The status of the insect pests of cotton in Virginia

Most cotton in Virginia planted before mid May has blooms at the tops of plants, has mature bolls and is safe from further damage by stink bugs or bollworms. Local estimates are that this describes about 75% of the acreage. The remaining 25% planted after May 15 has not cut out yet and still has some insect-susceptible bolls, but percentage of susceptible bolls on a plant goes down each day as more bolls mature. Most fields, whether BG2 or WideStrike, have been treated one time for bollworms/stink bugs. In most years, this single treatment is sufficient for protection until harvest. But each year is different. This year summer rainfall patterns and some relatively cooler temperatures in recent days have slowed maturity a bit, especially the later planted fields. Whereas in most years by this time we can find some open bottom bolls, few are visible this week. So, early planted cotton is safe, but late planted cotton needs to be scouted for another few weeks, and may require a second treatment.

What about top-crop growth? We are not expecting a lot of new top-crop growth but it can happen. Late season top-crop growth is most common in summers when cotton is heat/drought stressed during the summer and cuts out early, then begins regrowth as a response to late August early September rain. This was the case in a lot of fields last year. This top-crop presents a new set of insect susceptible bolls that is very attractive to the final season’s generation or worms and stink bugs. But in most cases, the top-crop does not have enough lint potential to warrant another insecticide treatment.

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