Trichomycetes constitute a cosmopolitan group of filamentous fungi which are obligate symbionts in the digestive tracts of arthropods. Although this relationship in most species is apparently of a commensalistic nature, at least one species of Smittium has been reported as pathogenic. This study was conducted to determine the level of infestation of S. culisetae in mosquito larvae in the central region of Costa Rica, and to detect other parasites of this medically important group of insects during 1998-2001. Larvae were reared using standard entomological techniques to obtain adults for taxonomic identification; third and fourth stage larvae were dissected to reveal gut contents. A total of 27 mosquito species were collected. The infestation rate in 670 larvae examined was 25.8% which is similar to findings in other areas. Infested larvae did not show any pathological symptoms nor were other parasites of mosquitoes found.

Trichomycetes; Smittium culisetae ; mosquito larvae; Costa Rica; infestation rate