caterpillar disease, aka "the black death"

[kevinkk]

I am wondering if anyone has experience, advice, or a solution to a problem I've encountered several different seasons, on various food plants, indoors

and out, with caterpillars succumbing to a disease or virus that causes them to exude a blackish liquid from the mouth area, looking something like the

grasshopper "tobacco juice" we're familiar with from being junior bug hunters.. without the stress and worry experienced as adult bug hunters.

It's happened to me mostly with the Hyalophora, perhaps because that is the species I've raised most often, specifically H. euryalus, it's happened to me using

ceanothus, and cherry, most recently to some of my euryalus I have indoors on a potted ceanothus, the density is low- 6... at least there were 6, on a 3 gallon

plant, in a well ventilated cage, lighted well, as natural as I could get indoors. It has happened to different instars as well, there seems no rhyme or reason,

except the result, dead caterpillars, one by one. This has also happened to me with H. cecropia several seasons ago, sometimes it stops and only one will get

sick, but not everytime.

I will welcome any feedback on this topic, and will return your emails

[e-mail]

[jsleps]

I have had this problem with Hyalophora as well. I have also noticed that even in low densities the problem would occur, specifically H. euryalus.
Did you find any assistance on this topic?

[papilio28570]

Having reared cats for 40+ years, here is my advice:

If using potted plants, do a soil drench with hydrogen peroxide (ONE CUP added to One Gallon of water) to kill soil pathogens. If the plant is dormant for the winter, thoroughly spray the stems of the plant. The peroxide will also add needed oxygen to the soil and won't harm the plant.

If using cuttings to feed your cats, mix a 5% to 10% solution of bleach and water. Dip the cutting for about 30 seconds and then rinse thoroughly with fresh water. Shake excess water off and the cats do not mind that the leaves are wet...which will soon dry plus the leaves will absorb some of the moisture. Do not use collected rain water.

If using sleeves on plants outside, be sure that your sleeves were soaked in the bleach solution and thoroughly rinsed and dried before use each time. You can also spray the plants with the bleach solution and rinse immediately. Saturate the ground around the plants you use each year with the peroxide solution. Do this preferably before new leaves emerge each spring. Spray the whole area down with a fungicide after you rake up the leaves beneath the plants in the fall of the year. I use a wide spectrum fungicide you can purchase at any garden center which you simply hook the bottle up to your hose. I also save the bottle and fill it with bleach to spray large bushes or trees. You can do the same with hydrogen peroxide since the bottle mixes the contents with water as it is ejected. Be sure the bottle label instructs to use on 5000 to 8000 square feet and that the bottle has a built-in spray nozzle. This will properly proportion the chemical to a 5% to 10% range.

If using cages for rearing, they must be thoroughly disinfected before use with each successive brood of cats.

All of this will not guarantee 100% success, since many pathogens are dispersed on the wind, but it will greatly improve your odds year over year.

Any sick cats need to be disposed of at first signs of illness as many cat diseases are highly contagious and will leave a pathogen trail wherever they roam on the plant or enclosure. Isolate that enclosure away from all other enclosures right away.

Of great importance is that you wash your hands in peroxide or bleach solution and rinse every time before interacting with your cats or their enclosures. Keep a spray bottle near your rearing area for this.

I also noticed that you rear indoors and have this black death problem. Hate to tell you but you have to disinfect the whole room, walls, floor, door knobs and all.

[Adam Cotton]

"Any sick cats need to be disposed of at first signs of illness as many cat diseases are highly contagious and will leave a pathogen trail wherever they roam on the plant or enclosure. Isolate that enclosure away from all other enclosures right away."

You should also change the plant which the sick larva was sitting on, otherwise healthy larvae will be infected.

"I also noticed that you rear indoors and have this black death problem. Hate to tell you but you have to disinfect the whole room, walls, floor, door knobs and all."

One problem with rearing in boxes is insufficient air movement, this lowers the larva's resistance to disease and multiplies problems. If you can increase air movement it will help.

Also for non-gregarious Saturniidae you MUST separate larvae into individual boxes before 4th instar, and don't keep too many small larvae in the same box. It is also important to remove all frass daily and not allow condensation to build up on the box. The advantage of separation, as well as being more natural, is that if one does get sick it cannot contaminate another larva.

Adam.

[papilio28570]

Surprised this thread did't get more replies.

How many here actually rear local species?

[mothman27]

I am curious but have no answers.

[leptraps]

I have reared literally thousands of Colias. (Colias eurytheme & Colias philodice) I reared them on Potted Plants in cages. My biggest problem were mice. I finally replaced all the Nylon Coated Fiberglass Screen with metal screen.

I have also sleeved many moths and butterfly larvae. I never had great luck with indoor rearing. I have reared many Lyceanids indoors in plastic Containers covered with screen and never had a problem.