Seasonal yeast compositions in Forcipomyia taiwana (Diptera: Ceratopogonidae)

Forcipomyia taiwana, a biting midge, is one of the most annoying blood-sucking pests in Taiwan. The larvae of Forcipomyia species feed primarily on algae, and the adults feed on nectar for nutrition. After mating with male adults, females bite humans and digest blood for the formation and development of their eggs. The bites often cause human itching, swelling, skin lesion and even fatal shock. Harassment from this biting pest has become a serious problem and has influenced the quality of outdoor recreational activities. Thus, it is necessary to understand the ecology of F. taiwana to develop an effective control strategy. This study showed the seasonal variation of yeast compositions in the interior of F. taiwana. Furthermore, we found that Aureobasidium spp. appeared the most during collection times and these yeasts are able to decompose the cellulose, a major component in the cell wall of algae and Oomycete fungi. These fungi infect a broad range of host and have adverse effect on fitness of the biting midges. Thus, Aureobasidium spp. play a crucial role in the defense system of F. taiwana against pathogens. The study provides useful information that could be used in the development of biocontrol strategy in the future.