Deodar Weevil Causes Pine Mortality in Louisiana1

Abstract

The deodar weevil. Pissodes nemorensis Germar, is known to infest the terminals of ornamental deodar cedar and cedar of Lebanon, Cedrus deodara and C. lebania, respectively, in the southern United States (Craighead 1950). Dietrich (1931) reported the weevil as attacking southern pine: however, only when the pines were either dead or greatly weakened and then only on the trunk and larger limbs and roots. Studies by Ollieu (1971) showed that this weevil caused 3 types of damage to apparently healthy pine trees in Texas. The 1st symptom described was a scorched appearance caused by adult feeding on tender shoots of the crowns of young loblolly pines, Pinus taeda shortleaf pines, P. echinata and longleaf pines, P. palustrus. This type of damage occurred predominantly on sapling-size trees, but also was observed on pole and small sawlog-size trees. The 2nd type of damage was leader killing by both adult and larval feeding. The 3rd type was branch-end flagging on pole and sawlog size pines. According to Dietrich (1931) the weevil attacks cedar trees and lays eggs in the late fall in the South. Development is completed during the winter. The adult weevils continue to be active throughout the winter and copulate and lay eggs during this time. Pupation occurs in March, and the brood adults emerge in April.