Nutritional ecology, growth and density of Acronyctodes mexicanaria(Lepidoptera: Geometridae) on a dioecious plant Buddleja cordata(Scrophulariaceae)

Abstract

Due to differential resource allocation by male and female plants, herbivores tend to feed more on male plants than on female ones. It is believed that the preferred food gives the organism a better performance. Buddleja cordatais an abundant dioicous plant in the "Pedregal de San Ángel", México City. This plant is the food of the monophagous geometrid Acronyctodes mexicanaria. The objective of this study was to determine if the dioecy of B. cordataaffects nutritional and performance parameters of A. mexicanaria(consumption, metabolic use of the food, growth, and density of caterpillars on male and female trees). Feeding preference, development time of caterpillars, and 5 variables concerning consumption and growth efficiencies were analyzed for caterpillars collected from male and female trees, and which were fed in the laboratory with leaves from trees of each sex. There was no significant difference between caterpillar density on female and male trees; however, we found that caterpillars preferred feeding on female leaves, and they obtained better nutritional efficiencies and grew more quickly when feeding on female leaves than on male leaves.