Birch Skeletonizer
Bucculatrix canadensisella Chambers

Hanson, T., and E. B. Walker. [n.d.] Field guide to common insect pests of urban trees in the Northeast. Waterbury, VT: Department of Forests, Parks and Recreation.

Lepidoptera: Lyonetiidae Hosts: Principal host is white birch, but other native and exotic birches may be attacked. Evidence: Look for late season browning of foliage and premature leaf drop. By mid-summer, narrow, serpentine mines are visible and white silken molting webs may be found on the undersurface of the leaf. By late summer, skeletonizing by the light green larvae causes conspicuous browning.

a. Early instar larvae of Birch skeletonizer are legless and feed within leaf tissues. Later instars have fully-functioning legs and feed externally. Note the presence of silken molting webs.

Life Cycle: Insects overwinter as pupae in ground litter. Moths appear from late June to late July. Eggs, which are laid singly on either surface of a leaf, hatch in about 2 weeks and young larvae enter the leaf and feed as miners. In 3 to 4 weeks, they emerge through the lower surface of the leaf and spin webs in which they molt. For the next 3-4 weeks, the larvae feed externally as skeletonizers, molting twice in silken molting webs (a). Full grown larvae (about 6 mm) drop to the ground to pupate.

Management: Defoliation occurs late in summer, when most growth is completed. Large-scale control is not usually warranted, though population levels on ornamental trees can be reduced by raking and burning leaves.

Photo Credits:

Figure a: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Waterbury, VT.

References:

Drooz, A.T. 1985. Insects of Eastern Forests. USDA Forest Service Miscellaneous Publication 1426. p 128;

Johnson, W.T. and Lyon, H.H. 1991. Insects That Feed on Trees and Shrubs. 2nd edition. Cornell University Press. p 220;

Martineau, R. 1984. Insects Harmful to Forest Trees. Agriculture Canada Government Publishing Centre, Supply and Services, Ottawa. p 118-120;

Rose, A.H. and Lindquist, O.H. 1982. Insects of Eastern Hardwood Trees. Canadian Forest Service Publication, Forestry Technical Report 29. p 65.

[ Contents ]     [ Previous ]     [ Next ]     [ Home ]