Feeding fitness and quality of domesticated and feral predators: Effects of long-term rearing on artificial diet

Predatory geocorids, Geocoris punctipes Say (Geocoridae: Hemiptera), that h ad been reared (domesticated) for over 6 years (60 continuous generations) on an artificial diet were compared with feral (F-1) counterparts to determ ine possible domestication-associated losses in predatory capabilities. Usi ng adult female predators provided with either tobacco budworm Iarvae, Heli othis virescens F., or pea aphids, Acyrthosiphon pisum Harris, as prey, I m easured predator weights, handling time with a single prey, amount extracte d, consumption rate, and feeding (gut) capacity. Domesticated females were significantly smaller than ferals, weighing 4.53 mg versus 5.09 mg, respect ively. Domestication did not significantly influence handling times, which averaged 131 (domesticated) and 122 min (feral) for predators feeding on H. virescens larvae and 106 (domesticated) and 94 min (feral) for G. punctipe s feeding on A. pisum. Although there were significant differences in the w eights of the two kinds of prey (H. virescens larvae being about twice as h eavy as the A. pisum), both prey species exceeded the ingestion capacity of the predators. Amounts extracted by predators were 1.12 to 1.20 mg and wer e not significantly influenced by rearing background, prey biomass, or prey type. Consumption rates of 11.86 and 12.91 mu g/min were nearly identical for both domesticated and feral predators regardless of prey species.