126 



WASPS 



[CH. V 



dragonfly very powerful on the wing but uses its legs 

 very seldom for walking: the wasp flies strongly and 

 can travel at a fair pace by walking or running. The 

 mechanism of the wings is such that the anterior and 

 posterior wings of the same side move as one. At about 

 half-way along the anterior border of the hind-wing is a 

 row of hooks (4 Fig. 21) (thirty- two in number in the 

 females, but fewer, generally about twenty, in the males), 



Fig. 21. Hind-wing of a wasp. Magnified. 



Tuft of strong hairs. 2. Short hairs. 3. Long hairs, all of 

 which project forwards under the front wing. 4. Hooks for 

 fastening anterior edge of hind-wing to posterior edge of front wing 

 only a few hooks are represented. 5. Short hairs. 



Fig. 22. Part 4 of Fig. 21 to show the difference between the shapes 

 of the proximal (h) and of the distal (/*') hooks. 



with slightly upturned points. On the posterior edge of 

 the front wing is a crest forming a ledge, beneath which 

 the ends of the hooks catch when, and as, the wings are 

 extended for flight. The hooks nearest to the attachment 



