Antennae waving in Weevils

[poschiavanus]

I've just been looking at a mating pair of broad-snouted weevils (no photos, no ID yet) and noticed that from time to time the male held his antennae out from the body and waved them about rapidly (5-10 times a second). From time to time he also did this with one or other antenna.

I presume that this is some kind of mating display, but wondered if anyone else had noted such behaviour.

[The Woodman]

Never seen that happen. Could the male have been scenting pheromones from the female or was it just an expression of orgasmic joy?

[poschiavanus]

Thought I'd have a go at capturing images via the USB microscope, so here's one each of the male & female.



Any pointers as to what they are gratefully received.

[Jason Green]

Afternoon Martin,

Yes, as the Woodman says I'd imagine it's reproduction-related, or scent-based. I must say I've never actually noticed it myself either! It doesn't narrow it down by much, but I'd say it's from the Curculionidae family.

Take care,

Jason

PS, what USB microscope is that you've used?

[Rossco]

Probably some form of courtship related behaviour, as these things often are in adult insects. As for the weevil in question, it looks like a Phyllobius spp.

[Jason Green]

I think it looks like Phyllobius too - Martin, can you get a shot of the elytral scales and a tibia?

With a little minor interpretation leading to a tentative ID, from what I can see it's Phyllobius pomaceus.

[poschiavanus]

Thanks Rossco, pretty sure these are Phyllobius the antennae are clearly inserted on top of the head. I'll take a closer look at the femora to see if they are toothed.

Trevor Pendleton has an excellent page on these weevils at Eakring Birds.

Unfortunately they're very active at the moment: I'll have to put them in the fridge in the hope of slowing them down.

The USB microscope was from Maplin around November time.

[Jason Green]

Yes, your femora are toothed to my eyes - middle leg, image two.

Is the USB by Veho?