1918.] 123 



fourth abdominal segments or on one of these. Quite the opposite to 

 the first mentioned specimens, in others the abdomen becomes actually 

 more hairy than in normal ones, though in some cases the greater 

 hairiness is only apparent and due to tlie decumbency and pale colour of 

 the hairs on the third and following segments. Some of these examples 

 have much black hair on the clypeus, while in others the clothing of this 

 part is normal. It is doubtful whether in nearly 50 cS bees examined 

 any one of these Avould be passed over as normal, were the Stylops or its 

 puparium unseen, though some closely approach the normal condition. 



In the females the tibial scopa is always more or less deficient, 

 usually conspicuousl}^ so, in rare cases only very slightly so, and some- 

 times all the hairs of which it is composed are of a tawny colour, the 

 black or dark fuscous ones of the normal scopa being entirely changed. 

 Only rarely is the characteristic silvery hair of the pollen -brush beneath 

 retained, <?. r/. in three out of twent3'-four examples casually examined. 

 The clothing of the abdomen often appears denser and more conspicuous 

 than in healtliy examples, the hairs being pale throughout and more 

 depressed. Some examples — about one in ten of those examined — 

 correspond in appearance to those males I have described above, as most 

 altered, the abdominal pubescence being veiy deficient. One of these 

 has the scopa greatly degenerated and fulvous in colour throughout, the 

 abdomen being much distorted also, while another has the seopae hardly 

 at all deficient ! Both these examples have borne S Stylops. In stylo- 

 pized females the inflation or abnormal convexity of the abdomen is 

 usually conspicuous. 



Stylopized examples of A. trimmerana are numerous in many 

 localities and I have, in drawing up the above notes, examined about 

 80 examples in various collections and from many localities. 



4. A. wilkella K. — The result of the stylopization varies greatly in 

 different individuals, but in this species there is one feature which is 

 almost constant, so far as I can gather from the examination of about 

 50 examples. 



As in other species the greatest changes are usually the result of 

 the 6 parasite. In the most extreme forms the abdomen becomes more 

 shining and the chitinous integument looks thinner than in normal 

 specimens, the punctures being also less close. The pubescent bands of 

 the abdomen may approach or be identical in appearance with those 

 of the very closely allied species, A. ovatula {afzeliella). The hind 

 tibiae of the $ , the yellow colom- of which is so constant in healthy 



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