We continue to be in the window where we need to scout closely for aphids, spider mites and plant bugs.
Aphids are still spotty but becoming more numerous. If you run into numerous ants on the foliage, you have very likely just found aphids, as well. Treat only when high numbers of aphids are severely infesting plants, populations are building and the margins of terminal leaves are drooping.
Aphids will cause more damage when plants are suffering from lack of moisture and there are few signs of natural control agents.
No one has complained yet about spider mites. Spider mites usually appear first in border rows or sometimes in isolated spots within a field. When mites first appear, treating border rows or spot treating may prevent outbreaks.
Thresholds are not well-defined for spider mites, so we have to keep checking for mites and eggs under leaves (get a hand lens), looking for stippling on the tops of leaves and just generally scouting for spider mites, deciding to treat only when it is clearly necessary.
Remember, a hard rain usually provides good “control” of spider mites, so plan spraying around rain events to potentially save money on sprays.
I have repeatedly said that plant bugs rarely cause economic problems in South Carolina. However, we did find tarnished plant bug (TPB) at threshold (8 per 100 sweeps) yesterday in some 12-node squaring cotton where I have in a plant bug trial at Edisto REC.
AgFax Weed Solutions
Square retention is still at about 90% in that test field, so we don’t have a problem yet, but I will be treating the threshold treatment on Monday and will continue to report what we see developing with TPB. So, check for TPB in cotton.
Also, stink bugs are still numerous in corn, and I even saw one brown stink bug in squaring (12-node) cotton yesterday.
Also, corn is not as infested with corn earworm as it could be, but there are still plenty of caterpillars that are either pupating or getting ready to pupate. From there, they’ll turn into moths, emerge and look for another host, such as cotton.
So, get ready for bollworm as cotton starts to bloom. Start now. Don’t wait for blooms to appear! Go look for aphids, spider mites and plant bugs. Check square retention, as well.