VERNAL INFUSION OF THRIPS INTO NORTH-CAROLINA PEANUT FIELDS

Thrips (Frankliniella spp.) emergence from soil was monitored in newly seeded peanuts in 1990 and 1991 and in newly seeded com planted in rotation with peanuts in 1991, using emergence and exclusion cages. Sticky cards were used in 1990 and 1991 to monitor thrips activity outside of emergence/exclusion cages. Thrips collected in 1991 from emergence cages, from peanut and com foliage inside and outside of emergence and exclusion cages, and from sticky cards were identified to species. Two and nine thrips individuals were found in emergence cages in peanut fields in 1990 and 1991, respectively. Four thrips were found in emergence cages in com in 1991. In both years, thrips abundance and damage on peanut or com plants inside emergence and exclusion cages was low compared with plants outside cages. All thrips collected from cages and plants were Frankliniella fusca (Hinds), which is a vector of tomato spotted wilt vims (TSWV). Based on sticky card counts, thrips were abundant in fields in which cages were placed. In 1991, nearly 20% of the 9,102 thrips collected from sticky cards were TSWV vectors (17.3% F. fusca, 0.2% F. occidentalis, and 0.9% Thrips tabaci). These data indicate that in-field emergence was not an important source of thrips attacking newly planted peanut and com in these fields.