Thrips have many hosts, including grasses, grains and alfalfa. Large populations often develop on these hosts and fly into cotton fields when the cotton seedlings are developing. Thrips feeding causes severe deformation and stunting of the developing cotton leaves. The Upper Southeast cotton region (Virginia and North Carolina) could be designated “Thrips Central” for the Cotton Belt. Jack Bacheler, a North Carolina Extension Entomologist, explains…
“With the exceptionally warm winter and good moisture levels, at this point it looks like thrips flights into cotton should be both large and early this year. … Our region has earned the distinction of having the highest levels of thrips and greatest potential damage to seedling cotton of anywhere in the U.S. In some tests, with the help of a microscope, we sometimes count as many as 200 to 500 thrips per 5 seedlings! That’s a “ton” of thrips, especially if seedlings are unprotected. So it’s probably not a surprise that Virginia and North Carolina have the highest ratio of surrounding host vegetation to small average cotton field size.”
“Over the past eight years, more than 85 percent of our cotton acreage has been over-sprayed [i.e. sprayed over] following a seed treatment. With the potential for thrips damage lasting up to 5 or 6 weeks after planting and seed treatments varying from about 2 to 3 weeks in their activity, a high percentage of foliar follow-up treatments for thrips is not surprising.”
Author: Jack Bacheler
Affiliation: North Carolina Extension Entomologist
Title: Heavy thrips populations anticipated.
Publication: Southeast Farm Press, April 18, 2012. Available: http://connection.ebscohost.com/c/articles/76291692/thrips-pressure-heavy-mississippi-cotton