Diptera.info

Posted by ChrisR on 19-06-2006 10:56

I'd just like to add that I have always held that identifying ANY ichneumonoid from a photo is *very* speculative unless there is absolutely no doubt. I just looked at the photo here and thought there are too many species that look similar and without a clear view of the wing venation, face, gaster and propodeum it isn't worth offering a name. :(

Can the people who responded with names say exactly why they think it is that species? B)

Posted by cthirion on 20-06-2006 12:24

From Valemberg , french ichneumonologist (Lille)!

Non, je ne le pense pas.
Tout d'abord aucun ?l?ment structural sp?cifiquement indispensable ne peut ?tre appr?ci? sur cette vue; nous n'avons d'ailleurs aucune id?e de la taille ( probablement autour de 10-12 mm, pas plus) . Malgr? le p?tiole invisible je pense ? un platylabien car on peut distinguer :
1) habitus tr?s d?li? du Platylabini : pattes gr?les et allong?es, flagellum gr?le avec macule blanche r?duite et situ?e dans la moiti? post?rieure
2) les segments ant?rieurs de l'abdomen sont margin?s apicalement
3) dessous des coxae macul? de blanc (voir notamment les procoxae)
4) orbites externes enti?rement blanches (pratiquement tous les platylabiens ont les temps ainsi macul?es ext?rieurement)
5) alitronc tr?s macul? de blanc (lignes hum?rales enti?rement notamment)
et surtout la t?te tr?s ?troite antero-post?rieurement avec les tempes particuli?rement fuyantes; scapes tr?s courts). Tout ceci nous ?loigne des coelichneumon et nous rapproche des platylabiens.
Pour moi cette vue peu appr?ciable nous rapproche du Pristiceros infractorius m?le mais dont les segments ant?rieurs un peu rufescents de l'abdomen sont un peu g?nants; par contre chez cette derni?re esp?ce les segments m?diaires de l'abdomen ont bien la marge post?rieure margin?e de clair comme sur la vue. Les pattes sont celles des platylabiens. Scutellum trop plat pour Hybophorellus; t?te trop ?troite pour Acolobus sp.:)

Posted by Robert Nash on 20-06-2006 13:44

Chris's comment is generally true but this excellent photo depicts an insect identical in all visible respects to our museum specimen determined by both Brock and Aubert. Chthirion is correct :p:p unless we have both been misled by a truly (ad I think impossibly)remarkable mimetic. We (RN JP O'Connor, Dublin) work on Ichneumonidae using a combination of expertly identified specimens and keys, descriptions and monographs (Ulster Museum National Museum of Ireland). Incidentally we only have three specimens all from Scotland. Summary Pristiceros infractorius surely.

Posted by Robert Nash on 20-06-2006 13:58

Info: Gavin Broad's excellent Checklist of British and Irish:p Ichneumonidae (155 pp.) is on

http://www.brc.ac.uk/downloads/Ichneumonidae_checklist.pdf

in this list Pristiceros infractorius is annotated England (not Scotland, Wales Ireland). We are currently working through the taxonomically clean (well identified) material in Ireland to improve the geographic data in Gavin's list.

Posted by Robert Nash on 20-06-2006 14:31

#10

Translation (draft) First of all no specifically essential structural element can be appreciated in this photo: we do not have any idea of the size besides (probably around 10-12 mm, not more).
In spite of the invisible petiole I think of a platylabine because one can distinguish:
1) jizz ? typical of Platylabini: legs thin and lengthened, flagellum with reduced white macula (spots) and located in the posterior half .
2) the anterior segments of the abdomen with apical ?margin?s?

3) lower part of the coxae maculated (spotted) white (see in particular the procoxae)
4) entirely white external orbits (practically all the platylabines have times thus maculated outside)
5)
alitronc (mesothorax) very maculated with white (humeral lines entirely and in particular)

Especially the very narrow (antero-posteriorly) head with the particularly reduced temples (area between ocelli and eye; scapes very short) suggests not Coelichneumon and brings closer us the platylabines
For me this not very appreciable sight brings us closer to male Pristiceros infractorius but the anterior segments of the abdomen being a little rufescents is little awkward; on the other hand at this species has the medial segments of the abdomen have well the posterior margin light as seen. The legs are those of the platylabines. The scutellum is too flat for Hybophorellus; the head too narrow for Acolobus sp.

Note the reliance on shape and proportion and less defined thoracic and head "areas":( than in Diptera and no chaetotaxy to help. Fortunately Townes Genera of the Ichneumonidae benefited from Japanese illustration. Note also Chthirion's mix of diagnostic and diiferential characters. Very well argued case:p and a tough call. Impressive.

