Unique Insects of Late Winter

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Have you given any thought to winter bug-hunting? There are a few hardy creepy crawlies that one may observe in the winter, especially spiders and beetles, but there are a handful that you will encounter only from winter to early spring, so now is the perfect time to go looking for them. It’s no surprise that the word “winter” or “snow” is often part of their common name. They are generally very small insects (3-10mm) and therefore most easily seen when walking on snow. These cold hardy individuals are active when temperatures are at least 25F and, if a bit warmer, can be more numerous. Julie Lisk and Tom Murray provided the expert information for this guest blog post, which will help you spot these ephemeral and exciting invertebrates for yourself! 

With its elongated beak and ominous common name, the snow scorpionfly, a member of the Boridae family, is not to be feared. It is neither a scorpion nor a fly and is flightless. At only 3- 5 mm long, it lives a quiet life among the forest floor feeding on mosses, where it also lays its eggs. In winter males walk on the snow in search of mates. When startled, they will jump straight up and land with legs folded to resemble a speck of dirt.

An insect with a shining bronze carapace, hook-like mouthparts, and a pointed tail sits facing left against a white background.
Though they look and sound fearsome, snow scorpionflies are harmless and fascinating forest insects that love moss. Photo credit: Tom Murray.

Winter craneflies of the Trichoceridae family can often be commonly seen flying in winter and early spring. They can be confused with mosquitoes but are distinguished from them by the presence of 3 ocelli (extra eyes) on the top of their head, and thankfully, mosquitoes are typically not flying in late winter. 

A gangly, long-legged insect with delicately veined wings folded against its back and tiny antennae is centered against a backdrop of white.
Their resemblance to mosquitoes gives crane flies a bad reputation, but these “skeeter eaters” are actually totally vegetarian and cannot bite nor sting at all. Photo credit: Tom Murray.

Stoneflies are common throughout New England and members of the Capniidae and Taeniopterygidae families are active in winter. For example, the winter stonefly (Oemopteryx glacialis) and small winter stonefly (Allocapnia maria) are two species one might see. As immature nymphs they are aquatic – their presence is indicative of clean, well-oxygenated water, and when fully developed they crawl onto land in later winter and early spring to emerge as adults. Look for these seemingly-delicate creatures walking on the snow and ice near the stream edge in search of food and mates.

A squat, crawling insect with long antennae and two tails crouches with wings neatly folded over a brownish-black abdomen.
Stonefiles like this one are one of the best indicators of a clean, healthy cold-water ecosystem. Photo credit: Tom Murray

Lastly, an insect you may have seen on late winter walks are snow fleas, also known as springtails. The most readily seen species is Hypogastrura harveyi.  They have a forked appendage (furculum) that allows them to jump like a flea. They shelter beneath the snow, but on warmish winter days they come to the surface by the thousands, and are typically noticed in depressions, such as a footprint in the snow. This species can be seen at other times of the year but is most readily visible against the snow.

A human footprint in the snowy woods with hundreds of tiny black specks scattered around.
Like little hopping grains of pepper, snow fleas congregate around small depressions such as human footprints in the snow. Photo credit: Tom Murray.

So, on your walks, keep your eyes open for these winter wonders – spring is not long away! As these insects are often no larger than a grain of rice, a hand lens is recommended to help you see their complex structures up close; alternatively, you can use the opposite end of your binoculars. The photographs featured here were taken with a macro lens by Tom Murray.