Article by Jack Bacheler
Our major point of emphasis during the next three or so weeks will the differential impact of late season pests on crops based on attractiveness and maturity. Our late corn earworm (bollworm) moth flight will be increasingly attracted to later, bigger ranker cotton fields with more immature susceptible bolls and to open-canopied, flowering soybean plants. The same trend should unfold with stink bugs and cotton, though stink bugs will tend to be more attracted to soybean fields during pod fill. In the case of kudzu bugs, the highest levels still appear to be in taller earlier planted fields while late planted beans, especially following wheat, seem to have lower levels of kudzu bugs so far.
We now have a number of cotton fields which are cutting out to the point of being unattractive and susceptible to both stink bug and bollworm injury. This is a two-edged sword, however. On the plus side, the less attractive mature fields are becoming increasing tolerant of potential caterpillar and stink bug damage. On the minus side, both bollworm moths and stink bugs readily fly to later maturing cotton fields that are still susceptible to damage. These late fields can harbor significant concentrations of pests, even when the general overall populations are low to moderate. However, we expect earworm moths and stink bug levels to be moderate to high throughout a wide range of the state during the two or three weeks or so.
In cotton fields that have been blooming for 8 weeks or more, the stink bug internal boll damage treatment threshold is at least 50%. Even though we still recommend assessing quarter-sized bolls for damage, most bolls on these plants are no longer susceptible to stink bug injury; thus the higher suggested thresholds at this time of year as the bloom period progresses.