Larval Feeding Site of Species of Agrilus (Coleoptera) Using a Common Host Plant

Abstract

One of the derivative principles associated with the discussion of competition and its role in producing community structure has been that of the limit to similarity of organisms of similar ecological requirements (Hutchinson 1959, MacArthur 1965). Morphological indices of phenotypic difference have been used, often without clear evidence that these differences in fact produce the assumed differences in food or other resource use. These particular examples of resource division by congeneric pairs of species of wood-boring beetles of different size are therefore of general interest to ecological theory. Species of the genus Agrilus (Coleoptera Buprestidae), characterized by rather narrow specificity of larval host, were discovered feeding on dying ornamental maples (primarily Acer saccharum Marsh. and A. platanoides L.) and honey locusts (Gleditsia triacanthos L.) in Merchantville, Camden County, New Jersey. The presence of the beetles was ascertained by cutting dead adults from twigs bored the second or third summer before. The species occurring in maples were identified as Agrilus putillus Say and the larger A. masculinus Horn; those in Gleditsia, as A. egeniformis Champlain and Knull and A. fallax Say. These plants are the recorded hosts for these species (Fischer 1928).