Geographical Distribution and Host Crops of Bemisia tabaci (Gennadius) (Hemiptera

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most economically important pests of agricultural crops worldwide. We determined the biotypes of B. tabaci collected from vegetables throughout the Ryukyu Islands (95 greenhouses and 55 open fields) from 2005 to 2009. B, Nauru and Q biotypes were found, among which Q was first confirmed to inhabit Ryukyu Islands in 2009. B biotype was identified in all greenhouses and 34 open fields. Q biotype was identified in only two bell pepper greenhouses and was not found in open fields. Nauru biotype was identified in two greenhouses and 28 open fields. B biotype was dominant in greenhouses, but the abundance of Nauru biotype in open fields was not very low compared to that of B biotype. Larvae of B biotype were found on all crops investigated except potato (12 families, 27 species), whereas the host range of the Nauru biotype was narrower (4 families, 6 species), with its occurrence strongly biased toward sweet potato. It is possible that the difference in biotype composition among the cultivation environments and host crops reflects the difference in ecological characteristics such as host preference and susceptibility to insecticides among the biotypes.