4 THE HESSIAN FLY IN GREAT BRITAIN. 



The ends of the tai'si and fore tibise are generally darker than the 

 other parts. 



Wings pink at the roots, and clothed with black hairs ; the 

 second longitudinal vein runs nearly straight until near its 

 extremity, when it curves slightly down and reaches the border of 

 the wing a little above (or before) the apex. The third longi- 

 tudinal vein gives off its descending branch in the usual way, 

 which reaches the hind margin of the wing at a point exactly 

 opposite the termination of the first longitudinal vein. 



Male. — The male insect differs from the female by being 

 about one-third shorter, and much more slender. The antennse 

 have the same number of joints (seventeen), are pedunculated, 

 and proportionally longer, being about two-thirds of the length 

 of the body. The joints are ovoid in shape, becoming nearly 

 globular towards the end. The terminal joint is not longer than 

 the others, as in the female. The stalks are about half as long 

 as the joints. The verticellar bristles are much longer than those 

 in the female, and white in colour. The tuft of hairs on the end 

 of the scutellum is also white. 



The abdomen is almost black, with a pink extremitj', but is 

 really marked in the same way as the female, with large square 

 black spots, only being very slender they coalesce ; thus the two 

 lateral rows cover the dorsum, only leaving a narrow pink line 



/ 

 Male genital orp;ans from above. 



down the centre, which is sometimes indistinct, and a pale streak 

 across the edge of each segment. The spots on the ventral aspect 

 hide the undei'lying colour altogether. The last joint of the 

 abdomen is of a pale pink colour, and is provided with a pair of 

 claspers or forceps of a brown colour, between which are seated 



