Immunological detection of Helicoverpa armigera (Lepidoptera : Noctuidae) ingested by heteropteran predators: Time-related decay and effect of meal size on detection period

Indirect enzyme-linked immunosorbent assay (ELISA), dot blot, and squash bl ot were compared for sensitivity and ease of use for detecting Helicoverpa armigera (Hubner) egg antigen using an egg-specific monoclonal antibody. Th e,est results were obtained Ly dot blot, although several indirect ELISA co nditions were tried. Three of the main predator species in Mediterranean ve getable crops-Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner (Hemiptera: Miridae), and Orius majusculus (Reuter) (Hemiptera: Anthocorida e)-which had fed on H. armigera eggs, were assayed LS dot blot to detect eg g antigen in their gut. The prey was detected in all samples. Another study was conducted to determine the effect of meal size and time after feeding on the prey detection period in D. tamaninii. The proportion of prey remain ing at various time intervals after feeding was measured. Curves were fitte d to exponential and linear models and detection periods were estimated. Th e decline in prey detection over time was fitted with art exponential model for predators that ate 1 egg and a linear model for predators that ate 10 eggs. Therefore, meal size produces a considerable difference in the rate o f decline and the estimated detection periods.