Thrips Management in Arkansas Cotton

Thrips populations increase in the spring on early wild host plants and most likely on wheat. These hosts of thrips start to dry beginning in early May until midJune and thrips begin to migrate to more favorable food sources. Unfortunately, this is about the same time that cotton begins to grow. The large host acreage for thrips and their reproductive capability create a situation, in most years, where young cotton sustains some level of damage from large thrips populations. In the mid-South production area, the tobacco thrips, Frankliniella fusca, is the predominate species that occurs on cotton. Other species that have been reported in cotton include the western flower thrips, Frankliniella occidentalis; the flower thrips, Frankliniella tritici; the soybean thrips, Neohydatothrips variables, (Burris et al., 2000); and the onion thrips, Thrips tabaci (Eddy and Livingstone, 1931). Thrips injure cotton by feeding in the terminal area of the plant. This terminal feeding disrupts normal growth of the plant leaf structure. The result is usually severely deformed leaves, aborted terminals, and greatly reduced leaf area. This general injury of the plant structure greatly reduces the photosynthetic capacity of the plant. As a result, the general vigor of the plant is low, causing stunting, increased susceptibility to plant diseases, and often a delay in maturity. If not controlled, thrips injury can severely reduce stands. In addition, yields can be reduced by up to 50 or 60% in a year