Breeding of Ornidia obesa (Diptera: Syrphidae: Eristalinae) on Pig Carcasses in Brazil

On Mho obesa F. (Diptera: Syrphidae) is usually neglected in forensic entomology, although adults are rather frequent on vertebrate carrion. In this study, conducted in southeastern Brazil in 2008, we used two pig carcasses, one killed by cocaine overdose and the other by shooting, to evaluate mainly the possible influences of the type of death on the larval development of O. obesa in the pig remains. We recorded the breeding of 218 adult specimens of this syrphid fly from the carcass killed by shooting, and none from the carcass killed by cocaine. These observations may open a new perspective for the use of O. obesa in forensic studies, considering its breeding preferences and its complete development on vertebrate carrion.

Reproductive biology and pollination of Govenia utriculata: A syrphid fly orchid pollinated through a pollen-deceptive mechanism

The reproductive biology and pollination mechanisms of Govenia utriculata (Sw.) Lindl. were studied in a mesophytic semideciduous forest at Serra do Japi, south-eastern Brazil. The floral visitors and pollination mechanisms were recorded, and experimental pollinations were carried out to determine the breeding system of this species. Populations of G. utriculata growing at Serra do Japi are exclusively visited and pollinated by two species of hoverflies in the genus Salpingogaster (Diptera: Syrphidae) that are attracted by deceit to the flowers of this orchid species. The lip apex and the column base present small brownish and yellow to orange spots that mimic pollen clusters. Govenia utriculata is self-compatible, but pollinator dependent. Natural fruit set was low (10%), but similar to that of other non-obligatorily autogamous sympatric orchid species that occur at Serra do Japi and of other fly-pollinated orchid species pollinated through deceptive mechanisms.