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Hi. This is Jack Bacheler, NCSU Extension Entomologist with the Wednesday Cotton Insect Update. It’s Wednesday, July 8.

As often happens during summers that seem to be pointed strongly toward the dry side in early July, we have both a high proportion of cotton producers who are in brink of desperately needing rain and some who are in a different world. Such is the case now, with producers in most of the western and central part of the state very dry with the exception of a few with small to locally good rainfalls. At the same time, some areas east of Williamston are in the 2 to 5 inch range. It was odd to be at the Vernon James Center in Plymouth yesterday a few days after their 5-inch rain with all of the fields saturated and muddy water filling the ditches. However, in general, most of the state could benefit from substantial rainfall, and soon. Corn in many areas of the state has already taken a substantial hit and the finding of soybean damage by drought-loving lesser corn stalk borers this early in Wayne County south of Grantham isn’t a good sign.

Spider mites could be an underappreciated threat in the coming days and weeks if the weather patterns remain dry. A few fields in Sampson County this Monday had very high mite levels, with mites on essentially every plant and damage to the point of bottom leaf defoliation – definitely a treatable situation. Other calls this past week have referred to light but widespread populations. When a foliar spray is indicated, high pressure and volume is needed, and a post-treatment check by day 5 is advised for the possibility of a second spray.

In the plant bug arena, some square retention counts of less that 80% are being reported. I stopped in a handful of cotton fields in Washington and Martin counties yesterday and most fields had upper square retentions in the 75 to 85% range, although sweeping in this case revealed low levels of plant bugs. As blooming begins, continue upper square retention counts, looking for the blackened small squares associated with plant bug damage, and checking for dirty blooms. In our experience, if dirty bloom counts are less than 10%, economically damaging levels of plant bug are unlikely at that time. Dirty bloom counts of over 15 or 20% should be followed up with more intensive sampling for live plant bugs, preferably with a sweep net for pre-blooming cotton and a drop cloth for after bloom initiation. We do not tend to get the high levels of quickly invading plant bugs common to the mid-south which can render dirty bloom counts on the late side in those situations.

Although some cotton aphid infestations are sure to develop during the last three weeks in July, no economic infestations have been reported to date.

We are approximately two weeks away from reporting on the status of stink bugs and the arrival of the major bollworm moth flight.

We’ll provide the next cotton insect update on a hopefully wetter July 15, 2009.