Fall Cankerworm – Alsophila pometariaCommon Name: Fall Cankerworm
Latin Name: Alsophila pometaria
Appearance:
The females of the Alsophila pometaria, often known as fall cankerworms, are large, winged insects ranging in colour from brownish to silvery.
The species’ males are grey moths with a few darker markings that create two lines across each wing. Eggs are very small and have the shape of a barrel.
A black line goes around the egg’s top rim, and there is a very small dark dot at the top. The caterpillars of the fall cankerworm are loopers, meaning there is a gap between the first six legs and the last four legs (prolegs) of their body.
This allows them to “inch” along as they crawl. These caterpillars can have a very light green colour with even more golden stripes, or they may have black lines running down the back and around the sides.
Host plant:
Fall cankerworms populate apple, birch, boxelder, dogwood, elm, hickory, and other hardwoods. They can cause severe defoliation of ash, basswood, red maple, sugar maple, red oak, beech, black cherry, and white oak.
Territory:
The fall cankerworm is a common native pest of hardwood trees in North America.
Damages caused by Fall Cankerworm:
Young larvae begin eating in the space between the leaf’s tiny veins. When larvae reach maturity, they eat the whole leaf, leaving just the midrib and main veins. This bug frequently defoliates the entire tree. If a tree is defoliated twice in a row, it may die, especially if it has been stressed by drought or bad site circumstances. Outbreaks often last between one and two years. Infestations in public places can be a nuisance, especially when adult larvae are silking out of the tree. Nymphs can be blown upon persons beneath afflicted trees on windy days.
Life history and Habits:
This pest has one generation each year. Larvae hatch from late April to early May, while leaves emerge from host tree buds. During a severe infestation, larvae can consume the leaves as quickly as they grow. After hatching, larvae achieve maturity in 5 to 6 weeks. When the larvae reach adulthood, they descend from the tree canopy on a silken thread. When they reach the ground, they spin a cocoon from silk and dirt particles. This cocoon contains the pupal stage. This species will continue at this stage from late October to early December when cold temperatures are expected. The female without wings climbs the nearest tree and mates with the man. After mating, females deposit around 100 eggs in tight rows in a single layer on smaller twigs and branches. This pest spends the winter as an egg.
