Development and use of degree-day models to improve management of corn flea beetles in the Stewarts disease pathosystem on corn
Esker, P.D.; Nutter, F.W.Jr
Phytopathology 92(6 Suppl): S24
2002
ISSN/ISBN: 0031-949X Accession: 034713060
The ability to accurately predict emergence of corn flea beetles (CFB) Chaetocnema pulicaria is important for timely application of insecticides to reduce the risk of Stewart's disease of corn. Using a developmental temperature threshold of 16degreeC, degree-days (DD) were used to determine the emergence of the overwintering, first, and second generations of CFB adults at six locations in Iowa. In 1999, overwintering CFB adults emerged between 38 and 64 DD, the first summer generation was observed between 290 and 360 DD, and the second summer generation emerged between 590 and 620 DD. In 2000, emergence of CFB adults occurred between 44 and 91 DD, the first summer generation was observed after approximately 320 DD, and the second summer generation occurred between 630 and 650 DD. Compared to other years, there was a three-week delay in accumulation of the first DD in 2001 and CFB was not found throughout much of the growing season. This information is being tested in field insecticide trials to determine if a DD model can be used to improve the management of Stewart's disease of corn.