Survival of the monarch, Danaus plexippus (L.), in agricultural systems has been a recent issue of concern due to the potential toxic effects of Bacillus thuringiensis (Berliner) corn pollen on D. plexippus larvae. The exotic coccinellid, Harmonia axyridis Pallas, is another potential biological stressor of D. plexippus in agricultural systems. Harmonia axyridis is rapidly becoming a dominant predator in some corn and soybean systems in the Midwestern USA. Our preliminary studies have shown that late instar larvae of H. axyridis can consume more than 15 D. plexippus eggs in 24 h, whereas adults consumed an average of only 1.5 D. plexippus eggs in 24 h. As an initial step towards evaluating the potential risk of H. axyridis on D. plexippus, functional response studies of H. axyridis predation on D. plexippus were conducted under laboratory conditions. Data will be presented for various stages of predator and prey. Application of these results and new phenology data for D. plexippus and H. axyridis in the field will be discussed within the context of a complete risk assessment for D. plexippus.
Species 1: Coleoptera Coccinellidae Harmonia axyridis (multicolored Asian lady beetle)
Species 2: Lepidoptera Danaidae Danaus plexippus (monarch butterfly)
Keywords: functional response
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA