Tomicus piniperda (Coleoptera : Scolytidae) emergence in relation to burial depth of brood logs

The pine shoot beetle, Tomicus piniperda (L.), is an exotic pest of pines, Pinus sop., that was first found in the United Slates in 1992. A federal qu arantine currently regulates movement of pine Christmas trees and pine nurs ery stock from infested to uninfested counties. The current national Pine S hoot Beetle Compliance Management Program requires T. piniperda-infested br ood material to be disposed of by burning, chipping, or burial. The burial option requires that the infested pine material be buried at a depth of at least 30 cm. We tested this requirement by burying logs with similar levels of infestation at 0, 15, 30, 15, 61 and 76 cm and then monitoring for T. p iniperda emergence. Logs were buried at two times during larval development (early and late) and in two soil types (sandy loam and loam). Emergence pa tterns from the two soil types were similar. Overall, 1,747 T, piniperda ad ults were collected from the 24 exposed control logs, but only 34 adults fr om the 120 buried logs, including 24 adults from logs buried at 15 cm, eigh t adults from 30 cm, one adult from 45 cm. and one adult from 61 cm. In com paring mean emergence density from buried logs with that of exposed logs, 9 8.6% mortality occurred at 15 cm, 99.5% at 30 cm, and >99.9% at greater tha n or equal to 45 cm. Mean date of T. piniperda emergence to the soil surfac e was affected by burial depth and burial date, but not soil type.