Walter Ritchie 



301 



than on the upper, and is somewhat variable in colour, so thai the insect appears to 

 vary from quite a lighter grey to an ochreous-yellow; head large, antennae tapering 

 with the apical joints not ringed with white; thorax slightly transverse, coarsely and 

 rugosely punctured, with a central line and a tubercle on each side of it which are 

 usually covered with pubescence; scutellum large, semicircular, elytra broad, with 

 well marked shoulders, gradually narrowed at apex, which terminate at suture in a 

 short blunt spine, very coarsely and deeply punctured, with a transverse patch of 

 closer pubescence on each about the middle; legs short and stout, pubescent, extreme 

 apex of femora usually black. L. 20-28 mm. 



Fig. 1. The large poplar Longhorn, Saperda carcliarias L. Male. Tarsal claws of a foreleg 

 are shown on the left (both greatly magnified). 



Male (Fig. 1) with antennae a little longer than the body, and the elytra more 

 narrowed behind; female (Fig. 2) with the antennae a little shorter than the body, 

 the elytra slightly narrowed behind and the fifth ventral segment of the abdomen with 

 a line channel towards base. 



Sexual Differentiation in S. carcharias. 



From my observations made in handling a very large number of 

 individuals of both sexes, I find there is no difficulty in differentiating 

 them, for not only are they different in size but they also differ in their 

 general form; there is the difference also in the tarsal claws to which 

 I have already referred. 



Ann. Biol, vii 20 



