Hyalophora cecropia Eggs Begin to Hatch

Hyalophora cecropia eggs from the first two pairings have begun to hatch. We discuss our thoughts on what host plants we are considering to use for this year's rearing. 

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After two whole weeks, the eggs from the first two pairings (5/29) have finally begun to hatch. Nearly a hundred of the eggs from the larger of the two females and 20-30 from the smaller one hatched in the early morning. The hairy black larvae were full of energy and crawling around the petri for quite some time before we first saw them. Interestingly, it seems just from the eye that the larvae from the larger female are slightly larger than the one from the smaller female, and perhaps the eggs were slightly larger on average too. We have also noticed in the past that larger females not only laid more eggs, but had slightly larger ones as well (for some other Saturniids and Sphingids too).

As always, choosing the host plant for these larvae has always required quite a lot of thought over the years. We tend to choose whatever is the most convenient/abundant or what seems to be a commonly used/preferred host. To summarize, the first two years in California we used a non-native plum (Prunus) and apple (Malus) because we didn’t really have much else in their non-native range, which worked pretty well. Last year, here in Ithaca, we used wild black cherry (Prunus serotina) and Norway maple (Acer platanoides, an invasive maple variety). Serotina worked very well, which is consistent with what a lot of people who have reared this species have reported, but was rather inconvenient for us to get. The platanoides was not nearly as good, which was surprising since maples are supposedly one of the most commonly used hosts in the northeast and are extremely abundant here, though this was a non-native variety.

This year, we plan to stick with hosts that are abundant and close to where we live so we can sleeve them (that means no serotina). The platanoides didn’t work too well last year, but we aren’t ready to give up on maples yet, since we suspect the variety really matters. Boxelder maple (Acer negundo) is the other maple variety that is extremely abundant here, and is a native, much more vigorously growing tree. Vigorous plants typically make great hosts, and since it would be convenient for us to sleeve larvae on, we decided to give it a try.

We kept the larvae from the two pairings separate in plastic boxes and gave each a cutting of boxelder. To our surprise, the larvae crawled from the petri dishes onto the cuttings all by themselves and began feeding almost immediately. Believe or not, this doesn't actually happen too often with Saturniid larvae we have reared in the past. They usually wander around restlessly for at least a few hours and can take up to a full day to initiate feeding. The fact that they were so receptive of the boxelder is definitely a really, really good sign (they certainly were not like this with the platanoides). Perhaps this is indeed one of the most commonly used hosts for this species here.

By evening, the larvae had all settled comfortably onto the boxelder cutting and had formed loose aggregations. There was already an impressive amount feeding damage and frass in the container just from the past couple of hours and the larvae had already grown a bit. Boxelder may become our new favorite at this rate. We will probably keep them in boxes just for a little bit to get them started and will probably transfer them onto outdoor sleeves soon when the weather is better (it's been a rainy week here in Ithaca).

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Alan Liang​
​Alan Liang is a student at Cornell University in Ithaca, New York pursuing an undergraduate degree in entomology. He is co-owner and a main contributor of the Liang Insects blog and photographs.

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