Toxicity of carbaryl toward the southern pine beetle in filter paper, bark and cut boltbioassays

Loblolly Pine bolts sprayed with 2% carbaryl (Sevimol(R) 40% A. I. Flowable) and 1% chlorpyrifos were exposed to southern pine beetle, Dendroctonus frontalis Zimmermann. Chlorpyrifos treatment effectively prevented attack by southern pine beetle; however, the bolts were not protected by 2% carbaryl. For the carbaryl-treated bolts, the number of egg niches and larval mmes were significantly reduced. However, the number of adult beetles entering the host, the length of the parent galleries, the number of pupal chambers, brood adults, and emergence holes were not significantly (P = 0.05) different from untreated control bolts. A bark surface assay indicated that 2% carbaryl killed < 50% of thebeetles at 24 h. Filter paper assay showed that the LC50 value was 0.07% and 0.01% at 24 and 48 h, respectively.