Aphids – They are evident mostly in hot spots. The populations have not spread to the entire field. This is normal for this time of year. UGA Extension Entomologist, Dr. Phillip Roberts, says if anything they are late this year. They are a phloem feeding insect that does stress the plant. Sometimes sooty mold grows on the honeydew excreted by aphids which can interfere with photosynthesis. Nonetheless, the impact of our yields is variable compared to arid regions.
Beneficial’s – Scout, Andrew Taylor, has reported seeing many parasitic wasps which really help with our aphids. When we flip over leaves, you can easily see parasitized aphids – “mummies.” We also saw many lady beetles Friday. These are also helping us as predetors they feed on the aphids.
Stink Bugs – We are starting to check for stink bugs now on developing bolls. In the absence of large bolls, they will feed on small bolls. They prefer to feed on medium size bolls and both greater than 25 days old fed on rarely have yield impact.
I was looking at some fields with Andrew Friday morning, and we checked some ourselves. We walked opposite ways through the field and pulled around 20 bolls. It’s good to check the outsides, but then of course, open up the boll to see any warts or stained lint. Undamaged bolls should be clear, smooth, and white. Here is our stink bug management thresholds and cards that help us determine proper boll size. (If you need a card, let me know.)