British Hymenoptera. 167 



DIPLOPTERA. 



(2) 1. Abdomen petiolated ; 1st joint much narrower than 



2nd . . . . . . . . . . . . . . Eumenes. 



(1) 2. Abdomen not petiolated; 1st joint not much narrower 



than 2nd. 

 (4) 3. Intermediate tibiae with one spine only at the apex Odynervs. 



(3) 4. Intermediate tibias with two spines at the apex . . Vespa. 



Vespa, Linn. 



Linn., Syst. Nat., ed. x., p. 572. 



This is the only genus of the social wasps that we 

 have in this country, and can scarcely be confounded 

 with any other. The communities are composed 

 of (? , ? and ? , and form their nests in the ground or in 

 trees or bushes. The 2 hybernates in an impregnated 

 condition, and the new brood ai)pears about August. All 

 our species are ornamented with bright yellow markings. 

 Labial palpi 4-jointed ; maxillary 6-jointed. Wings with 

 three submarginal cells. 



(2) 1. Thorax with brown and red markings . . . . crahro. 

 (1) 2. Thorax with black and yellow markings. 



(10) 3. Eyes touching, or almost touching, the base of the 



mandibles. 



(9) 4. Markings of the body all black and clearly defined. 



(8) 5. Basal joint of antennas black in the $ and § • 



(7) 6. 5 ; 1st segment of body with a continuous black 

 band at the base. ^ ! clypeus with a black 

 central line generally widened in front, g^ more 

 pubescent . . . . . . . . . . . . vulfjaris. 



(6) 7. $ ; 1st segment with three basal spots, the central 

 one largest. ^ ; clypeus usually with only three 

 black dots. ^ less pubescent .. .. .. nermtniicn. 



(5) 8. Basal joint of antenna? yellow in front in J and § ; 



<y unknown tirhorca. 



(4) 9. Markings of body, especially near the base, more 

 or less undefined, fading off into marlcings of a 

 brownish or reddish hue .. .. .. .. riifa. 



(3) 10. Eyes not nearly touching the base of tlie man- 



dibles. 

 (12) 11. Larger; no reddish colour on the body .. .. sylvestris. 



(11) 12. Smaller ; sides of the body at the base more or less 



reddish .. .. " norvegica. 



