ID confirmation and behaviour help - please!

[acherontia]

I think this is Mellinus arvensis?

There were quite a few mating and afterwards the females were killing (I think ) flies. Not hoverflies, that were also plentiful and which my book says they mostly use.

I can't seem to find the info on what stage the females take the flies into the burrow. Do they lay into the corpse (if it is dead) or take the fly to the grubs - or both?

It was fascinating.












Acher

[JRsbugs]

It is Mellinus arvensis, one I have in my garden. I got them mating last year, the female immediately started to catch flies. They usually take Pollenia species, but they will take other flies.

I think the fly is placed in the pre-prepared nest then an egg is laid, the fly providing the larva with enough food to grow. Notice how the female sticks them through the tongue, gruesome!

[acherontia]

Thankyou, JRsbugs

I'm presuming the fly is dead then? I seem to remember some species of invertebrates use living but paralised food for their larvae.
Interesting they just lay one egg for each fly.

The insect world is indeed gruesome!

Ta again,

Acher

[JRsbugs]

I would assume the fly is dead, they hang onto the tongue for some time so I imagine the fly dies of shock if nothing else or they would be severely traumatised! I have some photos of one being pincered, not a pretty sight.

Considering the size of the wasp I think a whole fly per offspring would be necessary.

[Matt Smith]

The flies are not dead - merely paralysed. If they were dead they would rot. The wasp larvae like their meat very fresh, so the fly gets eaten alive. Several flies are placed in each cell.

The "tounge grip" is just the way this species carries its prey - Oxybelus species carry their fly victims back to the nest impaled on their sting.

[acherontia]

Ahhh - I thought that a bit of living meat might last a little better for the larvae.

Thanks again - both of you

Acher