Regal Eggs Hatch

Our regal (Citheronia regalis) eggs have begun to hatch.

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Last night out regal eggs had turned completely black and pharate, and sure enough they began hatching around noon today. The larvae are absurdly large already, measuring 9 mm which is usually the size of most second instar Saturniidae. When they first hatched, the larvae were grey with small, pale orange scoli. After several minutes, however, they quickly darkened to black and inflated their scoli which also darkened to black. The six on the thorax and the middledorsal one at the rear are especially elongated and are clubbed, a look quite typical of many Ceratocampinae. 

When at rest, the larvae curl their heads to the side and the horns are folded up, but when disturbed they fan the horns out. They are very active larvae, crawling quite quickly. Some water and humidity seems to calm them down. 

​Shortly after hatching, we transferred all the larvae into plastic containers and offered them sweet gum (Liquidambar styraciflua), common persimmon (Diospyros virginiana), and Japanese persimmon (Diospyros kaki). The larvae normally feed on a wide range of hosts in their easterly range, mostly nuts out of the Juglandaceae  like walnut, pecan, and hickory, etc., but will also take several other hosts of which sweet gum and persimmon are probably more commonly used. Regional preferences definitely exist though, so possibly these two hosts may not be the best for this stock but they are really the only hosts we have for them. Also, out of the two persimmons, only the common persimmon is native to the larvae, not the Japanese variety, but here on the west coast the Japanese variety seems to be the only one that most people plant. 

After a few hours, it was apparent that larvae had initiated feeding on all three hosts, particularly the common persimmon. It's too bad this host is the hardest to obtain around here, as we could only find a single tree. Sweet gum on the other hand is practically on every other block, and Japanese persimmon is reasonably common as well. Hopefully, whatever host(s) we end up using, we'll have enough of it when they become voracious beasts.

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Authors
Alan Liang

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