The Feeding Behavior of Atlanticus testaceus (Orthoptera: Tettigoniidae)12

Abstract

The feeding behavior of Atlanticus testaceus (Scudder), a decticine katydid, was investigated in 1958–61 in Livingston County, southeastern Michigan. The ecology, local and seasonal distribution, and behavior of the insect were observed in the field; and, in the laboratory, the animal's mandibular morphology, crop contents, food selection, and food restriction were studied. Although Atlanticus prefers animal food, its diet consists more of plant than of animal materials because suitable prey are insufficiently available. Its choice of food plants is wide, including the leaves and especially the flowers of forbs, the fruits of certain woody plants and occasionally their leaves, and even the flowers of grasses. Its animal food is obtained partly by scavenging and partly by predation; the prey consists largely of small insects that are abundant in its environment, but it sometimes catches and eats larger, more powerful insects, especially when they are disabled. It is also cannibalistic. These observations, together with the strongly carnivorous adaptation of the mandibles, suggest that Atlanticus is a carnivore by preference but an omnivore by necessity.