Aphid infestations don’t usually show up in seedling rice to any great degree. Usually they start in wheat or wild hosts and move into rice. We have seen greenbug in rice in years past, but usually they are not a huge rice problem; however, one to two-leaf rice can be killed when 2-3 greenbugs feed on the plant. Larger plants can be damaged but it takes more greenbugs. Greenbugs (Fig. 1) are light green with a prominent dark green “racing stripe” down the middle of their back. You can’t miss them with a hand lens, but if you have aphids and are concerned, bring them to your local county agent for ID.
Bird cherry-oat aphids (Fig. 2) are usually green to brownish-purple and are often seen in fields, but don’t cause a problem unless they are high in numbers . The same can be said for English grain aphid (Fig. 3) and yellow sugarcane aphid. Note the cornicle (tail-pipe structures) size and color to help differentiate greenbug and English grain aphid. Note the dark coloring on posterior of the bird cherry-oat aphid.
The important part of this discussion is that you need to get out and scout your rice; small rice is vulnerable to damage. An insecticide seed treatment of Cruiser or NipSit will control aphids in rice. So, if you have either of these treatments, aphids should not be a problem. If you didn’t treat your rice with these products, look for aphids, and if you begin to see foliar symptomology such as yellowing/ reddening of leaf tissue and stunted plants with aphids present, a foliar application of an insecticide may be needed. Products labeled for control include Declare (gamma-cyhalothrin), Karate (lambda-cyhalothrin), Mustang Max (zeta-cypermethrin). Check labels for other similar products before applying. Always read and follow the label.