Stinging Slug Caterpillars

The gallery below features some of the commonest stinging caterpillars of North America.

Most caterpillars are harmless and play a crucial part in the ecosystem. However, there are a few species found in the US and Canada that have stinging hairs. Some individuals with particularly sensitive skin may show allergic symptoms and require medical attention. It is consequently advised to avoid direct skin contact with a caterpillar unless familiar with the species.

In North America and in many other parts of the world the caterpillars of the moth family Limacodidae are notorious for having stinging hairs

These stinging hairs and their oval shape have given rise to them being known as stinging slug caterpillars.

Perhaps the most common species of stinging slug caterpillar and the one most easily recognized is the Saddleback caterpillar (Acharia stimulea). This is also the largest Limacodid species being up to 3 cms compared with most others that are between 1.5-2 cms.

Some of the species such as the Spiny Oak-Slug (Euclea delphinii) have extremely varied coloured forms.

The extraordinary looking Monkey Slug, also known as the Hag Moth caterpillar, resembles a tarantula rather than a slug.

And despite also being a Limacodid species David Wagner in his acclaimed book Caterpillars of Eastern North America dispels the previously held view that it too stings.

Limacodidae-Slug caterpillars

Stinging Flannel Moth caterpillars-family Megalopygidae

Among the small number of Megalopygid species found in North America is the notorious Puss Moth caterpillar (Megalopyge opercularis), also known as the Southern Flannel Moth and appropriately named Asp. It is very hairy, almost cuddly, yet packs quite a sting. In recent years some have likened it to Donald Trump’s hairstyle. Less than 3 cms in length.

Another Megalopygid caterpillar with a sting is the brightly colored White Flannel Moth caterpillar (Norape ovina).

Other stinging caterpillars

Some sensitive individuals react to the hairs of several other, often hairy species of caterpillar. Among these are several species in the Lymantriidae moth family. These include The Browntail Moth caterpillar and The Gypsy Moth caterpillar.

The caterpillars of the Io Moth (Automeris io) and species of Buck Moth (Hemileuca species) are also known for having stinging hairs. These species are featured in their respective galleries – Large caterpillars of North America

Other North American caterpillar galleries

Large caterpillars of North America

Hairy caterpillars of North America

Loopers, Inchworms and Spanworms of North America

Butterfly caterpillars of North America

Other insects caterpillars of North America

Recommended caterpillar reference book

Caterpillars of Eastern North America – David. L Wagner.