By Katie Burch
Cotton aphid numbers have been increasing over the last couple of weeks. Aphids generally build to moderate numbers and may eventually crash due to a naturally occurring fungus. Once the aphid fungus is detected in a field, we would expect the aphid population to crash within a week or less. This fungal epizootic will typically occur in our area in early to mid-July, and has already been spotted in the Screven County area. You may notice the presence of gray, fuzzy aphid cadavers, this is indicative of the fungus.
We have very effective insecticides for controlling aphids; however, UGA research has not shown a consistent yield response when aphids are controlled. I would suggest considering plant health before you spray. If growth is being impacted across the field, insecticides may be warranted. Be sure to look for the naturally occurring fungus first, if you are considering the use of insecticides.
Source:uga.edu