Finally, almost four month out of cold storage, our imperial moths (Eacles imperialis) are eclosing. They normally don't fly until mid-summer in the wild so God knows what types of cues they take. Its already a mystery for earthen pupaters in general since things like photoperiod and temperature have less of a presence underground. Anyway, we have determined that all of our remaining pupae are now going to eclose more or less on sync. 

Today was the second of two females that recently eclosed. The first was slightly crippled and much smaller than this one. Again, it seems that they are phenotypically intermediate between Satuniids and Sphingids. The abdomen shape and genitalia is very similar to those of female sphinx (Sphingidae), but the wings are clearly Saturniid-like both in shape and the spots at the center of each wing piece. Unlike the males, this female has a lot less brown and a lighter shade of brown, especially on the forewings. Interestingly, it looks that have more of the freckles. 

The male that emerged a few weeks earlier has already died, unfortunately, and it looks like the only male pupa we have left is not due until another several days. However, based on the shape of the genitalia (not easy for hand-pairing!) and the fact that they probably don't pair readily in captivity, our chances of pairing these is quite slim anyway. 

One of our imperial moths (Eacles imperialis) sporadically eclosed today. Stock originated as eggs from New York, August 2016.

Well, this is pretty ridiculous. Three months after taking out of cold storage, one of these imperial moths finally decided to come out. The rest don't even look close. We have no idea why this one only eclosed until now and why the others still haven't - they should've came out long ago. True that they normally eclose in the summer naturally, but in captivity they should eclose only about a month after overwintering. The humidity shoudn't have been the problem, as we sprayed them regularly upon taking them out. W

It looks like we will have to forget about pairings and eggs now because we have no idea when the rest of the few pupae will eclose, but at least we have this nice looking male to look at. It is definitely not considered large for this species, as the larvae were reared on pine and produced small pupae, but the patterns are still nice. The yellow is very flashy, and the brown patterns and freckles add a nice touch. The underside is just yellow. Like other Saturniids, there is a spot at the center of each fore and hind wing, though it is not very developed and inconspicuous on this species, being small and brown. The wing shape is quite broad, and the forewings are pointy at the tip unlike silk moths which are usually rounded The body is tapered, and the eyes head is quite small, with small eyes hardly visible through the dense scales. 

​Authors
Alan Liang

We have taken our Eacles imperialis (imperial moth) pupae out of cold storage for eclosion.

Last year our imperial caterpillar rearing did not go so successfully due to it being late in the season and using poor pine hostplant. Hopefully, this year we will have another shot at it with these few pupae from last year's rearing. We plan to use sweetgum (Liquidambar) this time, which is just now starting to regrow its leaves around here. This should be a much better host by default due to being deciduous and not evergreen, not to mention the leaves will be much better quality early in the season. 

The pupae we have just taken out are all healthy and well, and should hopefully eclose five-six weeks from now meaning it'll be the beginning of May. Then comes the tricky part - pairing them. This species does not mate readily in captivity and will most likely need to be hand-paired which can be difficult depending on the males. Hopefully, we can manage to get at least one pairing which will supply us was plenty enough eggs for a year's rearing. 

It's a little late to begin doing so, but we finally got around to overwintering our diapausing pupae in the refrigerator at 40 F (4-5 C). The species we were sure would need this overwintering treatment were cecropia (Hyalophora cecropia), polyphemus (Antheraea polyphemus), imperial (Eacles imperialis), modest sphinx (Pachysphinx modesta), achemon sphinx (Eumorpha achemon), and white-lined sphinx (Hyles lineata) since the stocks orginated from regions with very cold winters. The only diapausing Saturniid/Sphingid pupa we didn't put in the fridge was Smerinthus ophthalmica since it was  obtained locally and it does not even get close to 40 F here.

​To overwinter the pupae of the six mentioned species, we simply dumped them all in various airtight contaners lined with paper towels with a drop of water. Dissapointingly, when we weighed the cecropia cocoons just to see if any had died since the time that they spun in July and August, we discovered two had lost a significant amount of mass and were therefore likely dead. All the other pupae/cocoons of the other species seemed alive. We will probably take them out of the fridge once the trees start growing leaves again (March or April 2017) and will check on them every few weeks just to make sure no mold forms. 

- Alan

Rearing Notes 9/28/16-10/23/16:

- Alan

Rearing Notes 9/15/16-9/27/16:

- Alan

For three whole days we have been waiting for the fourth instar Imperial caterpillar that entered apolysis on 9.11 to ecdyse. When we checked in the late afternoon today, it had just done it. The general appearance if similar to the previous instar. However, the four thoracic horns are even smaller and stubbier in relation to the body and have a rough, bumpy texture. The horn on A8 is very small now and the other scoli along its body are still very small and hardly visible under the now very long and dense hairs. As for coloration, this individual is yet still a black form but with orange patches around the spiracles. In the teneral state, the horns and other heavily sclerotinized areas were pink, but turned black once tanned. The head capsule is black with two yellowish-white streaks down the middle. It's rather surprising to us that there is absolutely no diversity in color among our Imperial caterpillars despite that color variations (green, orange/brown, black) are supposed to appear starting in the fourth instar. All our fourth instars are the black form and our only fifth instar is still a black form.

This individual spent roughly 10 days in fourth instar from 9/4-9/14. It spent approximately 6 days in the third instar from 8/29-9/4, 6 days and 12 hours for second instar from 8/23-8/29 and 7 days for first instar from 8/26-8/23. 

- Alan

Rearing Notes 9/5/16-9/13/16:

- Alan

Yesterday, our oldest third instar Imperial caterpillar entered apolysis for fourth instar. Throughout most of the day today, it was still in apolysis with its head capsule quite loose. However, some time during the evening, it ecdysed into a black form fourth instar. We were assuming it would probably be a brown or green form, but it seems we were wrong since this individual is pitch black in color -- even darker than it was last instar which was already very dark. Its head capsule, body and horns are all completely black. Asides from color change, its white hairs are much longer and thicker, thus making them very easy to see, especially on the black body. Shape wise, there are some proportional differences. All horns/soli on the body have been reduced from last instar. The four large thoracic horns are now short and thick and are uniform in color from base to tip. The large middorsal horn which used to be the same six as the thoracic horns is now reduced into a tiny spike that is almost unnoticeable. All the remaining small scoli along the body are now almost completely gone and cannot be seen through the long white setae; they will likely disappear completely later in the instar as the body gets plumper and stretched. We were somewhat disappointed that this one became a black form since its not a very attractive color, though we will definitely see all the color forms after the others molt into fourth instar! This individual spent approximately 6 days in the third instar from 8/29-9/4 which is quite fast since  second instar lasted 6 days and 12 hours from 8/23-8/29 and first instar took 7 days from 8/26-8/23. There are currently 3 more third instars in apolysis which will probably ecdyse tomorrow or the day after.

- Alan

Rearing Notes 8/30/16-9/3/16:

- Alan