Monday, December 10, 2007 - 9:53 AM

Early-season ground and aerial movement of adult pea leaf weevil, Sitona lineatus (L.) (Coleoptera: Curculionidae) as influenced by tillage system

Ryan P. Hanavan, hana7793@uidaho.edu1, Nilsa A. Bosque-Pérez, nbosque@uidaho.edu1, Sanford D. Eigenbrode, sanforde@uidaho.edu2, and D. J. Schotzko, schotzko@uidaho.edu1. (1) University of Idaho, Department of Plant, Soil and Entomological Sciences, PO Box 442339, Moscow, ID, (2) University of Idaho, Plant Soil and Entomological Sciences, Ag Sci 242, Moscow, ID

The pea leaf weevil (PLW), Sitona lineatus (L.) is an important pest of pea, Pisum sativum L., in northern Idaho. Previous research has revealed greater relative PLW abundance and crop injury in peas grown using conventional-tillage (CT) compared to no-tillage (NT) practices. Directional pitfall and aerial traps were used to assess colonization and relative activity density of adult PLW into CT and NT peas in northern Idaho during the 2005 and 2006 growing seasons. Feeding damage to the crop was also evaluated. Aerial movement was greatest in May in both years and significantly more PLW colonized CT than NT plots during this early period of crop growth. Crop feeding damage was also significantly greater in CT than in NT plots in the early season. Significantly more PLW were captured on the soil surface in CT plots than in NT plots during the period immediately following peak aerial colonization and peak plant damage in both years. Overall colonization patterns suggest that peas in CT, which emerge earlier and are greater in overall height and development during the period of peak PLW aerial colonization, attract more immigrating PLW. This leads to greater early season PLW infestation of CT plots at a critical period for pea development that ultimately influences crop yield. Later in the season, overcrowding during a critical time for PLW reproduction and oviposition may trigger PLW dispersal from CT into NT plots.

Species 1: Coleoptera Curculionidae Sitona lineatus (pea leaf weevil)
Species 2: Fabales Leguminosae Pisum sativum (pea)