Larval consumption and growth in host-shifted herbivorous insects: a test with the eastern tent caterpillar, Malacosoma americanum

Abstract

Laboratory experiments were conducted to analyze the ability of Malacosoma americanum, the eastern tent caterpillar, to consume, digest, convert, and grow on the leaves of non-host tree species found in close proximity to M. americanum populations in northern Michigan. Test tree species included Acer saccharum (sugar maple), Acer pensylvanicum (striped or moose maple), Fagus grandifolia (American beech), Quercus rubra (red oak),Elaeagnus angustifolia (Russian olive), and Prunus serotina (black cherry). Findings showed significant differences in relative growth rate, relative consumption rate, approximate digestibility, and efficiency of conversion of digestive matter in all test species aside from Q. rubra when compared to the specialized host P. serotina. No significant difference was found in comparing the same factors in test caterpillars fed Q. rubrawith those fed P. serotina. These results suggest possible existence of alternate available host species for M. americanum. This finding is consistent with previous observations of M. americanum feeding on oak species in nature during later instars.