August Peanut Pointers
Mark Abney, Peanut Entomologist, UGA
The peanut insect management talk in August will most likely revolve around foliage feeding caterpillars.
There are soybean loopers, velvetbean caterpillars, redneck peanut worms, a variety of armyworms,
corn earworm and tobacco budworm, and a few odd ball species out in the peanut patch this week. Just
the talk of caterpillars is enough for some growers to add an insecticide to their next fungicide spray.
Scouting and treating at threshold remains the best strategy for managing caterpillars. That does not
mean that we don’t understand why some growers are quick to make a “preventive” application or to
spray when pest populations are below threshold.
As agents, you are likely to start getting calls about stories/rumors of insecticides not performing as well
as expected on caterpillars. As of this writing, I have heard of no confirmed cases of resistance. If and
when we know something definitive, I will make you aware of it; in the meantime, call me if you have
If you have reports of control failures in your county, please try to collect the following information: 1.
Active ingredient used, 2. Rate, 3. Date of application, 4. Spray volume, 5. Caterpillar species present, 6.
# and general size of the caterpillars present (samples should be taken at random from 10 locations in
the field). If you believe there was a control problem, please contact me so that we can document the
incident and try to determine the cause.
Dimilin remains a very good choice for velvetbean caterpillar, but it is not effective against loopers even
with good coverage. Loopers tend to feed low in the canopy (especially at first). It is difficult to get
insecticides down in the canopy, and many control problems with loopers and “premium products” can
be linked to application and coverage issues.
THIS IS IMPORTANT: An NGO group is currently petitioning the US EPA to revoke all food use tolerances
for the organophosphate class of chemistry. In peanut this means phorate (Thimet) and acephate
(Orthene). This is not a good situation. The comment period is currently open, and you can visit this EPA
site to review other comments (including mine) and add one of your own: Regulations.gov . If peanuts
are grown in your county you should submit a comment (this is Abney’s opinion). Losing Thimet would
be a major blow to our efforts to reduce the impact of tomato spotted wilt disease.
Please take the time to contribute to this year’s TSWV field survey. The data we get from this effort is
extremely valuable for understanding the impact of the virus on Georgia’s peanut crop and how the
Peanut Rx risk index is performing. If you did not receive instructions from Dr. Monfort and would like to
participate, let me know. It is important that we select survey fields at random and do not visit fields
with known high levels of infection.