Hyalophora euryalus Egg Hatches

One of our ceanothus silkmoth (hyalophora euryalus) eggs has hatched from our batch of 42. These are of northern California origin

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We weren't really expecting this, but our Hyalophora euryalus eggs began hatching this afternoon, but only one. Today was extremely cold for this time of year here, with much rain and wind. We thought the low temperature would push back the hatch date for these eggs until next week as most of our other species have been growing very slowly.

Prepared or not, we were still excited about the hatching as this is such an incredible species. The newborn larva is black with pinkish dorsal thoracic scoli and yellow dorsal abdominal scoli. This is the usual dorsal scoli color scheme of euryalus in the early three instars. These dorsal tubercles are all quite large in relation to the larva's body, especially because of their very long tufts of yellowish pink setae. The lateral sets of scoli are undeveloped and look like small black spots and the spiracles are white circles but very small and hard to see. The head capsule is shiny black. Looking at it up close, the larva actually resembles the mature larva of the species quite a bit due to the scoli, but it has a black body rather than a green one.

For food, we went and got some very large leafed cuttings of a ceanothus variety (probably C. griseus) and also a willow leaf to offer the newborn larva. We let it wander on both hosts but it seemed uninterested in feeding on either until dark came, which is typical behavior for most newborn Saturniid larvae.

When we checked late in the night, it had crawled onto the ceanothus and looked pretty content so it will probably settle on it. This is exactly what happened last summer when we offered our newborn euryalus both ceanothus and willow as food choices - the larvae all preferred the ceanothus. This seems a little odd as both seem like very commonly utilized hosts in the wild, so willow should definitely work. We'd probably have to take out the ceanothus and only offer the larva willow for it to settle down on it. Willow seems like a nicer quality and more convenient host for rearing these on, but ceanothus should probably do just fine, so we'll just let this larva be for now. We might try to get some larva on willow when more hatch though.

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​Authors
Alan Liang

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