Posted by ChrisR on 20-06-2006 15:05

#11

Thanks Robert - very interesting :) I am probably over pesimistic with ichneumons but I like to try and encourage people to key specimens rather than think they will get good identifications from photos, as this isn't possible in most cases (this being one exception) ;)

I have downloaded Gavin's checklist and will keep it handy - there must have been plenty of name changes since the old keys were written.

Posted by Robert Nash on 20-06-2006 16:16

#12

Too right on all (keys pessimism and name changes). Interestingly I saw Jacques Aubert and his collection in Lausanne museum last year. His specimens are on huge pins which have removed most of the thorax.(Everyone be warned. Pins can be too big or too small). Even so Jacques ichs are immensely useful sinc so many characters are impossible to describe.Great list from Gavin. Brave soul.

Posted by Robert Nash on 18-07-2006 16:25

#15

Just received " Matt Riedel confirmed that the ichneumonid in the photo is not a platylabine (Matt has almost completed his revision of Platylabus and knows the tribe better than anybody) and agrees with me that it is probably a male of some species of Cryptini. As to what species, no idea I'm afraid.All the best,Gavin

Dr Gavin Broad
Coordinator of Zoological Data & Research, Biological Records Centre, Centre for Ecology & Hydrology, Monks Wood, Abbots Ripton, Huntingdon PE28 2LS
ENGLAND

Posted by Robert Nash on 18-07-2006 17:21

#17

Camille I agree.Not Cryptini. I posted what I received but perhaps Matt could qualify "probably" and "some".I repeat "excellent photo depicts an insect identical in all visible respects to our museum specimen of P. infractorius determined by both Brock and Aubert". Robert. I'll contact Matt for more argument.

Edited by Robert Nash on 18-07-2006 17:33

Posted by LordV on 19-07-2006 08:00

#20

Just received this from Gavin Broad. "Just in case you are still interested, Matt Riedel confirmed that the ichneumonid in the photo is not a platylabine (Matt has almost completed his revision of Platylabus and knows the tribe better than anybody) and agrees with me that it is probably a male of some species of Cryptini. As to what species, no idea I'm afraid."
More discussion?
Brian V.

Posted by ChrisR on 19-07-2006 12:08

#21

Hmm, considering:
- we can't see clearly any of the most important features used when keying parasitica (propodeum; face; surface texture & carinae on the thorax and gaster) and
- parasitica are notorious for being both subtly variable in colour AND looking very similar and
- Gavin Broad & Matt Reidel both won't even commit to tribe, let alone to genus

... all suggests my pessimism was well founded! ;)

Posted by cthirion on 19-07-2006 18:59

#22

Pessimism was founded............ non,.le realism is founded! ?

?Matt has just re-examined my Coelichneumon, I wonder sometimes if we use the same keys or the same decriptions............ moi and others arrivont not with the same species! ?

?Even Horstmann gives up helping me for this group! ?

?I believe that the difficulties of this group, the dispersed literature...........le makes that much publishes anything believing to control the subject, all that complicates the revision! ?

?But especially, the opinions of those which never published on this group are painful! ?

?For let us ichneumons, one is still at the stage to re-examine the types......... when they are found! ?
?That made several hundreds of species which change name or are red?crites per annum! ?
?To go to throw a glance on TAXAPAD of Yu, you will include/understand, it makes the synthesis of knowledge of this group on a world level! ?B)

Posted by ChrisR on 19-07-2006 23:28

#23

Certainly, finding literature is one of the most serious problems when studying parasitica. Then when you find a key you often find it is 50 years old and has been superceeded by many name changes and additional species - all written-up in individual papers published in different countries, in different languages! :)

Posted by Xespok on 20-07-2006 08:14

#24

That is why all keys should be published on the internet within a wikipedia like project... Publishing keys in written form is quite contraproductive.

The nicest example of the problems associated with the current system is that of the Eastern-Palearctic region, where three very different cultures (Chinese, Japanese, Russian) meet, each with very different language and writing. Also the countries hava relationship far from being friendly, which has restricted communication even further. Furthermore, the use of English is far from general in any of these countries.

Posted by cthirion on 20-07-2006 12:05

#25

he problem is still much more serious than you think it! ?

?Not badly of species for lack of communication, described in the Eastern European countries are already described and put gradually in synonymy! ?

?To open the wikipedia................with all those which think that to make a key...........des recent work is simple coming from Bulgaria introduced a crowd of species which also should be downgraded! ?
?Moreover all reliable European specialists from go away! ?
?It is simpler to go to describe faunas of the Latin America, of Australia, or India or North Africa that of the probl?mes of European fauna and one has less of literature to compare and especially less contradictors! ?