TOXICITY OF CARBARYL TOWARD THE SOUTHERN PINE-BEETLE IN FILTER-PAPER,BARK AND CUT BOLT BIOASSAYS

Loblolly Pine bolts sprayed with 2% carbaryl (Sevimol(R) 40% A. I. Flo wable) and 1% chlorpyrifos were exposed to southern pine beetle, Dendr octonus frontalis Zimmermann. Chlorpyrifos treatment effectively preve nted attack by southern pine beetle; however, the bolts were not prote cted by 2% carbaryl. For the carbaryl-treated bolts, the number of egg niches and larval mmes were significantly reduced. However, the numbe r of adult beetles entering the host, the length of the parent galleri es, the number of pupal chambers, brood adults, and emergence holes we re not significantly (P = 0.05) different from untreated control bolts . A bark surface assay indicated that 2% carbaryl killed < 50% of the beetles at 24 h. Filter paper assay showed that the LC50 value was 0.0 7% and 0.01% at 24 and 48 h, respectively.