Leaf Feeders
Lee Townsend, University of Kentucky
Japanese beetles can feed on about 300 species of plants ranging from roses to poison ivy but basswood is one of their favorites. They usually feed in groups, starting at the top of the tree and working downward, and prefer plants that are exposed to direct sunlight. A single beetle does not eat much; it is group feeding by many beetles that causes severe damage. Adults feed on the upper surface of foliage, chewing out tissue between the veins. This gives the leaf a characteristic skeletonized appearance. For more information, see Entfact 451.
Steven Katovich, USDA Forest Service, Bugwood.org
Linden looper, an inchworm, is one of the caterpillars that can feed on linden. The underside of the caterpillar is yellow; alternating streaks of black, blue, and yellow run along the sides and back. The head is light brown. Eggs are laid in the spring and hatch at bud break. There is one generation each year.
Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org
Fall webworms are small hairy white caterpillars that live communally in thin silken webs at the ends of branches. They may leave the tent to feed individually as they get larger. While the webbing is unsightly, feeding damage is usually limited to limbs around the tent. Large established trees are not seriously affected by small to moderate infestations. The larval stage feeds for 4 to 8 weeks and may be found on a variety of hardwoods. The first generation occurs in late May and early June, the second generation is usually larger and active from July through September. For more information, see Entfact 424.
John Ghent, John Ghent, Bugwood.org
The caterpillar stage of the Hickory tussock moth feeds from July to September. Similar to other tussock moths, the hickory tussock has a hairy appearance and is black and white in color. They begin by feeding in groups before moving apart to find leaves. This caterpillar does pose a "stinging" hazard as contact with the hairs may induce a rash on susceptible people.
Natasha Wright, Cook's Pest Control, Bugwood.org
Joseph LaForest, University of Georgia, Bugwood.org
Basswood leafminer - As adults these small beetles have an interesting nearly rectangular body shape.They are 1/4 inch long and are red-brown with black streaks on their backs. they overwinter as adults and emerge in spring to skeletonize new leaves. They lay eggs that hatch in June. Larvae are leafminers that create blotch mines. Combined adult and larval damage cause whole leaves to appear ruined and unsightly.
A. Steven Munson, USDA Forest Service, Bugwood.org
Fall cankerworm is a looper caterpillar that can vary from light green with yellow stripes to green with a dark stripe down the back. Overwintering masses of about 100 eggs hatch in later April or early May; small caterpillars chew small holes in young leaves at branch tips. Larger loopers leave only the midrib and major veins. Fall cankerworms are about an inch long when full grown. Mature larvae descend from trees on silk threads to pupate in the soil. They emerge as adults during periods of freezing temperatures to mate and lay eggs on host plants. There is one generation each year.
Sap Feeders
Herbert A. 'Joe' Pase III, Texas A&M Forest Service, Bugwood.org
Giant bark aphid is the largest aphid in North America. This sap feeder can live on several tree species. Winged forms disperse from tree to tree. Wingless aphids occur in large colonies. These aphids produce a large amount of sticky liquid waste, honeydew, which drips onto objects below. Feeding by large numbers of these aphids can damage or kill small twigs. They are eaten by lady beetles and other predators.
Raymond Gill, California Department of Food and Agriculture, Bugwood.org
A mature female cottony maple scale is 1/8 inch long with a brown, flat, oval body. Infestations are most easily noticed during the summer when females produce white, cottony egg sacs that resemble pieces of popcorn on twigs. These scales also produce large amounts of liquid waste (honeydew) so leaves may be shiny and sticky and black sooty mold fungus may cover branches and the trunk. They spend the winter in an immature stage on twigs or branches and complete development in June when the egg sacs appear. Eggs hatch during June and July and crawlers move to the lower surface of leaves where they settle feed on sap for the rest of the summer. Just before leaf drop, the small insects will move back to twigs and branches to spend the winter. There is one generation each year.
Whitney Cranshaw, Colorado State University, Bugwood.org
Oystershell scales are about 1/10 inch long and resemble crusty accumulations of oyster shells on the bark. Their drab, bark-like appearance makes them easy to overlook, even on close inspection. Heavy infestations can kill twigs or branches. This scale overwinters in the egg stage under the waxy covering of the female. The eggs hatch and the crawlers are active from late May to early June.
Gerald J. Lenhard, Louisiana State University, Bugwood.org
Tuliptree scale is a large, 1/3 inch diameter, soft scale that infests tuliptree or yellow poplar, magnolia, and occasionally linden. Female covers can vary from gray to pink mottled with black. Large numbers of this hemispherical scale can give infested branches a bumpy or warty appearance and may cause branch dieback. Tuliptree scales produce large amounts of honeydew so leaves are often shiny or may be covered with sooty mold.
There is one generation of the tuliptree scale each year. They spend the winter in an immature stage with females maturing during late summer and laying eggs that hatch in August. For more information, see Entfact 435.