Have you noticed these strange webs in the trees of Colorado?

Mysterious web sacks that have been spotted in the trees around Colorado, have left some people in the state scratching their heads. 

According to Colorado Parks and Wildlife (CPW), the webs are cocooning hundreds of tent caterpillars each. 

There are four species of tent caterpillar that call Colorado home including the eastern tent caterpillar, the western tent caterpillar, the fall webworm, and the sonoran tent caterpillar. During wintertime, masses of tent caterpillar eggs are laid in trees.

"The caterpillars become full grown in late spring. Most wander from the area of the tent and spin a white cocoon of silk, within which they pupate. The adult moths, which are light brown with faint light wavy bands on the wings emerge about two weeks later.," according to a report from Colorado State University (CSU). 

Though uncommon, it is possible for tent caterpillars to cause serious damage to their tree hosts. 

"Western tent caterpillar is the most common and damaging tent caterpillar, sometimes producing widespread outbreaks that have killed large areas of aspen," the report said. 

Tent worm populations are generally controlled by their natural predators, like birds, but insecticides are sometimes used as well. According to CSU, interference from humans is only necessary when there is "high levels of defoliation over several years."  

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