A QUANTITATIVE STUDY OF FOOD CONSUMPTION AND GROWTH OF PODISUS MACULIVENTRIS (HEMIPTERA: PENTATOMIDAE)

Abstract

Nymphs and adults of Podisus maculiventris (Say), reared on four sizes (diet levels) of live larvae of Galleria mellonella (L.), captured prey, consumed food, and grew at rates varying with the size of larvae supplied. For nymphs, a direct linear relationship was obtained between rate of food consumption and daily growth and rate of food consumption and daily development. For adults, male and female, age did not affect food intake significantly, but for females alone, food intake differed significantly at different diet levels. A significant difference was also obtained for both sexes between body weight and diet level. Males and females lived longest on diet 1, apparently because of reduced metabolic activity.The number of eggs laid by each female corresponded to its food consumption for the first 35 days but decreased thereafter with age. The mean dry weights for fertile and infertile eggs at different diet levels did not differ significantly irrespective of the amount of food consumed by egg-laying females.For each nymph in each of instars 2 to 5 and for adults, the consumption quotient, an index of metabolic activity, increased as the rate of food consumption increased. For nymphs, the quotient decreased during ontogeny at each diet level, and for adults, decreased with age at diet levels 2, 3, and 4. The quotient remained constant for adults of both sexes at diet level 1.Results show that nymphs and adults of P. maculiventris can survive and mature satisfactorily for extended periods on small prey but needs larger prey to accelerate development, increase growth, and maintain a high reproductive potential.