When the calendar turns to August, I immediately think about controlling pecan weevils. If the soil contains enough moisture, male weevils will start emerging in late July. By early August, females will appear. Both sexes migrate to pecan nut clusters in the hopes of finding a suitable mate (photo above).
During this courtship phase, male and female weevils will feed on nuts causing nuts, that are still in the water stage, to drop from the tree. Female weevils will continue to probe nuts until the pecan kernel inside the nut starts to firm up. Once a female finds solid kernel they will lay 5-7 eggs inside the nut. Our job, as pecan growers, is to prevent females weevils from laying eggs.
Today, I walked over to a Kanza tree to check on nut development. With recent rainfall, the nuts are growing rapidly (photo at left). This is the time of year when nut clusters are clearly in the tree's canopy and I start looking forward to a successful harvest season.
In my orchard, the weevil population is very low so I'm not overly anxious to start spraying for weevil. However, I am planning to spray for stinkbugs next week and that spray should take care of any early emerging weevil adults. My biggest concern is that fact the my neighbors native pecan grove doesn't appear to have a crop this year. That means, any weevils that emerge across the fence will probably migrate over to my orchard.
From past experience, migrating weevils are not captured in trunk mounted traps. So this year, I'll be making a weevil spray as soon as my Kanza nuts enter the dough stage in an effort to stop migrating weevils from becoming established in my orchard.
If you want to monitor pecan weevil emergence in your grove, I'd suggest that you build some Circle pecan weevil traps. Step by step instructions for building traps can be found HERE.