They slither in silence, drape trees in silk and chew through lively leaves. This year, the forests of Ontario are full of a very distinctive, creepy crawler - the tent caterpillar. Eastern tent caterpillars are appearing in large numbers across the province marking what experts describe as an ‘outbreak year’ for the species. While noticeable, the current outbreak is not as severe as previous ones, according to Dan Rowlinson, forest health field coordinator with Ontario’s Ministry of Natural Resources. According to the Government of Ontario, periodic outbreaks occur roughly every 10 to 12 years and typically last three to six years in a particular areas. The tent caterpillar, often mistaken for their close relatives; the spongy moth, is known for having a similar looking larvae. If you are planning to spend time in wooded areas or have a few camping trips in the summer books this year, here’s what you can look out for: Their appearance is distinctive, they have hairy bodies marked with blue and black patterns, and a row of keyhole-shaped spots running down their backs. These insects feed on the leaves of hardwood trees. While their preferred food sources include cherries, apples, and serviceberry trees, they can also be found on other hardwoods, according to iNaturalist.org. Their eggs are laid in late June or early July in a shiny black mass that encircle twigs. Heavy infestations can lead to complete defoliation, according to iNaturalist.org, but most healthy trees are able to recover especially if defoliation doesn’t occur in consecutive years. “They’re just in the tiny larval stage right now. So, they’re just starting to feed on the aspen and the poplar trees, shared a field coordinator with the Ministry of Natural Resources. When you are outside and you see the sudden presence of so many caterpillars, don’t be alarmed outbreaks are a natural part of the forest cycle. For now, residents can expect to see more of these insects throughout the early summer, as the caterpillars complete their feeding cycle before pupating and emerging as moths later in the season.
