Identifying risk factors associated with wireworm damage in Irish potato

Irish potato is one of the most economically important specialty crops in North Carolina. The incidence of wireworm damage to Irish potato has increased significantly in recent years. Little is known about the wireworm complex in Irish potato in the state, and there is currently no way to predict the risk of wireworm damage in an individual field. The purpose of this study is to identify the economically important species of wireworm present in Irish potato and quantify risk factors associated with wireworm damage. The following potential risk factors were evaluated on commercial farms in northeastern North Carolina: crop rotation, potato variety, proximity to drainage ditches, insecticide use, and soil type . Thirty potato fields were selected based on potential risk factors; six soybean fields and 13 corn fields that will be followed in rotation by potato in 2011 were also included in the study. Wireworm baits (n=6) consisting of steam crimped oats were placed in each field beginning in May and continuing through July. Baits were collected after 14 days, transported to the lab at NC State University, and evaluated for number and species of wireworm. Fifty randomly selected tubers were collected from each potato field beginning 14 days post-tuber initiation and every 14 days thereafter until commercial harvest. Tubers were evaluated for incidence and severity of wireworm damage. Melanotus communis and Glyphonyx spp. were the most abundant species collected. Relationships between hypothesized risk factors and wireworm abundance and tuber damage will be evaluated using appropriate statistical techniques.