For several weeks, they alternately feed and lay eggs. Occasionally, a few adults can be found in houses during winter, apparently able to overwinter in this stage. Most die in the fall, and larvae survive the winter in the soil. There is only one generation per year. It is critical to apply an insecticide after most adults have emerged, but before they begin laying eggs.
Control is aimed at adults as they crawl on the ground and up the plants.
The second or third week of June is optimal. There is NO evidence that grub treatments will control the species. Treat the soil surface and the main stems and branches thoroughly to destroy the feeding adults. Examine Yew by looking for adults feeding down in the center of plants, near the main trunk or stems. Adults usually hide in crotches under heavy bunches of needles.