Winter Occurance and Spring Migration of Frankliniella fusca (Hinds) (Thysanoptera: Tripidae) in North Carolina Peanut (Arachis hypogaea L.) Fields

Abstract

Abstract Overwintering of Frankliniella fusca (Hinds), tobacco thrips, in North Carolina and their subsequent spring movement into peanut fields were evaluated using two winter sampling techniques and three spring sampling techniques at the Peanut Belt Res. Sta., Lewiston, NC. In the spring of 1992 and 1993, for 14 d following peanut planting, the aerial movement of tobacco thrips was monitored using cylindrical sticky traps, trap plants, and exclusion cages. Frankliniellafusca were trapped significantly more often at 0.2 m and 0.9 m than at 1.8 m and during the afternoons. Thrips catch was significantly influenced by prevailing wind direction. No thrips were caught on sticky traps on days when maximum temperatures did not exceed 18.7 C. Frankliniella fusca began to colonize emerging peanut plants as they cracked the soil surface on days when there were temperatures above 18.7 C and times when there was no precipitation. Aerial F. fusca movement was monitored with sticky traps for three consecutive winters during 1993–96. Tobacco thrips were collected on sticky traps throughout the winter; however, counts were lower in months and years with lower temperatures. Tobacco thrips, caged throughout the winter with peanut plants infected with tomato spotted wilt virus (TSWV), were analyzed for the presence of a nonstructural protein (NSs) encoded for by the small RNA of TSWV and infectivity by ELISA. A total of eight tobacco thrips were collected, of which one tested positive.