H. euryalus rearing tips?

[Crake]

Hi all.

I've just received a batch of 40 Hyalophora euryalus eggs—courtesy of Bill Oehlke—and am a bit apprehensive about their potential survival odds. I've learned the hard way that most Hyalophora species are disease-prone—and therefore should not live in highly humid/crowded conditions—but I'm also concerned that they'll desiccate in the scorching summers of the central valley. 

If anyone has any experience raising this species, any advice would be greatly appreciated—I'm open to experimentation.

(Local potential hosts include madrone, willow, and sweetgum.)

[evra]

I’m rearing about the same number of H. euryalus from a female I collected a few weeks ago on cuttings of Brazilian pepper tree. Currently they are L2 and it is quite easy and basically the same as rearing H. gloveri, a species I have reared many times before. It’s pretty much just a matter of keeping them well ventilated, and on fresh cuttings. Crowding isn’t really an issue if the humidity is low. About 20-25% wouldn’t accept the host, but the rest are doing well.

[leptraps]

I raise the vast majority of my silk moths in screen sleeves. The number of parasitic flies the successfully lay their eggs on the larva when they come near to the screen or in contact with the screen.

[Crake]

Apr 15, 2021 13:04:36 GMT -8 leptraps said:

I raise the vast majority of my silk moths in screen sleeves. The number of parasitic flies the successfully lay there eggs on the larva when it come near the screen or in contact with the screen.

They're certainly crafty...

I do have a wide variety of screen cage sizes, so I suppose I'd be able to enclose a small cage within a large one to negate the risks.

[mothman55]

I have reared silk moths in sleeves on trees as well as on cut food in cages. Most of my frustration has come from the outdoor sleeves. I have had predators chew through triple sleeves to get to the larvae, especially when they are in later instars. They are not visible as there are 3 layers of sleeve, but the predators can still locate them. I have also had great success some years with outdoor sleeves, and the workload is considerably less, but if what I am rearing is of great value to me, I no longer risk them outdoors. Indoors or in rodent proof cages outdoors on cut food or plants in pots is safest in my experience. It might be mice, chipmunks, birds, wasps, or all of the above, but often they will find a way, and its generally when most of the work is done and they are in 4th or 5th instar that the attacks take place.

[kevinkk]

I'll jump into this one.

I've raised Hyalophora euryalus from wild ova a number of times. I use cherry, and I've also used Ceanothus victoria. Keep them outdoors,
I used sleeves, crowding never was an issue, but I would keep perhaps 8-10 larva in a sleeve about 20 inches, sometimes bigger,
depending on the branch.
I live on the Oregon coast, and it never gets hot, but the moth's I've caught in the wild come from a drier and warmer area of the state.

Mortality should be zero, with proper conditions, the only time I've had an issue, was trying to raise them indoors on potted ceanothus,
and most perished from some unknown pathogen, which I was able to save two larva from by moving them outside, and spraying the
larva with a disinfectant- Oxine.

Just follow the normal rearing- clean the frass, give them fresh food and they should be fine.

If you do see any disease, get rid of the larva, you can put it into it's own sleeve far from the others, but without treatment, they're usually
doomed, the particular ailment was a leaking of dark fluid from the mouth parts.

I've also tried, without success the following- Apple, and Alnus rubra
Stephen Stone lists a bunch of possible hosts, but Apple is one of them, as well as A. rubra-

[leptraps]

Should you wish to use a very strong but flexible screen, use Lumite Screen. Lumite is a plastic coated nylon screen. I have used it in my Bait Traps for over 15 years. Not even field mice can chew holes in it.

These Bait Traps allow me to collect 24-7-365. Then again, I collect moths, virtullay all Macro Moths and several families of Micro Moths. And, for what it is worth, I am retired and a widow. I can now collect 24-7-365.

[kevinkk]

Hyalophora are prone to infections, I've lost H. gloveri to the same black liquid death, as far as humidity- for me, right now it's 62%
outside, and that's unusual, normally it's much higher.

The places I've caught wild euryalus are drier, and warmer, sometimes into the high 80's and 90's, as long as you have shade for them,
heat shouldn't be a problem. Maples, alder, willows and ceanothus are common plants in the spots I've collected euryalus, here in Oregon,
and in northern Calif.

I think it's just a matter of clean and airy.

Parasites, here on the coast are virtually unknown, because there aren't any hosts for them probably, I've never had a problem outdoors here
with parasites, or predators.

If you don't have a copy of Stone's book- he does list Arbutus, Liquidamber and Salix sp., but it is an old book and he lists plants that will
not raise larva to maturity in more than one instance.

[Crake]

Apr 15, 2021 18:58:41 GMT -8 kevinkk said:

Hyalophora are prone to infections, I've lost H. gloveri to the same black liquid death, as far as humidity- for me, right now it's 62%
outside, and that's unusual, normally it's much higher.

The places I've caught wild euryalus are drier, and warmer, sometimes into the high 80's and 90's, as long as you have shade for them,
heat shouldn't be a problem. Maples, alder, willows and ceanothus are common plants in the spots I've collected euryalus, here in Oregon,
and in northern Calif.

I think it's just a matter of clean and airy.

Parasites, here on the coast are virtually unknown, because there aren't any hosts for them probably, I've never had a problem outdoors here
with parasites, or predators.

If you don't have a copy of Stone's book- he does list Arbutus, Liquidamber and Salix sp., but it is an old book and he lists plants that will
not raise larva to maturity in more than one instance.

Thanks for the information. Turns out the "euryalus" larvae were actually (sub)species/hybrid kasloensis. I tried experimenting with rose, alder, willow, madrone, birch liquidambar, etc.

Oddly, none were accepted and I resigned myself to raiding the local nurseries for ceanothus, which they took to immediately.

I also discovered—much to my dismay—that the hyper-arid climate of the is inhospitable to them. Only a few larvae desiccated, but I've transferred the remaining brood to an airtight enclosure until such a time as they are better able to retain moisture. 

Until that time, I'll be keeping them as sanitary as humanely possible...

[kevinkk]

I only know one person that has offered that "subspecies", in Wild Silk Moths of North America, it's listed as a separate species. at any
rate, at least they're eating for you.
If you don't have access to the book, try Matthew Campbell at Sagebrush Butterflies.com, he's got an ad right now for Papilio mutlicaudata,
I know he's raised this one before.
The cocoons will certainly need some very cold temps later on if you get them to maturity.

[papiliotheona]

The one time I tried euryalus they were a nightmare for me. IMO, just about all the big silkmoths with the possible exception of A. luna are much harder than most butterfly larvae, even many of the Papilio.

[exoticimports]

I’ve had zero problems raising local species, and being lazy about it. Luna, Polyphemus, Promethea, cecropia. All indoors. I think a lot has to do with environmental conditions. I tried euryalis and they all died.

[evra]

I haven’t had many issues with these. I have 3 spinning cocoons right now and 2 last instar larvae. The rest have already spun.