Plum Curculio Migration Nearing Its End: Regional PC Model Update

It was a slow start for the plum curculio (PC) this season with few egg laying scars 7 days out from petal fall. However, egg laying by the beetle began in earnest shortly after 1st cover in the mid-Hudson Valley. During the thinning period low rates of carbaryl may have bought some time between applications, helping to reduce fruit injury between insecticide applications targeting the PC.

We presently have 285 accumulated degree days (base 50°F) from petal fall (May 19th) through May 8th in Highland, NY. Effective insecticide residual should be maintained until 308 degree days have accumulated from your petal fall date of McIntosh. Using predicted temperatures over the next day, we expect to accumulate 19DD, bringing the forecast date for the 308DD completion of PC migration to June 10th.

If you recovered on May 24th or earlier you would be out >14 days with 0.76″ of rainfall on the application in the Mid-Hudson Valley. You should consider an insecticide application to pick up the last of the PC along with Codling Moth. Applications of efficacious insecticides (such as high rates of Calypso or Imidan…) out 10 days or less by the 10th of June would have enough residue to kill the last of the PC migrating into orchards over the next two to three days.

The neonicotinoid Calypso 4F® (thiacloprid), the OP Imidan 70WP®, WSP® (Phosmet), carbamate; Sevin® (carbaryl), and pyrethroids Danitol 2.4EC® (fenpropathrin), Asana XL® (esfenvalerate), Baythroid XL 1E®, 2EC® (beta-cyfluthrin), Lambda-Cy 1CS® (lambda-cyhalothrin), Warrior 1CS® (lambda-cyhalothrin), Proaxis 0.5CS®, and pre-mix formulations Endigo ZC® (lambda-cyhalothrin / thiamethoxam), Leverage 360® (imidacloprid / beta-cyfluthrin), Gladiator® (zeta-cypermethrin / avermectin), Voliam Express® (lambda-cyhalothrin / thiamethoxam), Voliam Flexi® (chlorantraniliprol / thiamethoxam), should provide excellent control of both insects.