How to avoid tachinid parasitism

[Cuauhtemoc Mendez]

Hi every one. I use to breed monarch caterpillars in cage (to avoid parasitism) but the whole last two cages were parasitized and I actually got them from eggs.
I put them on live asclepias but those are inside of a big cage (closed), although there are tiny green aphids below leafs but I used to think aphids don't parasitize.

Could you please give us an advice?

[Dale McClung]

Which parasites are you referring to? Are the eggs wild collected?

Dale McClung

[Dale McClung]

I see in the subject line you mention tachinid flies. Most tachinids have to make contact with the caterpillars, but some simply as noted below may lay eggs on the plant material to be consumed.

Yet another strategy of oviposition among some Tachinidae is to lay large numbers of small, darkly coloured eggs on the food plants of the host species. Sturmia, Zenillia, and Gonia are such genera.
<https://en.wikipedia.org/wiki/Tachinidae>

If your plant material as I read is protected, in opening and closing a door, you may have let a fly in. The eggs themselves are to my knowledge not directly attacked by the fly.

Dale McClung

[Cuauhtemoc Mendez]

Thank you Dale for your comments. Is there a way to kill any fly's eggs from the plant (I mean those eggs that may be out of sight) ?
I'm almost sure I read somewhere that there is a way to wash the food plant leafs with certain liquid.

[Dale McClung]

On 10/28/16 5:55 AM, Cuauhtemoc Mendez wrote:

Thank you Dale for your comments. Is there a way to kill any fly's eggs from the plant (I mean those eggs that may be out of sight) ?
I'm almost sure I read somewhere that there is a way to wash the food plant leafs with certain liquid.

Very weak bleach water, but tropical milkweed is difficult since its leaves wilt substantially if the solution is too strong or left in too long. You'll have to experiment with trial and error. I use .025% of the diluted active ingredient sodium hypochlorite for five minutes for plants. The time may not kill eggs as I am basically cleaning the plant material and reducing bacterial and fungal presence. If there are eggs present, you may be able to see them with a magnifying glass, but they I am sure are very small I can not tell you what they look like except amber colored eggs in a group are lady but eggs not tachinids, and the plants may not directly be the source.

Dale