188 PROTECTION AGAINST INSECTS. 



2. Sphegidae (Fossorial 



Imacfos with a large head and three ocelli. Antennae slender 

 and moderately long. Fore wings flat and without folds, with 

 1 4 cubital cells. Legs with smooth femora and simple 

 trochanters. Tibiae and tarsi fossorial, and furnished with 

 strong hairs and spines. 



Abdomen stalked, generally with seven free segments, and 

 always terminating in the ? with a sting. 



The larvae and pupae somewhat resemble the perfect insects, 

 but have no legs. 



These insects appear in summer, living in pairs and building 

 their nests in sandy earth, in rotten wood, cracks in walls, 

 etc. They attack plant-lice, larvae, beetles, grasshoppers, and 

 spiders, wound them with their stings, and convey the disabled 

 insects to their nests in order to lay their eggs on them. 

 Some species close up the cells in their nests, and the larvae 

 on emerging from the eggs feed upon the captives. Other 

 Sphegidae feed their young with fresh material. Whilst these 

 insects are hunting their prey, they carefully close their nests 

 with particles of sand or splinters of wood. 



The following are common : Ammophila sabulosa, L., and 

 Pompilus viaticus, Latr. ; both species live in sunny places in 

 sandy localities. 



3. Vespidae (Wasps). 



Imayos moderately slender, almost free from hairs, black or 

 brown with yellowish zones, with ocelli. 



Antennae approximate at the base, elbowed, and with 12 13 

 joints, thickened at the apex. 



Fore wings folded longitudinally when at rest, with a radial 

 cell reaching to the end of the wing, and 2 3 cubical cells. 



Legs simple, without prominent hairs or spurs. 



Abdomen stalked, furnished with a sting in the ? . 



The larvae are white or yellowish, with brown heads, soft 

 and legless. 



The species which form this family live either, socially, or 

 are solitary. 



Those which are most useful, from a forest point of view, 

 are social wasps, consisting of three classes: $ (drones), ? , 



