Drs. Monfort, Srinivasan, and I spent several days last week walking peanut fields to get a measure of how severe tomato spotted wilt is in this year’s crop. Incidence of virus symptoms varied from 0 to over 30% in the fields that were surveyed.
This effort also gave me an opportunity to see first hand what else was happening in terms of insect and mite activity over a large area of South Georgia. As a general rule, insect pressure was low, but there were a few fields with real or developing problems.
Several non-irrigated fields had lesser cornstalk borer infestations, and a couple fields had two spotted spider mites. Redneck peanutworm was the most common foliage feeder I saw. This insect has been very abundant in my test plots this year.
I thought the redneck peanutworms had run their course a week or so ago, but we seem to have another generation showing up on the research farms around Tifton. There are no thresholds for this insect, and I doubt that it will cause measurable yield loss in most situations. It does however, make the foliage look ragged.
Some fields had relatively high numbers of southern corn rootworm (cucumber beetle) adults, and I received a couple more reports of pod damage this week. As I mentioned in a post last week, there is little that can be done to manage rootworm infestations in peanut once the larvae are feeding on pods.
I have not seen much in the way of caterpillar pressure, but I have gotten calls that indicate some fields are experiencing moderate to heavy infestations. There are velvetbean caterpillars, soybean loopers, and armyworms in spots. Most of the moths I saw in fields last week were tobacco budworm. I will be watching my plots closely for caterpillars in the coming weeks.
Whiteflies are not typically a pest of peanut, but we are seeing some whitefly activity in peanut fields in Tift and surrounding counties. So far, there have been no reports of reproduction occurring in peanut, and we should all hope that does not change. There are few options available for whitefly management in peanut, and most fields still have a long way to go before harvest. If anyone observes whitefly nymphs on peanut, please let me know.
Herbicide Resistance Info
Folks are seeing garden fleahopper in peanut again this year. The impact of this insect on peanut is unknown, but some fields were treated in 2015 due to very high populations and subsequent defoliation. We do not have a good option for controlling garden fleahopper; pyrethroids have generally provided only partial control.
Growers should be aware that there is a “little bit of everything” in terms of insect and mite pressure in Georgia peanut fields right now, but that does not mean every field is infested or will need to be treated.
For more information about these and other insect pests of peanut, please contact your local UGA County Extension Agent.