Searching behavior of Coleomegilla maculata larvae feeding on colorado potato beetle eggs

Coleomegilla maculata DeGeer (Coleoptera:Coccinellidae) fourth instars were placed singly into a searching arena containing either 1 or 4 potato (Solanum tuberosum L.) plants, with a total leaf area (both sides) of approximately 0.20 m² per plant. Prey were approximately 24-h-old eggs of Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). Three egg densities were used: 2 egg masses per 4 plants (i.e., 2.5 egg masses/m² of leaf area), 2 egg masses per I plant (i.e., 10 egg masses/m²), and 7 egg masses per 1 plant (i.e., 35 egg masses/m²). Predators were observed for 4 h. Time spent in selected behaviors (searching, feeding, resting) and location in the plant canopy during each behavior were recorded. Predators exhibited both extrinsic and area-restricted search behaviors. Predatots searched a greater amount of leaf area and for longer time periods at 2.5 egg masses/m² compared to 10 or 35 egg masses/m². Successful predators consumed approximately 8 eggs during the 4-h period and the handling time was approximately 8 min per egg. C. maculata fourth instars consumed entire eggs when they initiated feeding; subsequent eggs were partially consumed. At 10 and 35 egg masses/m², predators successfully finding eggs spent more time resting than did predators at 2.5 egg masses/m².