Birch Lace Bug
Hosts: Yellow and white birch, beech, maple, willow, mountain-ash
Evidence: These small, flattened insects live and feed on the underside of leaves. While the upper surface of infested leaves becomes mottled and discolored, the undersurface is littered with excrement, cast skins of developing immature lace bugs, and eggs (a). Heavily infested leaves turn brown and fall off. Nymphs and adults reach their highest populations in August.
Life Cycle: There are two generations per year. Winter is spent in the adult stage among leaf litter. In the spring, eggs are laid in groups of 4-10 on the lower surfaces of leaves in the axils of veins. Nymphs, which are dark brown, molt five times before reaching adulthood. Adults are about 4 mm in length, and have lacelike forewings (b).
Management: Control measures are not usually required for lace bugs on trees. If horticultural oils or other insecticides are used, the lower surface of the leaves must be sprayed thoroughly.
Figure a: Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, Morrisville, VT.
Figure b: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Waterbury, VT.
Drooz, A.T. 1985. Insects of Eastern Forests. USDA Forest Service Miscellaneous Publication 1426. p 64-65;
Johnson, W.T. and Lyon, H.H. 1991. Insects That Feed on Trees and Shrubs . 2nd edition. Cornell University Press. p 426-427;
Rose, A.H. and Lindquist, O.H. 1982. Insects of Eastern Hardwood Trees. Canadian Forest Service Publication, Forestry Technical Report 29. p 90-91.