Podisus maculiventris Say pest age-specific predator preference

Spined soldier bug, Podisus maculiventris Say (Hemiptera: Pentatomidae), is a generalist predator, feeding on more than 90 insect species. In soybean, this predator is often found with the pest Pentatomidae, however, little is known if P. maculiventris prefers specific instars of different stink bug pest species. A no-choice study was initiated to begin to understand the feeding of P. maculiventris on different nymphal instars of three pest stink bug species: southern green stink bug, Nezara viridula L., Euschistus quadrator Rolston, and redbanded stink bug Piezodorus guildinii (Westwood). Adults (3-5 days old) P. maculiventris were starved for 24 hours prior to use in experiments. Each adult was placed in an arena and then given 8, 6, 4, or 2-second, third, fourth, or fifth instar nymphs, respectively, of each pest stink bug species. A complete randomized design was used for this study, with 10 replicates for each experiment, repeated 3 times. After 24 hours, the number of nymphs consumed was counted and weighed. Results indicate P. maculiventris consumed nymphs of all three stink bug species. Podisus maculiventris mean daily per capita consumption (mg/predator/day±SE) was 2.7±0.7, 9.0±2.0, 16.9±2.5, and 8.1±1.9 second, third, fourth, and fifth instar E. quadrator respectively, 2.6±0.4, 2.3±0.8, 9.2±1.4, and 8.6±2.3 second, third, fourth, and fifth instar P. guildinii respectively, and 6.5±1.1, 23.5±7.8, 14.7±3.6, and 42.6±6.1 second, third, fourth, and fifth instar N. viridula respectively. Therefore, the mean daily per capita consumption was greater for the second, third, and fifth instar N. viridula than for E. quadrator and P. guildinii.