A procedure for pinpointing cannibalism, intraguild predation, and life stage-specific feeding events

A predator gut analysis technique is described that can simultaneously pinpoint predation events which are life stage-specific, intraspecies-specific (cannibalism) and interspecies-specific (intraguild). The third and fifth larval life stages of green lacewing, Chrysoperla carnea Stephens s.l. (Neuroptera: Chrysopidae), were marked with rabbit IgG and chicken IgY, respectively. The uniquely marked lacewing life stages were then introduced into caged arenas (n = 59 caged experimental units) containing a cotton plant and an assemblage of generalist predators. The predators released into each arena were recaptured after 6 h and their gut contents were examined for the presence of rabbit IgG- and chicken IgY-marked lacewing remnants by an anti-rabbit and anti-chicken enzyme-linked immunosorbent assay (ELISA), respectively. The predator gut ELISAs detected one cannibalism event and 14 and 8 intraguild predation (IGP) events on third and fifth instar lacewings, respectively. This proof-of-concept study shows that this universal prey immunomarking technique (UFIT), when combined with field cage methods, can be useful for pinpointing cannibalism and life stage-specific predation events.