Parasitoids and Predators of Insect Pests on Chrysanthemums in Hawaii

Abstract

Trials were conducted at a commercial cut-chrysanthemum nursery in Mountain View, Hawaii to evaluate biological control of chrysanthemum insect pests. No chemical pesticides were applied throughout the growing season. Numerous parasitoids and predators of the agromyzid leafminer, Liriomyza trifolii (Burgess), the green peach aphid (GPA), Myzus persicae (Sulzer), and the variegated cutworm (VC), Peridroma saucia (Hubner), were recovered. The two dominant parasitoid species of L. trifolii, Diglyphus intermedius (Girault), and Ganaspidium utilis Beardsley, provided biological control during the first 7 to 9 weeks after planting when the unmarketed portion of the chrysanthemum foliage was growing. Additional biorational or chemical control methods are necessary for GPA. VC, and L. trifolii when their damage affects the marketable portion of the crop.