XXV 



INSECT A : HYMENOPTERA 



397 



and Solitary. No less than sixteen species of these wasps are 

 British, though they seem but little known except to specialists. 

 The British species are all alike in having a narrow black body 

 with yellow bands on it and all have bifid claws on the tarsi. 



The genus Eumenes includes several solitary wasps, of 

 which the only British species is Eumenes coarctata. This 

 wasp forms little clay vase-shaped nests attached to twigs 

 of heath or some other shrubby plant (Fig. 305, c). The 

 insect itself is easy to distinguish from all other British 

 solitary wasps by its very narrow " petiole " or waist-segment 

 (Fig. 305, 7). It has stripes and spots of wasp-yellow colour 

 on its otherwise black body. 



The nest figured was made of coarse yellow sand, and 

 was rough and granular outside, but was lined inside with 

 smooth white silk, and a silken partition ran across the cell, 

 separating off a small irregular space at one side, in which 

 a certain amount of dark-coloured debris is to be seen 

 (Fig. 305, , d), apparently the excreta of the larva. 



All our other British 

 solitary wasps belong to 

 the genus Odynerus. They 

 have a wider petiole than 

 Eumenes, and all live in 

 holes in walls, in wood- 

 work, or in the ground. 

 Odynerus parietum is a 

 common British species with 

 very variable black and 

 yellow colouring, sufficiently 

 wasp-like to have gained for 

 it the name of the Wall 

 Wasp (Fig. 306). Odynerus 

 spinipes is also fairly com- 

 mon ; it is rather larger 

 than 0. parietum and has 

 narrower, yellow, transverse 

 bands on the body ; also on the femur of each of the second 

 pair of legs are characteristic little projecting teeth. ,This 

 species makes its nest in banks, protecting the mouth of it 

 with a small projecting tube of earth, beautifully made but 

 very fragile. All these solitary wasps provide for their young 



FIG. 306. The Wall Wasp 

 ( Odynerus parietum}. 



