158 GENUS DOLERUS. 



have been identified they do not differ in any essential 

 points from those of the Tenthredinides. All the 

 species that have been discovered feed either on 

 grasses (Festuca, &c.) or on Juncus. In colour they 

 are greenish, or dark coloured on back and upper part 

 of the sides, the lower part being white. So far as is 

 known they do not spin cocoons, but form cells in the 

 earth to pass the period of transition. 



They are of wide distribution in the Palasarctic 

 region, they are also found in Northern China, and are 

 not uncommon in the Nearctic region. Nearly sixty 

 European species have been described, as well as 

 seventeen North American. 



Leach formed the yellow-banded species into a 

 distinct genus Dosytheus, which he separated from 

 Dolerus by the species (according to him) having the 

 third antennal joint longer than the fourth, these joints 

 being said to be equal with the other genus. That 

 peculiarity, however, is worthless, as is also the colour, 

 which was used by Stephens as a means of generic 

 distinction. The sub-tribe thus contains only one 

 genus.* It is most nearly related to the Tenthre- 

 dinides, but differs in the alar neuration and body 

 form, which is very uniform. Most of the species 

 have the head and thorax punctured and covered with 

 longish hair, this latter being the case with the apical 

 abdominal segments and the belly. The last (ninth) 

 abdominal segment is more developed on the dorsal 

 side than in the Tenthredinides. 



The yellow-banded species are not difficult to 

 identify, but great difficulty is experienced in deter- 

 mining the black-bodied ones, and I am not at all 

 satisfied that I have succeeded in describing our 

 species in a clear manner. It is very difficult to find 

 good specific characters that do not vary ; and another 

 difficult task is to assign the males to their proper 

 partners. The best characters appear to be afforded 



* As regards Pelmatopus (placed by Hartig as a sub-genus of Dolerus') 

 see infra. 



