Pemphredon morio?

[JRsbugs]

Hello all

I have keyed this wasp to Pemphredon morio. The wing venation is correct, short stalk of abdomen and there is a visible 'horn' between the antennae!

This is a rare and scarce species, Notable B unless that has changed.

insect - hymenopteran - Sock Searcher

Found in my garden on 14th July. It thought it was ~10mm, bigger than the 8mm stated in the keys but it didn't hang around long, I got three shots.

On the Essex Field Club site it states:

This species (as both Pemphredon morio and P. clypealis) is a scarce, but widespread species recorded from about 25 vice-counties from E. Cornwall to E. Kent and north to S. Lancashire and N.E. Yorkshire, with about 35 post-1970 records

Species Account for Pemphredon morio

I don't think it can be anything else?

Janet

[Roger Morris]

Sorry Janet

It is not even a Sphecid - it is a bee - a long while since I did much with these so I'm not going to put a name to it. Sphecids don't have hairs. Pemphredon has a definite petiole.

Roger Morris

[JRsbugs]

Originally Posted by Roger Morris

Sorry Janet

It is not even a Sphecid - it is a bee - a long while since I did much with these so I'm not going to put a name to it. Sphecids don't have hairs. Pemphredon has a definite petiole.

Roger Morris

Hi Roger, gee, I spent so long trying to get it right too!

I thought the wing venation matched that of Pemphredon as outlined in "Solitary Wasps" by Yeo & Corbet P. 43 fig. V1 11 where vein 10/11 joins cell SM2 before the middle.

That took me to #10 where Pemphredon morio was the one of two in the couplet which apparently fits. "stalk of abdomen not more than 1/3 as long as swollen part of 1st segment; with a horn between the antennae (V1.9)"

The specimen on bold systems certainly looks hairy to me, you can use the magnifier to see it better.

BOLD Systems - Taxonomy Browser

A photo which shows it to be hairy assuming it's correct..

Natuurpunt Gent - Natuurfotogalerij

One on Nature Conservation Imaging site..

http://www.natureconservationimaging...edon-morio.jpg

Another on this French site which shows hairs on both thorax and abdomen.. the wing venation matches too.

Pemphredon morio - www.galerie-insecte.org

It didn't occur to me that it might not be a wasp, if it is a bee I'm really struggling to know which it is.

[JRsbugs]

I've marked out the details as in the keys.. the horn is better seen in the other photo I lightened.

Anyone else have anything to say about it?

[eucera]

In my experience, Pemphredon species are really quite shiny. The pic shows an insect with extremely dense punctation on the head, thorax and abdomen. At a casual, and rather blurry glance, it looks much more like a male Myrmosa atra than a Pemphredon to me. It also looks to have 3 submarginals

[JRsbugs]

Originally Posted by eucera

In my experience, Pemphredon species are really quite shiny. The pic shows an insect with extremely dense punctation on the head, thorax and abdomen. At a casual, and rather blurry glance, it looks much more like a male Myrmosa atra than a Pemphredon to me. It also looks to have 3 submarginals

Thanks Stuart, that at first glance looks possible. Of course I'm doing my head in trying to find evidence!

Firstly, it does in a way look to have three submarginal cells, but the vein which cuts across the first large cell should perhaps come from the stigma? There is a vein which doesn't do that, however I can maybe see a whitish vein but not sure about that as I would think it should be black the same as the other veins?

The specimens of Myrmosa atra on bold systems are not good, with magnifying still not good!

BOLD Systems - Taxonomy Browser

The back view certainly shows similarities, although the wings do appear to be much shorter than they show on mine. By clicking on the second photo on bold systems brings up more side views, again the wings appear to be well short of the abdomen but it's still a difficult thing to assess.

If this drawing of Myrmosa atra wing venation is correct, then the whitish 'vein' isn't a vein but the other vein which cuts from the corner of cell SM2 and cell 2 does fit with that. I wasn't sure about that vein as I have found there is an extra vein cutting into a cell on some individuals and not on others in bees at least.

N.IT. Foto - Myrmosa atra P0914

Now I'm getting really confused! On Bibio.cz they have it in the family Mutillidae, yet it's in Tiphiidae on delta-intkey!

BioLib - Mutillidae (velvet ants) - Image - Myrmosa atra

British Insects: Hymenoptera Families - Tiphiidae

The wing venation matches except for that extra vein I mentioned in the first cell, it goes all the way to the top.

There is still the question of the horn between the antennae. I'm sure it has one. The notes in the keys state that:

In Pemphredon the surface sculpture varies much within the species.

[Matt Smith]

Get out Yeo and Corbet - Solitary wasps. It has 3 submarginals and keys happily and easily on Key IV (Solitary Wasps with 3 submarginal cells and black or red markings) couplet 3 to Myrmosa atra. Picture IV.2 shows an identical wing veination to your insect.

[JRsbugs]

Originally Posted by Matt Smith

Get out Yeo and Corbet - Solitary wasps. It has 3 submarginals and keys happily and easily on Key IV (Solitary Wasps with 3 submarginal cells and black or red markings) couplet 3 to Myrmosa atra. Picture IV.2 shows an identical wing veination to your insect.

Yes!!!

I meant to check the keys but got lost.

The wing venation fits perfectly!

[JRsbugs]

I found Myrmosa atra is a parasite of "Crabro peltarius, Crossocerus palmipes, Diodontus minutus and uniglumis especially Oxybelus."

Myrmosa atra

I have Crabro peltarius and Oxybelus uniglumis that I know of!

[Roger Morris]

I stand corrected re my mis-ID to bees - I was wracking my brain as to where I'd seen this and would go with male Myrmosa atra - not a thing one sees terribly often, but I admit to my mistake. I've checked the specimens in my collection and they correspond to the photo. As I said, some aeons since I did much with aculeates - but frankly that is no excuse - for mistaking Scolioidea for a bee.

I have specimens of P. morio, P. lethifer, P. inorata and P. lugubris in my collection and none of these looks like the photo. They are relatively unpunctures, shiny and lack hairs. The protuberance between the antennae in P. morio is 'relatively' obvious; also the petiole is very distinct - which I don't think can be said of M. atra.

I have also checked my specimens of M. atra and can also advise that there is no protuberance between the antennae - so if there is genuinely one in the photo (which I remain unconvinced) then this cannot be M. atra (unless my specimens (that have been checked by well-respected Hymenopterists) are wrong.

As to possible hosts, it is worth bearing in mind that female M. atra are wingless - so the males may disperse quite widely. Looking at my (rather old) data I've only taken females in pitfall traps - and males a couple of times - they occasionally visit flowers.

RM