Assessing Biochemical Fitness of Predator Podisus maculiventris (Heteroptera: Pentatomidae) in Relation to Food Quality: Effects of Five Species of Prey

Preferences of female predators for various species of prey may not correlate with nutritional value of the prey, notably with regard to resulting rates of reproduction in the female predator. This study assessed the biochemical status of adult female Podisus maculiventris (Say) as affected by prey species. Colony-reared females were fed one of Þve species of natural or factitious prey: beet armyworm, Spodoptera exigua (Hübner); fall armyworm, Spodoptera frugiperda (J.E. Smith); cabbage looper, Trichoplusia ni (Hübner); wax moth, Galleria mellonella (L.); or yellow mealworm, Tenebrio molitor (L.). Fresh weights and contents of lipid, protein, and yolk protein were compared over periods of 7, 15, and 22 d. Fresh weights and protein showed no signiÞcant differences by trial length or by prey species. Total lipid content was the most signiÞcant parameter in relation to time and species of prey, ranging from 5.3 to 15.5% of mean fresh weight. Female P. maculiventris varied signiÞcantly in total lipid content by prey species at 15 and 22 d, and by week only when fed fall armyworm.Highest lipid contentswereobserved in females fedyellowmealworm, and lowest lipid contents were observed in females fed cabbage looper and beet armyworm. Yolk protein content did not correlate with cumulative oviposition, but it did vary with time in those females fed on the beet armyworm or the wax moth. Lipid content in female predators may vary inversely with reproductive potential or egg load and offers a quantitative measure of food quality.