Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 7, 2000
Publication Date: N/A
Interpretive Summary: Basic information on the diapause state in a North Dakota strain of the Colorado potato beetle (CPB) is presented. Methods are given to monitor diapause induction and termination. Treating diapausing CPB with a juvenile hormone analog terminates diapause and the beetles start to develop eggs. The methods presented in this paper may be useful for the storage and release of beneficial beetles used in biological control programs.
Technical Abstract: A North Dakota strain of the Colorado potato beetle (CPB) was reared under both short- (8L:16D at 20 O C ) and long-day (17L:7D at 25 O C) conditions. Age-related and pyriproxyfen- (JHA) induced changes in hemolymph proteins and free amino acids were examined. Pre-diapausing and diapausing short-day adults contained 2- to 3 times higher levels of protein than the controls with peak levels found in both sexes at 20 days. Under short-day conditions, the total free amino acid concentration in the hemolymph increased gradually up to 20 days of adult life, but long-day CPB showed marked increases during the first 10 days and then decreased afterwards. Proline, glutamine and valine were the most abundant free amino acids in both sexes of CPB held under either short- or long-day conditions. JHA treatment to diapausing adults, held under either long- or short-day conditions terminated diapause. The hemolymph showed decreases in total protein concentration, disappearance of diapause protein 1 and the appearance of vitellogenin. Furthermore, most of the JHA-treated females held under long-day conditions also matured oocytes and oviposited.