Felton L. Hastings

Carbaryl: A Review of Its Use Against Bark Beetles in Coniferous Forests of North America

Abstract We reviewed the application of carbaryl (1-naphthyl N-methylcarbamate) against bark beetles (Scolytidae) in forest trees (Pinaceae) of North America. Our objective was to encapsulate carbaryl’s 30-yr history of successes and limitations against these beetles and to present appropriate safety and environmental information that relates to this usage.

Predation of Gypsy Moth (Lepidoptera: Lymantriidae) Pupae in Three Ecosystems Along the Southern Edge of Infestation

Abstract The predation potential of small mammals, in particular mice, Peromyscus spp., and invertebrates, was evaluated from 1992 to 1995 near the leading edge of gypsy moth, Lymantria dispar (L.), spread into the southeastern United States. Two study sites were established in each of three geographic areas: the coastal plain, Piedmont, and mountains. All sites were mixed hardwood stands with varying amounts of oak, Quercus spp., and all were classified for gypsy moth susceptibility. Small mammal density was estimated using Sherman live-traps and pitfall traps within these 4.68-ha sites in early and late summer. Each site contained 75 trapping stations located on a 25-m grid. Predation was measured by offering freeze-dried gypsy moth pupae near trapping stations at four heights (0, 0.25, 1.0, and 2.0 m) on different tree boles. Pupal predation was monitored for three consecutive nights. Vertebrate predation was positively correlated with good mast production in the previous autumn. Predation data showed that when mice were at high densities they were the major source of pupal predation. However, within these southern sites, when densities of Peromyscus spp. were low, predation by invertebrates was occasionally greater than predation by vertebrates. These data suggest that in some years invertebrates may retard gypsy moth buildup when small mammals are scarce due to mast crop failures.

Toxicity of Carbaryl toward the Southern Pine Beetle in Filter Paper, Bark and Cut Bolt Bioassays

Loblolly pine bolts sprayed with 2% carbaryl (Sevimol® 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 mines 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 the beetles at 24 h. Filter paper assay showed that the LC50 value was 0.07% and 0.01% at 24 and 48 h, respectively.