No. 22.] HYMENOPTERA OF CONNECTICUT. 675 



North Haven, 3 August, 1905, Canterbury, 14 August, 1905 

 (B. H. W.) ; Hartford, 22 August, 1892 (S. N. D.). 



P. (P.) solivagus Say. Howard, Insect Book, PI. iii, 

 Fig. 31- 



Easily determined by the above table. There is a yellow spot 

 between the bases of the antennae, the scape of which is yellow in 

 front. The metanotum is black. The markings are yellow. 



Hartford (S. N. D.) ; Rockville (H. L. V.); Stafford 

 (W. E. B.) ; New Haven, 24 August, 1906, on goldenrod 

 (P.L.B.). 



P. (P.) politus Say. 



No free pale spot between the bases of the antennae ; metano- 

 tum pale. Markings whitish. 



Poquonock, 27 June, 1905, on milkweed flower (H. L. V.). 



Trypoxylonin^. 



This subfamily is represented in the State by the genus 

 Trypoxylon only. In some other parts of the Nearctic region are 

 found the genus Pison and allies which belong to this subfamily. 



Tr5rpoxylon Latreille. 



Elongate wasps, with the abdomen narrow and longer than the 

 head and thorax; head transverse; inner margins of the eyes 

 strongly emarginate within ; radial cell of the fore wings pointed 

 at the apex ; one cubital and two discoidal cells sharply defined, 

 the second cubital and third discoidal cells indicated by darkened 

 lines. Black, or black marked with red. 



These wasps are as a rule lazy when it comes to making a nest 

 of their own, and usually choose a hole made by some other insect. 

 The Peckhams record rubrocinctum as using holes made in the 

 mortar of a brick wall, holes made in a post and in straw, the open 

 ends of which were exposed. Other species choose nests made 

 by other means, but bidentatum makes its own nest in stems of 

 plants. Some of the species even use abandoned nests of the 

 mud-daubers. When the nest is made in a burrow, the cells are 

 separated by mud partitions, and the nest is sealed with mud. 

 The Peckhams found that the species they studied used spiders 

 only to provision their nests, but Ashmead records certain species 



