Distribution of frass produced by larval lepidoptera in a hardwood canopy /

Abstract

I studied the distribution of frass produced by larval Lepidoptera in a latesuccessional, 10-ha forest plot at the Ravenna Army Ammunition Plant in Portage County, Ohio. From July through September, 1998, fallen frass pellets were collected from the dominant tree species, American beech (Fagus grandifolia) and sugar maple (Acer saccharum), using 1m2 frass nets. Two frass nets were placed beneath each selected tree in three areas of the plot: along a road edge, in the interior ofa forest, and along the South Fork ofEagle Creek. Frass pellets were collected on a weekly basis from a total of 120 nets and were weighed to the nearest O.Olg. Frass weights for beech and maple did not differ between the three transects. However, frass weights were significantly greater from beech than from maple trees (Mann-Whitney test, P= 0.01). Frass pellets from the peak collection were also separated into size classes. Based on weights, the size of frass did not significantly differ between beech and maple. Live specimens were collected from June through July, 1999 and their frass pellets were used to develop a key for the identification of 14 late-season lepidopteran species found in a beech-maple canopy. Two species of geometrid larvae, Plagodis fervidaria and H}pagyrtis unipunctata, were distributed differently depending on their host. When feeding on beech, both species were more abundant on trees located along the creek edge but when feeding on maple, they were more abundant on trees growing along the road edge (Kruskall-Wallis, P = 0.001).