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BLACK TWIG BORER
Wilted branch infested by BLACK TWIG BORER |
| Other |
Ambrosia Beetle |
| Species |
Xylosandrus compactus |
| Common Hosts: |
Apple Malus pumila
Boxelder Acer negundo
Camphor Cinnamomum camphora
Dogwood Cornus florida
Elms Ulmus spp.
Goldenrain tree Koelreuteria formosana
Pecan Carya illinoensis
Redbud Cercis canadensis
Red maple Acer spp.
Southern magnolia Magnolia grandiflora
Many other hardwoods |
Description |
Adult-- female approximately 1.6 mm long, light to dark reddish-brown; stout cylindrical body. Male rarely seen.
Pupa-- size of adult; creamy white.
Larva-- size variable, approximately 2 mm long when mature; dark brown head, yellowish-white body, legless. |
Importance |
First detected in Florida in 1941, the black twig borer is now distributed nearly statewide. Its aggressiveness in infesting healthy trees distinguishes it from most other AMBROSIA BEETLES. Severe infestations can significantly reduce the growth rate and alter the form of ornamental and shade trees. The stress of infestation plus other stress factors may induce death. |
Biology and Habits |
Adult beetles emerge from small branches and twigs by late winter-early spring, mate, and the females bore into shoots to lay eggs. The larvae feed on fungi growing on the tunnel walls. They pupate inside the damaged material; overwinter as adults. |
Number of Generations |
Several generations per year. |
Signs
of Infestation |
Foliage discoloration and/or wilting. Branch dieback. Small holes on underside of twigs and branches. Canker formation around holes. |
Control |
Prune off and destroy beetle-infested twigs and branches. Use an approved insecticide on high-value trees or those exhibiting notable levels of beetle damage. |
Bulletin No. 196-A | Printed October, 1983 | Contact the
Forest Health Section 
