COMPARISON OF 2 STEINERNEMATID SPECIES FOR CONTROL OF THE ROOT WEEVILDIAPREPES-ABBREVIATUS

Steinernema carpocapsae Weiser All strain was compared to Steinernema riobravis Cabanillas, Poinar, and Raulston for control of the root wee vil, Diaprepes abbreviatus (L.), in the laboratory and in potted citru s. In the laboratory bioassay, D. abbreviatus larvae were exposed to 3 0, 60, and 120 nematodes/cm3 in sand. Insect mortality 1 week after ap plication was greater (P less-than-or-equal-to 0.05) for S. riobravis than for S. carpocapsae in the laboratory bioassay. In the greenhouse bioassay, D. abbreviatus larvae were exposed to 3 and 9 nematodes per cm3 of soil in potted citrus. Again, at each rate, mortality was great er (P less-than-or-equal-to 0.05) in pots treated with S. riobravis th an in pots treated with S. carpocapsae. The results of this study sugg est that S. riobravis is a better biological control agent against D. abbreviatus larvae in potted plants than S. carpocapsae.