Development time and consumption rate of Podisus maculiventris feeding on Microtheca ochroloma

The yellowmargined leaf beetle, Microtheca ochroloma Stål (Coleoptera: Chrysomelidae), native of South America, is a pest in cruciferous crops since its introduction into the United States in 1945. The adults and larvae of this beetle make holes in the leaves, thus lowering the quality of the vegetables. Since there are no known parasitoids or pathogens in the United States, insecticide treatment is the most common tactic to control crop damage. However, this is not an option for organic growers in the southern states. Experiments were conducted to study the development time and consumption rate of the spined soldier bug, Podisus maculiventris (Say) (Hemiptera: Pentatomidae), as a biological control agent of the yellowmargined leaf beetle. Ten nymphs were individually provided eggs and 15 nymphs were individually provided 3rd and 4th instars of the yellowmargined leaf beetle in plastic cages (8 cm³) at 25^oC, 75% RH and 12:12 photoperiod. Mean nymphal development time was 20.1±0.1 and 17.7±0.1 days when the predator was fed prey eggs or larvae, respectively. Mean number of prey eggs and larvae consumed by P. maculiventris nymphs during development was 753.9±6.4 and 67.0±0.9, respectively. Mean daily consumption rates of prey eggs were 24.2±2.1 by 2nd instars, 68.3±3.6 by 3rd instars, 200.7±12.6 by 4th instars, and 461.0±13.9 by 5th instars. Mean daily consumption rates of prey larvae were 6.3±0.6 by 2nd instars, 10.8±0.8 by 3rd instars, 19.4±1.2 by 4th instars, and 30.5±2.0 by 5th instars. Mean adult weight was 52.32±1.16 mg for P. maculiventris nymphs feeding on M. ochroloma eggs and was 65.52±0.94 mg for nymphs feeding on larvae.