155 



1913.] 



— Abdomen witli no red markings, only black and yellow 6. 



6 Hind femora always black or streaked with black "• 



- Hind femora (and practically the whole of all the legs) yellow. Abdomen 



with broad yellow fascia much dilated laterally, on all the 

 segments except the basal. (Tempera not sharply margined behind ! ) 

 Pronotimi widely, tegiiloj, and two basal joints of antemiEE yellow.... 



A. flavipes ? . 



7 Some segments of abdomen entirely black ; others yellow, or banded more 



or less broadly with yellow, these bands being nearly equally broad 

 throughout (not more so laterally than in the middle!). Tegulaj, or 

 mesopleuraj, or ventral plates of abdomen, or all these, often black 

 entirely 



— Variable in colour, but the abdominal fasciae are (n.b.) always much dilated 

 laterally, so that the sides of the insect are yellower than its back. 

 (Generally each segment is very narrowly edged with yellow above, 

 while the sides and belly show more yellow than black). The teguloe* 

 and mesoplevu-se are ahvays marked with yellow. The seixtellum and 

 the two basal joints of the antennae may be either black or yellow. (If 

 both scutellum and antenna are entirely black it is the var. 7iitidior of 

 Knw.)r-An extremely common species everywhere ....arcwatus, Forst. 



8 Upper wings distinctly (though it may be slightly) infuscated in certain 

 areas, and clear in others. Head and thorax pretty strongly punctured, 

 and either dull or only slightly shining 9' 



— Wino-s without definite infuscations. Head and thorax very shining, 



^ 12 

 almost inipuuctate 



9. Tegulse black. Scutellum generally marked with yellow 10. 



— TegulEe never black. Sctitellum generally immaculate 11. 



10. Hind tarsi of 3 always black (in the female they are reddish). Head and 



mesonotiun in both sexes slightly shining between the punctures. A 

 brightly coloured insect, generally with a broad, yellow apical band on 

 the propodeum and each of the segments following it, except the 1st, 

 2nd, and 5th (that on the 4th, especially in the S3, is frequently 

 interrupted in the middle ! ). Occasionally the mesopleurae are slightiy 

 spotted behind with yellow : in more typical specimens they are im- 

 maculate. Labrum sometimes very dusky, but this character also 

 varies. 10-11 mm. long A. marginellus, K\. 



— Hind tarsi reddish in hoth sexesl Exceedingly like marginellus but 

 the puncturation of head and mesonotum coarser and more rugose, so 

 that the surface looks duller. (The antennae are variable in colour, the 

 flagellvun being either black or fulvous. In marginellus it seems to be 

 always black!) A omissus, Forst. 



11. Abdomen coloured much as in marginellus and omissus, but the 



*A .chacffn-i, Kl., which has been recorded as British (but I ^eHeve erroneously) is PracticaUy 

 flTrge and highly coloured arcuatus but with black tegute. See Notes following this Table. 



