Diptera.info

Posted by Michael Becker on 29-06-2009 20:37

Hello,

this ~9mm larvae is from last weekend from a forest near the river Ahr (western germany). It feeded the leaves of some small caryophyllaceae, perhaps Myosoton aquaticum.

Can perhaps the family or the genus be identified?

Thanks,
Michael

Edited by Michael Becker on 01-07-2009 20:47

Posted by John Bratton on 30-06-2009 17:28

I think it is a type of cranefly, no longer Tipulidae, four British species in a family of their own, two terrestrial and two aquatic, one of the aquatics being Triogma trisulca. Is that enough clues? If not, I'll try to come up with a name tomorrow after I've been home (in the public library at the moment).

John Bratton

Posted by Michael Becker on 30-06-2009 21:25

Hello John,

thank you for your answer. I don't have any literature here, but I think you spoke of the Cylindrotomidae with the four genera Cylindrotoma, Diogma, Phalacrocera and Triogma. Two of them are aquatic, so two remain for my larva, but I don't know wich.

The larva now lives in a box in my kitchen. Do you know if there is anything special to look for when growing it? Up to this point it readily feeds on the plant I brought with me. Are these species more polyphagous or monophagous?

Greetings,
Michael

Posted by John Bratton on 01-07-2009 11:17

Yes, Cylindrotomidae is the family I couldn't remember. I think yours is Cylindrotoma distinctissima, unless you have more species in Germany. We have only the one species in each genus. Brindle's 1967 key goes:

Dorsal processes toothed on anterior convex side ....
Triogma and Diogma

Dorsal processes not toothed ... Phalacrocera and Cylindrotoma

So they've all got big soft points along their back, but Triogma and Diogma have additional little points along the leading edge of the big points.

It says for C. distinctissima: Larvae free-living on the leaves of Caltha, Viola, Stellaria, Anemone, Petasites and Chrysosplenium, in marshy woodland. Light green, dark dorsally. Posterior spiracles dorsal, no obvious spiracular disc. Length 20 mm. Pupae hang head downward from plants, the cast larval skin retained at base of pupa.

The other terrestrial one, Diogma, is found in mosses in limestone woodland. Anal segment with posterior spiracles inside a cavity.

Best wishes
John Bratton

Posted by Michael Becker on 01-07-2009 20:46

Hello John,

again thank you for your answer.

I think yours is Cylindrotoma distinctissima, unless you have more species in Germany.

According to the Fauna Europaea there are only two species in Europe: distincitissima and nigriventris, and the latter is east-palearctic (Finland, Russia) and absent in middle Europe.

It says for C. distinctissima: Larvae free-living on the leaves of Caltha, Viola, Stellaria, Anemone, Petasites and Chrysosplenium, in marshy woodland.

It could have been a Stellaria species, on which I found it. Myosoton is closely related. Now in the box in the kitchen I tried Stellaria media from my garden and the larva eats it.

Light green, dark dorsally. Posterior spiracles dorsal, no obvious spiracular disc. Length 20 mm.

Ok, the larvae grows and is now more than a centimeter. Color is ok. The thing with the spiracular disks I don't understand.

Pupae hang head downward from plants, the cast larval skin retained at base of pupa.

If I succeed in growing it, I will take photos of the pupa and post it and the adult to the gallery too.

Greetings,
Michael