Effect of Commonly Used Weedicides and Mosquito Larvicides on the Exotic Water Hyacinth Mite, Orthogalumna terebrantis Wallwork (Acarina: Galumnidae)

The toxicity of mosquito larvicides and weedicides commonly used in water hyacinth infested water ways, to exotic water hyacinth mite, Orthogalumna terebrantis Wallwork was determined under laboratory conditions. Among the mosquito larvicides tested, Fenthlon (0.0001%) aud Fenitrothion (0.0002%) were found to be safe to adults. Chlorpyrifos (0.0001%), phenthoate (0.0001%) aad temephos (0.0001%) were mildly toxic to adults, when exposed to sprayed leaf strips, immediately and 24 h after spraying respectively. None of the mosquito larvicides were toxic to the different developmental stages of O. terebrantis. Among the weedicides, 2,4D (0.6%) was found to cause significant mortality (24.63%) of O. terebrantis adults.