My first tachinid victim

[Mom2RJA]

One of my caterpillars died last night in its J position. I couldn't imagine what had gone wrong. This had been a perfectly healthy caterpillar with no sign of any illness. I was in a rush to leave the house this morning, so I didn't have time to dispose of the caterpillar. I just got home and went to take care of it, and I found two tachinid pupae and one larva in the jar. What is the best way to dispose of them?

Most of my monarchs have been raised from eggs, but this one was a tiny caterpillar when I found it. I'm amazed the flies get to them when they are so tiny. I don't think I've ever found one more than 4-5 days old, and this one was younger than that.

[Mona Miller]

viewtopic.php?f=6&t=2336&p=11421&hilit=tachinid#p11421
I think this topic covers what you are asking about the flies.

What are you putting on the top of your jars? Some times the flies get inside and they can lay through material like tulle.

What to do with the fly?
1. You can hatch it out and send it to Monarch Lab.
http://www.mlmp.org/
Monarch Larva Monitoring Project
Here's the contact info to ask for details:
http://www.monarchlab.org/contactus.aspx
2. You can flush it.
3. You can squish it with a paper towel and throw it into the garbage.

[Mom2RJA]

I sent a message to that lab to see if they want them. Thanks.

[Mom2RJA]

My jars had jar lids loosely covering them, not anything like tulle. And I haven't seen any flies in my house anyway. I'm sure the fly must have gotten the caterpillar before I brought it home.

[Mona Miller]

I just wanted to make you aware that these flies will seek out their prey wherever they are. The flies will come into your house because they can smell the frass.

[Mom2RJA]

How big are the flies? Are they big enough that I would notice them? They look different from normal house flies from the photos I've seen, but I can't tell from the photos how big they are. The only flies I have seen in our house have been a few fruit flies (and one big house fly that got in and was quickly swatted). But there haven't been any jars with covers that would let flies in anyway.

[Mona Miller]

They are not that big, but their eyes are big.

http://www.mymonarchguide.com/2008/01/d ... d-fly.html
This gives more details on their appearance.

http://pcmg.ucanr.org/files/114592.pdf
Tachinid Fly
ACTUAL SIZE: 3/8 to 1/2”
Feeds on caterpillars, Japanese
beetle and other insect
larvae.

http://www.nadsdiptera.org/Tach/Gen/tachintr.htm
This website has all the information that you might want to know about the flies. Yuck, Yuck, Yuck!