The behavior and natural history of Hybosciara gigantea (Diptera: Sciaridae).
Eberhard W. G., Flores C.
Author Affiliation: Smithsonian Tropical Research Institute, Roosevelt Ave. Ancon, Balboa - Tupper Building, P.O. Box 2072, Panama.
Journal of the Kansas Entomological Society 75 : 8-15
Abstract : Observations were made between November 1999 and March 2000 in second growth and open pastures near San Antonio de Escazu, Costa Rica. Larvae of Hybosciara gigantea fed on leaf litter and formed compact masses of up to several hundred individuals. Larvae in captivity fed on the stalk of a broken stamen of a cas (Psidium friedrichsthalianum) flower, and on a dead larvae from the same mass. They also appeared to feed on fungi on a dead leaf. Sex ratios were often highly biased, and varied widely in different masses. Many males and females in the field had pollen grains scattered over their bodies, indicating that they had visited flowers, presumably to drink nectar. The crops of some females collected on mango flower were swollen with clear liquid. Given the fact that in some sciarid species females are able to produce only a single sex of offspring, larvae in masses were probably often siblings; several other aspects of the flies's natural history were in accord with this hypothesis. Young adult females, but apparently not males, dispersed long distances. Males formed loose ephemeral swarms near vegetation where copulation occurred.