Please ID this parasitic fly/wasp?

[JohnxII]

This hitchhiker killed my poor jumper without a clue... but what is it?

 

[Choobaine]

it looks incredible whatever it is! I'd keep it if you can work out what it needs. Looks fascinating!

 

[Spaceman_Spiff]

They're called Acroceridae!
The larvae of these flies develope as parasitoids in spiders (as you have witnessed)!
Interestingly, the larvae actively seeks out a host, not the adults!

Nice find and nice pictures! Sorry you had to loose a pet though!

 

[Black Widow88]

I have a couple of questions:

1. If the larvae seek out the host then where do they adults lay their eggs? That's something that I'm trying to work out but can't.

2. The long slimy thing behind what I assume is the pupa is the larvae right?

3. Is that the pupa in front of the worm like thing? Seriously I need to to explain the life cycle of these for me because this is confusing. :?

I was also wondering if all the species in Acroceridae do this?

Black Widow88

 

[Widowman10]

wow! that is amazing! sorry for the loss of the jumping spider, but the progression of the pics is great! :clap:

 

[lucanidae]

Textbook Acroceridae, the small headed flies. I had a friend rear one out of a jumper last year as well. The adults often lay eggs near the silken retreats of spiders, then the larvae seek out the spider when it returns and enter through the book lungs. The brown stuff near the pupa is probably expectorant from the larvae...since it's a bad idea to defecate inside the host and possibly poison it.

 

[Black Widow88]

Textbook Acroceridae, the small headed flies. I had a friend rear one out of a jumper last year as well. The adults often lay eggs near the silken retreats of spiders, then the larvae seek out the spider when it returns and enter through the book lungs. The brown stuff near the pupa is probably expectorant from the larvae...since it's a bad idea to defecate inside the host and possibly poison it.

WOW! That is amazing! I shall definitely research these further. But not right now as it's late. But thank you for the info.

Black Widow88

 

[JohnxII]

Thanks everyone! Just did a little more digging on information on "small-headed fly" or "balloon fly". Since all acroceridae are parasitoids to spiders (many of which are jumpers), adults are vulnerable to the spiders' attacks, despite on the swiftness of their flying abilities; hence the much smaller larva which are almost invisible to the spiders are up for the job for active seeking and infiltration. Apparently, some of the species' males produce a silken balloon for the female to "play" with when they mate, hence the other common name "balloon fly".

And yes the turd was produced by the larvae before pupation.

Thanks again!

 

[Black Widow88]

They have sex toys in the insect world?!

Black Widow88

 

[Widowman10]

They have sex toys in the insect world?!

that was funny i never knew that about the little silken balloon, that's cool!

 

[lucanidae]

I've never heard of Acroceridae referred to as balloon flies, that name and the behavior you mentioned are characteristic of Empididae. Can you link me to the info saying it for Acroceridae?

 

[Black Widow88]

Well are the 2 families related or something? *Looks the 2 up*

EDIT: I found this on Bugguide. This is the info about Rhamphomyia longicauda ( Empididae ). Said nothing about producing silk balloons.

Adult females congregate in a swarm above vegetation near water around sunset, and inflate abdominal sacs in an attempt to fool males into thinking the swollen abdomens are full of ripe eggs. The hairy legs are held alongside the abdomen in flight, supposedly to accentuate abdominal size. Males hunt small insects and bring the dead prey as "nuptial gifts" to females in exchange for a chance to mate. Males prefer to mate with the fattest and hairiest females, but the cost of being hairy is an increased chance of being caught in spider webs.

Adults are very common in appropriate habitat in southern Ontario. If approached quickly, they fly a short distance to another leaf; if approached slowly, they often walk to the far edge of the leaf they're on, then onto its underside.

Black Widow88

 

[lucanidae]

Google search ' Empididae nupital gift silk ' and you will find all the information about why Empididae are called balloon flies and the wacky things they do for courtship with silk.

 

[Galapoheros]

I'm glad I took a look at this thread finally. The life cycle is what is interesting to me. Ha, are the females so bored that they have to play with a balloon? Hmm, maybe I'll try that. Nice pics!

 

[Black Widow88]

Google search ' Empididae nupital gift silk ' and you will find all the information about why Empididae are called balloon flies and the wacky things they do for courtship with silk.

Will do! Got to get some sleep though. First thing in the morning.

Black Widow88

 

[JohnxII]

I've never heard of Acroceridae referred to as balloon flies, that name and the behavior you mentioned are characteristic of Empididae. Can you link me to the info saying it for Acroceridae?

I guess not a lot of sources refer to Acroceridae as balloon flies... here are a couple links from Britannica:
http://www.britannica.com/eb/article-9012020/balloon-fly
http://www.britannica.com/eb/article-39853/dipteran

And I couldn't relocate the Chinese pages I read about the silken balloons. But I remember it saying small-headed flies (or hunchback flies) are closely related to dancing flies and dagger flies. So it wouldn't surprise me if some of the species have similar mating rituals. To add to the confusion I've read about "balloon flies" were named because of their blown up thorax/abdomen, ability to "blow" a silken "balloon", mating behaviour of some females inflating their abdomen 3-4 times to attract males, but not referring to the actual family or genus - just the common name.

But then of course these aren't official so don't take it from me

 

[Black Widow88]

The one that inflates it's abdomen to attract males is R. longicauda. Says so on a PDF file. The link to it was on the article on Bugguide. I have it but not the link to it. I saved a copy for reference.

I'm a genius! But you can't attach PDF's on here unless it's in a zip. file and I didn't download this one. So I have no clue.

Black Widow88