Practicies that better target pesticide applications to when crops risk economic damage reduce the amount and frequecy of pesticide applications. Economic population thresholds have been established for many insects in tomatoes, but professional crop advisors (PCAs) usually cannot afford the time for frequent and intensive sampling. Pheromone traps can be useful for determining if adult insects are present, but are less successful for determining economic threshods. Using bucket traps to determine a biofix, coupled with degree-day models to predict generations, can help create a window for critical montitoring in the field. During the past 30 years, the parameters of physiological models have been determined for many pests common to vegetable crops and summarized in the University of California Integrated Pest Management (IMPACT) computer web site. However, the methodology for practical field use needed to be developed and validated. Five species monitored include Spodoptera exigua, Trichoplusia ni, Helicoverpa zea, Agrotis ipsilon and Peridoma saucia. Calendar dates of biofixes and generation cycles were estimated using the pheonology models from regional traps monitored year round. The biofixes and generation cycles of the insect phenology models were compared to trap data using regression analysis in six California counties. Trap catch data from 1998-1999 demonstrate that published phenology models can be a useful pest management tool based on regional trapping locations.
Species 1: Lepidoptera Noctuidae Spodotera exigua (beet armyworm)
Species 2: Lepidoptera Noctuidae Trichoplusia ni (cabbage looper)
Species 3: Lepidoptera Noctuidae Helicoverpa zea (tomatoe fruitworm, bollworm)
Keywords: Insect Phenology Models, Insect pests of vegetable crops
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA