To Spray or Not to Spray Late Season Insects – AgFax
We are almost at the end of the season. Pawnee will likely be ready to shake by mid to late next week and we are nearing the end of grain fill on most other cultivars. I’ve had many calls today about whether or not to spray a pyrethroid for stink bugs and/or weevils and whether or not to worry about aphids/mites burning behind those sprays.
I also received several calls today about black pecan aphids appearing and needing to be treated at this stage. Since we are so close to harvest, you need to pay close attention to the pre-harvest intervals of insecticides.
Last month’s rain kept aphid and mite pressure relatively low. Now that we have clear weather forecast for the next 10 days, it’s possible these pests will reappear, but so close to the end of the season, is it worth spraying?
First of all, it’s too late to worry about these pests on Pawnee, so just be prepared to harvest this cultivar and don’t worry about the bugs.
On later cultivars that haven’t opened yet, if you’ve ever had weevil or stink bug problems, you should probably still spray them at this point. Most weevil/bug materials have a 14-21 day interval to harvest. You can add an aphid and mite material to prevent flare-ups, but also keep in mind the pre-harvest intervals of these materials.
Most aphicides have a DAR of 7-14 days. The exception to this is Carbine, which has a PHI of 40 days. So if you apply an aphicide, it’s too late to use Carbine. When it comes to acaricides, Abamectin has a PHI of 21 days. Nexter has a PHI of 7 days and will work on both aphids and mites. You can check out the Georgia Pecan Spray Guide for more details on other products.
I will continue to watch for the black aphid this week and if any nymphs are seen it may be a good idea to spray. After this week, I wouldn’t care too much about them. We come in late in the season and the aphid/mite populations usually don’t build up as much in late September/October as they do in August.