No. 22.] HYMENOPTERA OF CONNECTICUT. 64I 



wasps, the familiar types of which are the hornet and yellow- 

 jacket. These wasps build nests of paper which is made by 

 chewing wood into small bits. In the Vespini the nest is 

 entirely enclosed leaving only a small circular hole for the 

 entrance of the wasps. In the Polistini, as represented in our 

 region, the nest is broad and flat without an enclosing envelope. 



The larvae of these insects are fed mostly upon the chewed- 

 up remains of Lepidopterous larvae, although other larvae, 

 pollen, and honey are used. The larvae are fed from day to 

 day, no food being stored for them. 



This subfamily is parasitized by Diptera, Hymenoptera 

 and Strepsiptera. 



Vespini. 



According to the writer's views this subfamily may be 

 divided into two tribes by the following characters : 



Key to Tribes. 



Hind wings long, without an anal lobe; first abdominal seg- 

 ment very broad, sharply truncate anteriorly; mesepister- 

 num without an anterior dorsal plate vespini p. 641 



Hind wings with distinct anal lobe; first abdominal segment 

 subpetiolate, petiolate or conical, never abruptly truncate 

 at base; mesepisternum with a separate dorsal plate along 

 anterior margin polistini p. 643 



VESPINI. 

 Key to Genera. 

 Vertex extending much above eyes; ocelli much below 



supraorbital line; posterior orbits broad Vespa p. 641 



Vertex not extending above eyes; ocelli slightly caudad of or 

 tangent with supraorbital line; posterior orbits narrow.. 



Vespula p. 642 

 Vespa Linnaeus. 

 This genus is represented by a single species, supposedly 

 introduced, which is brown and yellow and very large, having a 

 length of 18-22 mm., and builds its nest in hollow trees. 

 V. crabro Linnaeus. Giant Hornet. PI. viii, Fig. 10. 

 New Haven, 13 June, 1900, i October, 1903 (W. E. B.), 30 

 June, 1901 (A. L. Winton), 2 November, 1905 (G. R. Bradley), 

 8 October, 1908 (B. H. W.) ; Hamden, 28 September, 1901 

 (R. C. Horsfall) ; Darien, 13 September, 1906 (E. H. Delafield) ; 



Plantsville (A. Shepard). 

 41 



