Deodar Weevil (Pissodes nemorensis)
From Bugwoodwiki
Anonymous. 1989. Insects and Diseases of Trees in the South. USDA Forest Service. Protrotection Report R8-PR16. 98 pp.
Contents |
Importance
Deodar weevil (also called eastern pine weevil) adults and larvae can kill terminal and lateral branches, as well as girdle the stems of small trees. The weevil also vectors the pitch canker fungus, and its feeding wounds are infection courts for the pathogen. The weevil is found throughout the South and Mid Atlantic states. It attacks deodar and Atlas cedar, cedar of Lebanon, and various southern pines.
Identifying the Insect
Adult weevils are rusty red to grayish brown, have long snouts, and are about 1/4 inch (6 mm) long. The larvae are legless grubs, with a reddishbrown head. The life stages of the Deodar weevil are similar in appearance to those of the white pine weevil. Where their geographic ranges overlap, identification of the pest is usually based on the host species and the portion of the tree infested.
Identifying the Injury
During the fall, weevil larvae feed on the inner bark of leaders, lateral branches, and stems of small trees. Infestations usually remain unnoticed until the following January, when infested branches begin to turn brown. Small trees may be girdled and killed.
Biology
Adults emerge during April and May, and feed briefly on the inner bark of nearby trees, sometimes girdling stems and twigs before dispersing for the summer. Adults feed occasionally during the summer. Feeding activity increases just prior to and during the fall reproduction period. Females lay from one to four eggs in feeding punctures. The newly hatched larvae bore into the inner bark, where they construct winding galleries which girdle the stem. Winter is spent in the larval stage. Pupation occurs in chip cocoons in the wood during March and April. There is one generation per year.
Control
Keeping shade trees in a vigorous condition by proper watering and fertilization helps reduce their susceptibility to weevil attack. Insecticides can be used to protect high value trees.
Gallery
 Photo by Gerald J. Lenhard, Louiana State Univ, Bugwood.org |
