Robber flies overwinter as larvae and pupate in the soil. They overwinter and pupate in Spring. The pupae overwinter in cocoons, and the species become active from May to early August. In cooler climates, hatchlings overwinter in the nest. In warm climates, nucs can overwinter. Some species can overwinter as adults in diapause. Adult weevils overwinter in well-drained areas in or near cotton fields, and farms after diapause. However, California tiger salamander larvae may also "overwinter". Phytoplasmas can overwinter in insect vectors or perennial plants. During the fall, they leave summer habitats and migrate to neighboring uplands to overwinter. For instance, communities in warm climates may not overwinter as eggs. Barley and rye are the hardiest cereals, able to overwinter in the subarctic and Siberia. Fertilized queens then overwinter and start new colonies during the next year. Like many other "white" butterflies, they overwinter as a pupa. Surviving bollworms will overwinter in the field and re-infest the following season.