INTEGRATED MANAGEMENT OF INSECT PESTS IN STORED GRAIN AND IN PROCESSED GRAIN PRODUCTS
Location: Stored Product Insect Research Unit
Title: HYDROPRENE PROLONGS DEVELOPMENT TIME AND INCREASES MORTALITY IN WANDERING-PHASE INDIANMEAL MOTH (LEPIDOPTERA: PYRALIDAE) LARVAE
Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 5, 2005
Publication Date: August 1, 2006
Citation: Mohandass, S., Arthur, F.H., Zhu, K.Y., Throne, J.E. 2006. Hydroprene prolongs development time and increases mortality in wandering-phase Indianmeal moth (Lepidoptera: Pyralidae) larvae. Journal of Stored Products Research 99:1509-1519.
Interpretive Summary: The insect growth regulator hydroprene (Gentrol) is labeled for control of stored-product insects in food storage areas. However, there is no published information as to whether this insecticide would prevent mature Indianmeal moth larvae from reaching the adult stage. We exposed wandering-phase larvae for various time intervals, at different temperatures, on concrete treated with the label rate of hydroprene. Adult emergence was delayed on short exposure intervals and ceased as the exposure interval increased. As temperature increased, adult emergence was further delayed or reduced. These results indicate that exposure to hydroprene could reduce overall populations of the Indianmeal moth in indoor facilities.
Wandering-phase Indianmeal moth larvae, Plodia interpunctella (Hübner), were exposed to the label rate of hydroprene (1.9 X 10-3 mg[AI]/ cm2) sprayed on concreted petri dishes. Larvae were exposed for 1, 3, 6, 12, 18, 24, and 30 h and maintained at 16, 20, 24, 28, and 32ºC and 57% relative humidity until adult emergence. Larval development time and mortality were significantly influenced by temperature and exposure intervals. Maximum development time (47.2 ± 1.3 d) occurred at 16ºC, and the minimum development time (7.0 ± 0.5) occurred at 32ºC. Larval mortality generally increased at all of the five tested temperatures as exposure period increased. The greatest mortality (82.0 ± 0.1%) occurred when larvae were exposed for 30 h at 28ºC, and minimum mortality (0.0 ± 0.5%) occurred at 16ºC when larvae were exposed for 1 h. The relationships between temperature, exposure period, and development time were described by polynomial models, based on lack-of-fit tests. Hydroprene has potential to be an effective alternative to conventional insecticides in surface treatments for Indianmeal moth management. Response-surface models derived from this study can be used in simulation models to estimate the potential consequences of hydroprene on Indianmeal moth population dynamics.