Relationship between injury and damage to potatoes by wireworms

A relationship between injury (any penetration of a tuber) and damage (in accordance with the U.S. Standards for Grades of Potatoes) caused by the sugarbeet wireworm,Limonius californicus (Mannerheim), the Pacific Coast wireworm,L. canus LeConte, and the Great Basin wireworm,Ctenicera priunina (Horn), to potatoes was determined. Based on tuber weights, the percentage of damage (D) increased curvilinearly with increased percentage of injury (I). Percentages of injured and damaged tubers based on tuber weights were significantly different from those based on tuber count. Difference in the relationship of injury vs. damage between untreated and fonofos-treated tubers was not significant. The regression D = -0.012 + 0.1 111 + 0.003I² can be used to estimate the amount of damage from the amount of injury without the necessity of cutting and measuring feeding holes.