Larval substrates of herminiine noctuids (Lepidoptera): Macrodecomposers of temperate leaf litter

Abstract

More than 40 species of herminiine noctuids occur in eastern forests. Nearly all of these are detritivores, skeletonizing fallen leaves and thereby accelerating nutrient cycling in forest ecosystems. Larval feeding assays were conducted for 8 herminiine genera with air-dried leaves from 10 tree and shrub genera. Survivorship was high on dead foliage of Carya ovata (Juglandaceae), Larix decidua (Pinaceae), Prunus serotina (Rosaceae), Quercus alba and Q. rubra (Fagaceae), Vaccinium corymbosum (Ericaceae), and Vitis sp. (Vitaceae); intermediate on Acer, rubrum (Aceraceae) and Rhus glabra (Anacardiaceae); and low on Liriodendron tulipiferum and Pinus strobus (Pinaceae). Additional larval feeding assays were performed using Quercus alba leaves treated with an antibiotic, fungicide, and a combination of the two. Treatment with the cell-culture grade antibiotic had no effect on survival of Chytolita morbidalis (Guenee) larvae. In fact, mean pupal weights were significantly greater for larvae fed treated leaves. Treatment with the general purpose fungicide Daconil lowered the survival of C. morbidalis. Given that several species were able to complete their development on air-dried foliage, we suspect that many herminiines are not dependent on the epiphytic bacteria and fungi on leaf litter, as has been suggested by other studies.