By David Hawke -- "Beware the dagger moths! Beware the tussock moths!" is the cry that is going across the land this fall, and for good reason.
Some folks have ended up in the hospital with a major skin rash and pulmonary problems while many others are enduring numb fingers or itchy hands. But there are more critters than dagger moths of which to be aware.
It's not the adult moth that's the problem, it's those spiky, hairy, just-creeping-along caterpillars that cause the grief. In addition to the daggers, there is a large group called tussock moths, as well as numerous other poison toting caterpillars.
It is easy enough to see the stinging hairs protruding from the backs of these caterpillars, but what is not so noticeable (to the eye) are the barbs that coat these easily broken hairs. If the little fuzzy-wuzzy is crawling across your arm, the tiny hairs break and fall into the layer of perspiration that lines your skin; they stick and imbed like shards of fibreglass. Not only quite painful but also capable of triggering an allergic reaction in susceptible people.
This past month two of my colleagues were victims of the toxin found in an Io (pronounced EYE-oh) moth caterpillar. This is a big caterpillar with very obvious clusters of spines protruding from a lovely lime green skin; looks pretty but my-oh-my the reactions caused when physically encountered were noteworthy: One had part of her hand go numb for two days after picking it up (in a laneway-crossing rescue), while the other accidently brushed her arm on a camouflaged beast and was stung right through her sweater as if pricked by a hawthorn. Seriously not nice experiences.
I found a 1927 report on tussock moths and within were a couple antidotes for the rash, the more popular being a mash of purslane (Portulaca) leaves applied directly on the rash. If you have a nasty rash from an encounter with a caterpillar of either a dagger moth or tussock moth, this may be worth a try.
Despite the cooler temps of late, you still need to be aware of these caterpillars, as they have now woven a fuzzy cocoon to spend the winter months. If you touch this cocoon the tiny hairs are still volatile and may again cause a nasty burning rash on you.
This seems to have been a banner year for these caterpillars as they were so numerous that several shrubs were completely defoliated. While they usually eat the leaves of most deciduous trees, several dogwood shrubs were hit hard. And as you may have already noticed, there were caterpillars everywhere this year.
Even in early October we still have a milkweed plant in the yard that is hosting well over a dozen tussock moth caterpillars, and several dagger moth cats (that's the cool slang name for caterpillar) can be found on, around and under the deck. All will be searching for a quiet crevice to build a winter cocoon, so until the frost really settles in, they will be out there!
Perhaps the saying "look it up before you pick it up" is the best advice for dealing with these spiny crawlers. Although they may even drop down on you from a high branch, it's best to flick them off as soon as possible before those fragile hairs start falling on your skin or sweater. However, if you are experiencing a skin rash that lasts longer than a day, go see a doctor... untreated rashes can quickly manifest into something serious.
This article, despite the tone, is not to intimidate you from going out of doors; just be aware that these guys are numerous this year so it is likely that you will find a few on any outing. Take a look, take a pic, just don't take a poke with a finger.
David’s Notebook: The lovely warm weather of the last couple weeks has allowed many caterpillars to roam about finding that last bite of food before cocooning for the winter. But be aware that a couple caterpillars are causing grief to those who touch them.
© 2019 David J. Hawke