no. 2173. A REVISION OF THE BEMBICINE WASPS— PARKER. 123 



with lateral apical spots, small lateral spots on sternites 2-4, femora, 

 distally, tibiae except spot on first and second pair below, and tarsi 

 in varying degree, white or pale-yellowish white. The wings are 

 hyaline. The f rons, vertex, occiput, thorax and median segment are 

 clothed with unusually long, dense, white pubescence, especially 

 conspicuous on the sides of the thorax and on the dorsum and postero- 

 lateral angles of the median segment. 



Length. — 9-13 mm. 



The pubescence on the male is not conspicuously different from that 

 on mondonta except that the process on the second sternite is hirsute, 

 but on the female it is so markedly different as to furnish a basis for 

 distinguishing the two species. The maculations show but slight 

 variations ; the tarsi may be pale with only a brownish shade or they 

 may be decidedly dusky, the distal segments always darker than the 

 proximal ones; on the males the discal marks on the scutum are 

 frequently lacking, the mesopleura is usually black, and the black 

 basal border of the tergites varies in extent; on the female the clypeus 

 may be wholly yellow or it may have the basal border black; the 

 emarginations or sinuations of the anterior border of the tergal 

 fasciae vary in extent but are never very prominent ; on a great many 

 of the females from Arizona the black color, especially on the abdo- 

 men, is replaced by brown of varying degrees of intensity. Since 

 the series shows all shades from light brown to black this lighter color 

 is believed to show simply a teneral condition. 



Habitat. — Texas, New Mexico, and Arizona. 



Number of specimens examined — Males, 19; females, 33. 



Type, allotype, and paratype. — Cat. No. 19673, U.S.N.M. 



BIOLOGY. 



Much valuable work on the biology of various species of Bembicine 

 wasps has been done, especially in Europe, but when we compare the 

 number of species whose lif e history and habits have been investigated 

 with the number of those about which we know practically nothing 

 we wonder why these interesting insects have been so greatly neglected. 

 With respect to the life-history and habits of species of Steniolia I 

 have found in the literature consulted a single observation reported, 

 that given by J. C. Bradley, in which he states that he found Steniolia 

 duplicata Provancher in California sleeping in clusters on the stems of 

 plants. Of the habits and activities of species of StictieUa I have 

 found no report whatever. Among the species of this genus listed in 

 this paper specimens of two (formosa and melanosterna) were found 

 that had been collected while holding in their grasp adult forms of 

 diurnal Lepidoptera. The biology of species of Stictia and Bicyrtes 

 is better understood, but the greatest amount of attention and 

 observation, both in Europe and in America, has been devoted to 

 various species of the genus Bembix. 



