Studies of Host Plant Preference and Suitability Exhibited by Early-instar Range Caterpillar Larvae 12

Abstract

The preferences of instar II range caterpillar, Hemileuca olivae Cockerell, were tested relative to blue grama grass. Buffalograss, sorghum, foxtail millet, and sudan grass were highly preferred. Larvae fed upon, but did not prefer, Kentucky bluegrass, Russian wildrye, and side-oats grama. Non-preferred species were Japanese millet, western wheatgrass, corn, proso millet, wheat, barley, and oats. The grasses most suitable for instar I and II larval development were sorghum, sudan grass, blue grama, and com. Foxtail millet, western wheatgrass and wheat were intermediate, Japanese millet, oats, barley, Russian wildrye, and Kentucky bluegrass least suitable. In general, plants possessing the C4-dicarboxylic acid pathway of carbon fixation (C4 plants) were preferred and more suitable for larval growth than species possessing only the C3-Calvin cycle pathway (C3 plants).