CH. V] WASPS 161 



5. Vespa rufa : colour of thorax and shape of face as in (2), (3) 

 and (4), but black markings on abdomen are blurred with 

 bro'wn and not sharply denned. Abdomen glossy. Nests 

 underground. Not uncommon. Armature more robust and 

 darker. 



[Carpenter and Pack-Beresford 1 appear to have satis- 

 factorily established that V. rufa and V. austriaca are but 

 dimorphic forms of the same species. The latter they regard 

 as the ancestral type, the former as a more recent develop- 

 ment. In England the younger and more vigorous V. rufa 

 has almost completely displaced V. austriaca, which however 

 still holds its own in Ireland.] 



6. Vespa sylvestris : colour of thorax and of abdomen as in (2), 

 (3) and (4), but face long, i.e. a well-marked interval between 

 the eyes and base of mandibles. Clypeus with only a small 

 central black spot. Scape of antennae yellow in front in <, 

 $ and $ . Tibiae with long projecting hairs. Stipites of 



armature with inner margin deeply sinuate near the base, 

 then parallel and almost in contact to the apex, where they 

 terminate in a sharp spine without any fringe of hairs. Nests 

 on branches of trees, bushes, etc. ; occasionally underground, 

 near surface, or in old tins, pots, etc. Common. 



7. Vespa norwegica : colour of thorax as in (2) etc. ; shape of 

 face, scape of antennas and tibiae as in (6). Clypeus with 

 broad central black line often dilated in middle. Abdomen 

 generally reddish at base. Stipites of armature with inner 

 margin slightly sinuate near the middle, and far apart 

 throughout their length ; their apex furnished with a spine 

 and a dense fringe of hairs beyond it. Nests on branches 

 of bushes and shrubs, occasionally on trees. Fairly common. 



[The males of each species can always be distinguished from 

 females, whether "queens" or "workers," by the following: an- 

 tennae of males have 13 joints; females only 12 joints; the 

 abdomens of males have seven visible segments, those of females 

 only six; the wings of males are longer and relatively narrower 

 than those of females ; and lastly, males cannot sting.] 



1 Irish Naturalist, xn. 9. Sept. 1903. 

 L. 11 



