Although not a pest of Bt cotton, budworms can sometimes be a problem of peanut and soybean. In three caterpillar samples taken from untreated peanut fields during the past week, budworms made up between 90 and 100% of the caterpillar population. Also, in conventional cotton in one of our insecticide efficacy trials, tobacco bud worms accounted for more than 95% of the caterpillars found (40 budworms, 1 corn earworm and 1 fall armyworm). This might help explain why we have experienced a few pyrethroid failures on peanut recently – that is, in most years, corn earworms typically outnumber budworms by a large margin on peanut. Pyrethroids provide poor control of budworms. Dominic Reisig has reported some initial control problems with pyrethroids on soybean this past week out east, but in this case, most of the caterpillars were earworms (podworms), suggesting pyrethroid tolerance in some populations. Because the peanut and soybean findings are recent, additional sample identification of caterpillars in these crops will help us develop a more complete picture of possible control difficulties due to resistance or budworm abundance during the coming week. We’ll be able to report the results from plenty of samples next week.
Article by Jack Bacheler