Advice for rearing Hyalophora euryalus in northern CA?

[pazu]

Hi all--

I raised a batch of Hyalophora euryalus caterpillars this summer, and they pupated a couple of weeks ago. Does anyone have any advice on care and storage of the cocoons over the fall and winter? I assume they normally overwinter in their cocoons, so I'm thinking I probably shouldn't keep them in the house indefinitely, since I wouldn't want artificially warm temperatures to cause them to eclose early.

Also, one of the caterpillars pupated without making a cocoon at all. Is there anything special I should do with the naked pupa? I think it's still viable.

Thanks in advance,
Dennis

[joee30]

Hi Dennis.

Hylophora euryalus does overwinter in their cocoons. If you were to keep them outside, you should make sure they can get ambient air, yet not get soaked if it rains. Also keep them somewhere animals nor curious kids will mess with the. If you do decide to keep them indoors, I put the cocoons in a tupperware container with paper towels, and put them in the vegetable crisper. Maybe some of the other members from this site can give you different tips, cause everyone rears livestock differently. What part of California are you in?

[oehlkew]

Hi Dennis,
When one of my normal cocoon spinners pupates outside of its cocoon, I wrap the naked pupa in a sheet of toilet tissue. I usually put the pupa on one corner of the tissue, aligned longitudinally perpendicular to the diagonal of the square tissue. Then I roll the pupa toward the opposite corner of the diagonal, wrapping in tissue as I go. Once pupa is wrapped, I moisten my fingers and lightly twist the tissue ends to close them.
When I take cocoons and pupae out of cold storage in spring, I loosen the head end of the tissue and have found that moths can push through the opening as if emerging through a normal cocoon. I treat all my Ceratocampinae and Sphingidae pupae with tissue wrap as described above.
I also store my overwintering stock in fridge crisper and usually put stock in the sealed plastic tubs in the vegetable crisper in late October. Please read
www3.islandtelecom.com/~oehlkew/zpupae.htm
If you take your euryalus cocoons out of cold storage in mid April to early May, the adult moths should eclose in sync with your local flight
in May-June in northern California. There is a much earlier flight (February-March) of this single brooded species in southern California.

Bill Oehlke

[pazu]

Thanks for the responses!

joee30, I live in Walnut Creek, not too far from Mt Diablo in east Contra Costa county.

oehlkew, I have plenty of Tupperware I can use, and we actually have crispers with humidity control in our refrigerator. Does the humidity setting matter if the cocoons are in a sealed container?

[joee30]

There is a lot of good H. euryalus habitat there. Currently, I'm in Reno, NV, which is not bad for Hemileuca. Keep up posted in how the overwintering goes. If you get some ova next season, I'd be interested in rearing some.

[pazu]

Update: I decided to try keeping the cocoons over the winter in a fabric mesh rearing cage in my garage.

As of 5/2/14, five out of seven cocoons have eclosed. Two males emerged about three weeks ago, and then a male and female last week, and then another male a couple of days ago. I have no idea why their emergence was so staggered, since they all pupated within days of each other. I also don't know whether the last two cocoons are viable or not.

All of the adults seem relatively small, definitely smaller than the female that laid the eggs they hatched from. Maybe I didn't feed the caterpillars enough?

The female has laid a number of eggs, so I guess I could try rearing another generation. To joee30, if you're still interested in ova, I would be happy to send you some, but I would first need some advice about how to detach them from the fabric of the rearing cage without damaging them.

[pazu]

OK, so I'm reviving this thread because I've just hatched another group of H. euryalus eggs (as of this morning, in fact). Oddly, the caterpillars seem strangely uninterested in the fresh ceanothus leaves I'm putting in their container and keep wandering randomly around instead. I think some of them may have taken a few nibbles, but nothing much.

Should I try them on a different food plant? Keep going on the ceanothus? I don't recall my last batch of larvae behaving like this. Will they starve themselves if I don't give them something they like?

[Adam Cotton]

A friend told me that many species of Saturniid larvae like to wander around for the first day after hatching before actually starting to feed. Perhaps in nature it is a way for larvae to be distributed around the tree the eggs were laid on, so that they don't interfere with each other when growing.

You mentioned above how your adults were smaller than the natural female parent. This is a common problem in rearing both butterflies and moths. Food plant leaf quality and the amount of interaction between larvae kept together (for non-gregarious species) are both important factors in the potential size of the pupae, and resulting adults. In the wild the non-gregarious larvae are generally well separated on host plants/trees but if reared together in a small cage or box every time they meet they waste eating time by interacting and moving around as a result. With most Saturniidae it is important to separate larvae as they grow to avoid this and also disease problems.

Most Lepidoptera larvae need succulent young leaves in order to grow large. If they only eat older leaves they generally don't grow as large. There are some species that can only eat old leaves though, for example Elymnias hypermnestra only eats the oldest shoots of the palms it feeds on. Young leaves contain a natural insecticide that would kill the larva if it ate them. Generally speaking lots of fresh young shoots are important for rearing larvae to large size.

Think of rearing larvae as if there is a clock ticking from the moment the larva hatches from the egg, and when the alarm goes off the larva will pupate regardless of how big it is. Any eating time wasted because the larva has to move means that the larva ends up eating less, and if the quality of leaves is inferior the larva cannot grow to its full potential. Larvae are not like us, in that if we eat less today we can compensate by eating more tomorrow. If they have to wait until fresh food plant is put into the box/cage they cannot make up the lost eating time.

Adam.

[bluemoth]

I have reared this moth before. I found out they will eat mazineta leaves. They prefured this instead of ceanothus. Also feeding sugar water to larva once or twice a week will give you bigger moths. This should work will with all sp. of silk moths. I used 1 part organic cane sugar to two or three parts water. I taped one side of petry dish { you can use a clean jar lid } to stiff cardboard. Then picked up the larva and place them around the dish so that their mouths are in the water, once they got a sip they would stay there drinking for a long time be for they turned away. Thy love that sugar water.

[admin]

Sept 18, 2013 20:39:51 GMT -8 pazu said:

Hi all--

I raised a batch of Hyalophora euryalus caterpillars this summer, and they pupated a couple of weeks ago. Does anyone have any advice on care and storage of the cocoons over the fall and winter? I assume they normally overwinter in their cocoons, so I'm thinking I probably shouldn't keep them in the house indefinitely, since I wouldn't want artificially warm temperatures to cause them to eclose early.

Also, one of the caterpillars pupated without making a cocoon at all. Is there anything special I should do with the naked pupa? I think it's still viable.

Thanks in advance,
Dennis

I have reared these many times down in So Cal. I just keep the cocoons indoors in a carboard box in my living room, misting them occasionally. Then put them in the refrigerator in a sealed plastic container from November 1st to March 1st for required diapause. They hatch about 30 days later after you bring them back to room temp.

Roll up the naked pupa in a paper napkin and scotch tape it into a tube for protection. Leave one end of the tube open open, the head end, so the emerging moth can crawl out.

[joee30]

Let me know if you rear some this next season. I would be interested in some ova if you have any.

[collector]

I raise euryalus every year.
I found Laurel sumac to work better than ceanothus.
I start them indoors then I sleeve them outside.
Once all pupate I bring them indoors until November, then I keep them in the refrigerator for 2 to 3 months.
Bedros