VIII 



BOMB US LATREILLELLUS 18 



o 



from the other by the following characters : the slightly 

 shorter cheeks of latreillellus ; the shorter coat of latreil- 

 lellus, most noticeable on the ist segment of the abdomen, 

 especially if there are yellow hairs there ; the narrow 

 yellowish or brownish fringe on the edge of the 2nd seg- 

 ment, almost always present in latreillellus, but seldom in 

 ruderatus ; and lastly, a very conspicuous distinguishing 

 character which, although it is not mentioned by Smith 

 or Saunders, holds good in every specimen I have 

 examined. This is in the relative widths of the yellow 

 bands on the thorax. In latreillellus the band at the back 

 of the thorax is much narrower than the band at the front, but 

 in ruderatus the bands, measured across the middle, are 

 approximately of equal width. 



Worker. Large; length 12-18 mm. 



Resembles the queen, but the yellow band on the 

 back of the thorax is sometimes absent, and in small 

 specimens there is generally no trace of yellow on the 

 ist segment. 



Male. Rather large; length 15-16 mm., expanse 

 28-31 mm. Abdomen rather elongate. 



Pale yellow with a greenish or brownish tinge, with the 

 exception of the following black markings. The head 

 black, except on the top and in the middle of the face. 

 A black band across the thorax between the wings. A black 

 band across the 2nd segment of the abdomen, and another, 

 generally narrower, across the 3rd segment ; these bands are 

 separated by a narrow band of greenish-white on the 

 edge of the 2nd segment ; 6th segment black in the 

 middle, 7th segment black. This colouring resembles 

 that of Psithyrus campestris male, the description of which 

 should be consulted. 



In light specimens the black bands on the 2nd and 

 3rd segments are reduced or absent, the 6th segment is 

 entirely yellow, and the 7th partly so ; in the lightest 

 specimens, however, there are always some black hairs on 

 the 2nd segment, chiefly at the sides, although they are 



