Increased Green Onion Yields Associated with Abamectin Treatments for Liriomyza sativae (Diptera: Agromyzidae) and Thrips tabaci (Thysanoptera: Thripidae)

Liriomyza sativae is a major pest of green onions (Allium cepa L. van "aggregalum") in the Waianae region of O'ahu, Hawai'i.Field trials were conducted for 2 seasons to evaluate abamectin for L sativae control.Weekly applications of 0.02 kg abamedin/ha beginning 2 weeks after transplanting and continuing up to 7 d before har vest resulted in significant increases in marketable yield.In the first season, although counts of live leafminer larvae did not decrease in abanxclin-lreatcd onions, green onion yield increased 71%.In the second season, leafminer pupae were counted instead of leafminer larvae.Counts of leafminer pupae decreased in abamectin-treated onions and green onion yield increased by 40%.Abamectin was effective in controlling L sativae in green onions with possibly little or no effect on parasitoids.Onion thrips (Thrips tabaci) injury in abamectin-treated plots was significantly lower than in untreated control plots.1984, Mason et al. 1987).Abamectin (AVID 0.15 EC [2% emulsifiable concentrate], AGRI-MEK 0.15 EC; Merck & Co., Inc., Rahway, NJ) has been evaluated for leafminer control in several crops.In cantaloupe, abamectin reduced the number of Liriomyza Icafmines per leaf (Royer &