These adults eat little if anything and cause no economic damage. As soon as the female emerges from the soil. The sugarbeet wireworm prefers vegetated areas for laying eggs while the Pacific Coast wireworm prefers unvegetated spots. Some females may not lay all of their eggs in one location but will return to the soil surface, fly to a nearby area, then reenter the soil and continue egg laying until they have deposited approximately 300 eggs. Because of these flights and the specific food and moisture requirements of larval development, spotty patterns of wireworm infestations are often found.
Wireworm larvae cause the greatest feeding damage during their second and third years.
In the spring when soils are moist and temperatures reach 50 Fahrenheit or above, the larvae move upward toward the soil surface from depths of 6 to 24 inches where they have spent the winter. When soil surface temperatures reach 80 Fahrenheit or higher, they move downward again. In irrigated fields with complete foliage cover, this higher temperature level may not be reached. During the third or fourth seasons in late summer, mature larvae transform to fragile pupae in earthen cells. In 3 to 4 weeks, the pupae change to adults and stay in the soil until the following spring.