Insecticidal control of Bemisia tabaci (Hemiptera: Aleyrodidae) transmitting Carlavirus on soybeans and detection of the virus in alternate hosts.
A Carlavirus transmitted by Bemisia tabaci (Gennadius), (Hemiptera: Aleyrodidae), is an important disease of soybean nurseries in Puerto Rico causing substantial germplasm loses. Insecticide bioassay experiments were conducted at Dow AgroSciences (DAS) Research Station, Santa Isabel, Puerto Rico, either by spraying insecticides on B. tabaci infested soybean leaves or introducing B. tabaci adults onto insecticide sprayed soybean leaves. Moreover, host plants were surveyed to detect the virus in overwintering hosts that serve as source of inoculums. The direct spray experiment showed that Nuprid 2F (Imidacloprid), Capture 2 EC (Bifenthrin), Thionex (Endosulfan), Lannate LV (Methomyl), and Dimethoate gave good level (>80%) of control of B. tabaci. However, in the second set of the bioassay test, the residual activity of all of the insecticides was generally low. Except Thionex, all the insecticides resulted in less than 50% mortality on adult B. tabaci that were introduced 24 h after spray. The host plant survey showed that 8 out of the 18 commonly occurring plant species gave positive result to the Enzyme-linked immunosorbent assay (ELISA) test.