REVISION OF STEEPSIPTERA PIERCE. 23 



POLISTES VARIATUS Cresson. 



On October 18, 1903, Mr. Crawford took at West Point, Nebraska, 

 200 wasps of this species, all unstylopized, of which only 2 were 

 males. 



NECTARINA LECHEGUANA Latreille. 



In December, 1905, Mr. A. C. Morgan took a nest of Nectarina 

 lecheguana at Hidalgo, Texas, and from this nest Mr. Crawford 

 examined about 2,500 wasps for parasitism without finding a single 

 case. Du Buysson (1905 a) states that he has never met a case of 

 stylopization in Nectarina. 



PROSOPIS, species. 



Saunders (1852) took 22 specimens of Prosopis, in which he found 

 32 male and 17 female parasites; 14 bees contained male parasites 

 and 8 contained female parasites. No bee was found containing 

 both sexes. 



ANDRENA CRAWFORDI Vieieck. 



Between April 26, 1906, and May 23, 1906, at Dallas, Texas, a 

 large number of this species of bee were collected by Messrs. Crawford, 

 Bishopp, Jones, Pratt, and the writer from the flowers of Sitilias 

 caroliniana, Serihea opposite 'folia, Lindheimera texana, and Engel- 

 mannia pinnatifida. Following is a table of the captures for the 

 entire period. All parasites were beneath the fourth segment. 



151 male bees; 120 unparasitized, 31 parasitized. 



115 female bees; 54 unparasitized, 61 parasitized. 



266 bees; 174 unparasitized, 92 parasitized. 



56.7 per cent of the bees were males, 43.3 per cent females. 



33.6 per cent of the parasitized bees were males, 66.4 per cent females. 



79.4 per cent of the male bees, unparasitized; 20.6 per cent parasitized. 



46.9 per cent of the female bees, unparasitized; 53.1 per cent parasitized. 



65.4 per cent of all the bees unparasitized; 34.6 per cent parasitized. 



The following table gives more specifically the extent of parasitism, 

 bringing out the percentage of sexes of the parasites and their relation 

 to each other: 



1 female bee with 3 female parasites= 3 parasites= 3 females. 



1 male, 6 female bees with 2 female parasites =14 parasites = 14 females. 



23 males, 17 female bees with 1 female parasite =40 parasites= 40 females. 



7 males, 37 female bees with 1 male parasite =44 para^ites=44 males. 



31 males, 61 female bees with 101 parasites=44 males, 57 females. 



43.5 per cent of all parasites were males. 

 56.5 per cent of all parasites were females. 



ANDRENA LAPPONICA Zetterstadt. 



Theobald (1892) gives a few imperfect records of his observations 

 in this species. The collecting was done at St. Leonards-on-Sea, 

 England. 



In 1887, 105 bees out of 180 taken were parasitized=52.7 per cent; 

 In 1888, 54 bees out of 60 taken were parasitized =90.0 per cent. 



