362 



HYMENOPTERA ACULEATA. 



difficult to appreciate. There are several species which, as a 

 rule, are quite easy to recognize, but of which rare varieties 

 occur quite unlike the typical form. The most reliable charac- 

 ter is the form of the $ genital armature ; this will always 

 guide one rightly, but in the absence of the S it is some- 

 times impossible to say for certain what a ? or $ is. The 

 structural characters in these latter are to be looked for in 

 the shape of the face, and especially the length of the 

 cheeks and of the tongue, and the form of the intermediate 

 and posterior metatarsi. 



The genus Bovihus is very widely distributed, but is 

 commonest in temperate regions ; according to Smith it is 

 absent in Central and South Africa, Madagascar, Australia, 

 and New Zealand, but lately it has been introduced into 

 the two last-named colonies. Fifteen species occur in our 

 islands, which may be tabulated thus : — 



(6) 1. Thorax clothed with yellow or brown- 

 ish-yellow haira without indication 

 of a darker transverse band. 



(5) 2. Pubescence of the abdomen above in 

 both sexes entirely pale, shorter, and 

 more regular, second segment with 

 a basal band of more orange-brown 

 coloured hairs ; this colour is partly 

 due to the hairs being more erect, 

 and therefore seen at a different 

 angle ; c? '"'^^^ the antennal joints 

 scarcely rounded beneath, and 

 sagittffl of armature hamate at the 



(4) 



(3) 4. 



(2) 5. 



apex. 



(J, third joint of the antennas con- 

 siderably longer than the fourth ; 

 pubescence of underside usually 

 black in both sexes, but if pale, then 

 with the tibiae clothed with black 

 hairs . . . • 



(J, third and fourth joints of the 

 antennaa subequal, pubescence of 

 underside and tibiae pale in both 



Pubescence of abdomen usually with 

 black hairs intermixed, longer, un- 

 even, and somewhat ragged, all the 



Smithianus. 



