How to raise slug and nettle caterpillars, Limacodidae, and their relatives in the Zygaenoidea: Megalopygidae, Dalceridae, Aididae and Somabrachyidae.
Over the last three years I have been encouraging observers in iNaturalist to raise caterpillars of the Limacodidae in particular and to let me know what plant that they found the larva on. I'm a specialist in the Limacodidae in particular, but have also delved into research on the superfamily Zygaenoidea.
I'm hoping over time to develop a worldwide network to raise as many of the 2,000 species of Limacodidae, this rather charismatic moth group, as possible. Caterpillars, like their adults, present a number of challenges in being correctly identified by specialists. Like the adults, you have lookalikes that are indeed the same species, but also lookalikes that are different. In reverse, we also have very different looking caterpillars and very different looking adults that are indeed the same species. Sometimes, males look very different from females, as well.
I will be adding much more to this post in coming weeks, but for now, I do want you to use caution in raising caterpillars, particularly those covered in spines or hairs For example, in many Megalopygidae the spines lurk beneath the hairs.
Two basic ways to rear caterpillars are to place them in a container that is ventilated with tiny holes punch in the top or keeping them on their plant surrounded by fine mesh netting (best close to your home or where you trust your 'pillars won't be disturbed).
Handling: Don't try to grab spiny caterpillars directly. You can clip or pull the leaf off or cut off the end of a branch before placing them. You can also use a small brush to move a caterpillar directly to a container/leaf. This takes a bit of practice to have them grip on to the brush. For smaller caterpillars, a moist brush helps hold on to them, even from above.
Avoiding stings: Keep in mind, also, that it is the back of your hands and soft skin on your arms, legs and rest of body that are most vulnerable to stings, which can be quite painful.
Many of the nettle caterpillars also have tiny spines called caltrops at the base or tips of the subdorsal scoli (warts) on the sides and rear. These detach and can end up in your skin. Although these are not painful like the larger spines on the scoli, they are irritating to the skin. Often these caltrops do not form until the 3rd or 4th instar. The longer, often darker ones, on the rear segments form even later. I refer to these as deciduous spine patches. Both caltrops and the longer spines often are found in the outer layers of the the cocoon silk, so handling cocoons of the nettle caterpillars with rubber gloves is recommended.
