Ash Cambium Miner
From Bugwoodwiki
|
Contents |
Importance
Maggots of this fly mine in the cambium of tree boles and roots in the Eastern United States. They cause defects consisting of small, light to dark streaks evident in tangential cuts of wood or specks known as pith ray flecks, worm tracks, or glassworms as seen in cross-sectional cuts. Such defects cause quality degrade when the wood is used for veneer, cabinets, baseball bats, or tool handles.
Identifying the Insects
The larvae are long, narrow maggots, somewhat laterally flattened, and measure about 25 mm long when fully grown. Adults look somewhat like small, hairy houseflies.
Identifying the Injury
The maggots make long threadlike mines in the cambium of branches, boles, and roots. Mines are most common in the basal 90 cm of the trunk and in the roots within 1.5 m of the bole. Mining in living trees is detectable only by removing the bark. In lumber and veneer, mines appear as zigzag tracks lighter or slightly darker than the natural wood.
Biology
Eggs are laid in small twigs. Maggots mine in the cambium and inner bark down the stem and into the roots. Second-instar maggots overwinter in the roots. Full-grown maggots exit through the bark and form puparia in the soil. In the North, pupation occurs in May and June, whereas in Mississippi, it occurs from February to April. The life cycle is completed in 1 year.
Control
Dead maggots have been found in their mines following unusually cold winters. Other natural controls are unknown, and direct controls have not been investigated
References
Solomon, J.D.; Leininger, T.D.; Wilson, A.D.; Anderson, R.L.; Thompson, L.C.; McCracken, F.I. 1993. Ash pests: A guide to major insects, diseases, air pollution injury and chemical injury. Gen. Tech. Rep. SO-96. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 45 p.
