What is That in the Trees?

Have you ever driven down the street and wondered what the heck that is in the trees? Huge web like nests that show up every late summer! You wonder if is there anything that can be done about it!
Well, let me introduce you to the Eastern Tent Caterpillar. The Eastern Tent Caterpillar (Malacosoma Americanum) is more a nuisance than a threat. While heavy infestations can cause serious defoliation, Eastern Tent Caterpillars rarely kill trees except those already weakened by disease or climate and environmental stresses. These caterpillars get their name from the ugly tent-like nests that they spin in the crotches of host trees. They are native to North America east of the Rockies.
The preferred tree for these pests is the black cherry but they will also infest other cherry trees as well as fruit trees such as apple and a variety of shade trees.
Eastern tent caterpillars are black and hairy with a white stripe and a series of blue dots along the length of the body. At maturity, they range from 2 to 2 ½ inches (5 to 7 cm) in length. The moth is reddish in colour with white bands on the forewings. Females can be double the size of the males with a wingspan of 2 ½ inches (7 cm). Just in case anyone really cares!
Eastern tent caterpillars survive the winter in masses of 100 to 300 eggs noticeable as shiny black bands encircling twigs. Eggs hatch in spring at about the same time as the host tree comes into leaf. The young caterpillars then begin to consume leaves and spin the characteristic ‘tent’ nest in the crotch of the tree. The nest continues to grow as long as the caterpillars keep feeding. When the caterpillars reach maturity, after about six weeks, they pupate in silken cocoons visible on trees, on the sides of buildings and on fences. Moths emerge in July to mate, lay eggs and then die.
There is some hope if they bother you that bad. Eastern tent caterpillar infestations rarely threaten the lives of trees so control is generally for aesthetic purposes. There are commercially insecticides available to combat these insects. Consult with a local landscape or garden professional for details. Tents are sometimes burned or otherwise destroyed at night after the caterpillars have returned from feeding. However, given the dangers involved, this is not generally recommended. One easy and cost-effective prevention method is the use of TreeHelp Bug Bands. These sticky traps prevent tent caterpillars and other crawling insects from reaching the foliage from the ground.

All information referenced from: http://www.tent-caterpillar.com