperm enter the spermatheca. The sperm are contained in a viscous fluid found in the testes. Male accessory gland fluids enter the chamber before the sperm mass, but they remain liquid and surround the sperm mass but form no association with the sperm mass. There is no capsule enclosing the sperm, so this is not a true spermatophore but appears to be a spermatozeugmata, as defined by Mann (1984, Spermatophores). A sperm mass is recovered from the gonopore of many males when matings are interrupted at approximately 15 seconds. If this testis-type system proves to be an automorphy of the Phoridae it may provide a useful character in establishing the phylogeny of the family.
