102 GENUS TENTHREDOPSIS. 



Genus TENTHREDOPSIS. 



Tenthredopsis, Costa, Fauna di Napoli, 98 (1861). 



Tenthredo, Auct. 



Perineum, Thorns., Andre, in part. 



Wings : lanceolate cellule with a very short perpendicular nervure ; 

 accessory nervure in posterior wing appendiculated. In the male the 

 transverse nervures in the posterior wings are usually situated along 

 the outer edge of the wing, all being united together with the accessory 

 nervure, so that thus there are no middle cellules. This arrangement, 

 however, is not always constant, the transverse cubital especially being 

 seldom out of its normal position in the centre of the cellule. 



Antenna long, filiform, the third and fourth joints subequal. 



Clypeus truncated at the apex, seldom incised. 



The mandibles are weak, with only one short subapical tooth. The 

 body is longish, smooth, shining, impunctate, except very rarely on the 

 pleurse. On the thorax the scutellum and post-scutellum are always 

 white. The blotch is never present. 



The species of Tenthredopsis are very similarly 

 marked; the ground colour differs in being black or 

 yellow ; but whatever it may be there are (so far as I 

 know) some white markings on the mesonotum, and 

 the stigma is either of two colours, white at the apex, 

 black or fuscous at the base, or entirely white. "When 

 the ground colour is black the abdomen has, as a rule, 

 the apex, or the middle, marked with red ; the general 

 colour of the legs being also red. All the species are 

 very variable in coloration ; so variable, indeed, that by 

 Klug and Hartig they were all regarded as varieties of 

 one species which the former author named instabilis. 



The separation of the species is difficult owing to 

 their great uniformity in form and sculpture, and the 

 consequent difficulty of finding structural characters of 

 any importance which can be used in specific discrimi- 

 nation. In the form of the saw we have an excellent 

 character for separating the females, but it is difficult 

 of examination and fails us with the males. Much 

 remains to be done in the way of assigning the males 

 to their proper partners; while we are completely 

 ignorant of the earlier stages of all the species. 



I do not know if the species of Tenthredopsis occur 

 beyond the European subregion of the Paleearctic 

 region. 



