26 BULLETIN" 66, UNITED STATES NATIONAL MUSEUM. 



Percentage of parasitism according to species. 



Polistes annularis (Pierce), 1,553 wasps; 17.2 per cent parasitized. 

 Polistes annularis (Hay), 54 wasps; 7.4 per cent parasitized. 

 Polistes annularis (Barber), 35 wasps; 5.7 per cent parasitized. 

 Polistes annularis (McAtee), 105 wasps; 5.7 per cent parasitized. 

 Polistes new species (Crawford), 216 wasps; 2.7 per cent parasitized. 

 Polistes, new species (Cushman), 28 wasps; 3.5 per cent parasitized. 

 Polistes metricus (Austin), 50 wasps; 18 per cent parasitized. 

 Polistes texanus (Skinner), 144 wasps; 23.6 per cent parasitized. 

 Andrena crawfordi (Pierce), 266 bees; 34.6 per cent parasitized. 

 Andrena lapponica (Theobald, 1887), 180 bees; 52.7 per cent parasitized. 

 Andrena lapponica (Theobald, 1888), 60 bees; 90 per cent parasitized. 



Sex of parasites. 



Polistes annularis (Pierce, October), 470 parasites; 65.1 per cent males, 34.9 per cent 



females. 

 Polistes annularis (Hooker, December), 17 parasites; 47 per cent males, 53 per cent . 



females. 

 Polistes annularis (McAtee, November) ; 20 per cent males, 80 per cent females. 

 Polistes annularis (Brues, July), 94 parasites; 96.7 per cent males, 3.3 per cent females. 

 Polistes annularis (Brues, October), 125 parasites; 64.8 per cent males, 35.2 per cent 



females. 

 Polistes gallicus (Rosenhauer), 125 parasites; 64.8 per cent males, 35.2 per cent females. 

 Polistes pallipes (Bowditch, September), 30 parasites; 86.6 per cent males, 13.4 per 



cent females. 

 Polistes pallipes (Dury), 38 parasites; 94.7 per cent males, 5.3 per cent females. 

 Prosopis, species (Saunders), 49 parasites; 65.3 per cent males, 34.7 per cent females. 

 Andrena crawfordi (Pierce, May), 101 parasites; 43.5 per cent males, 56.5 per cent 



females. 

 Andrena pratensis (Friese), 42 parasites; 45.2 per cent males, 54.8 per cent females. 

 Andrena tibialis (Enock, April), 59 parasites; 32.2 per cent males, 67.8 per cent females. 



Maximum parasitism per individual. 



Polistes annularis (Pierce), 1 male wasp with 15 male parasites. 



Polistes annularis (Hooker), 1 male wasp with 3 male, 3 female parasites. 



Polistes annularis (Brues), 1 wasp larva with 31 larval parasites. 



Polistes metricus (Austin), 1 female wasp with 7 male parasites. 



Polistes pallipes (Bowditch), 1 male wasp with 10 male parasites. 



Polistes pallipes (Dury), 1 female wasp with 9 male parasites. 



Andrena crawfordi (Pierce), 1 female bee with 3 female parasites. 



Andrena lapponica (Theobald), 2 female bees with 3 parasites each. 



Andrena nigroaenea (Theobald), 3 female, 1 male bee with 3 parasites each. 



Andrena pratensis (Friese), 1 female bee with 2 male, 1 female parasite. 



Andrena tibialis (Enock), 1 male bee with 3 female parasites. 



Andrena tibialis (Enock), 1 male bee with 1 male, 2 female parasites. 



m .. . • /-d t • n i • (male leaf hopper with 2 male, 2 female parasites. 



Tetiqonia, species (Perkins), 1 pair { „ , , „, r ^ ., _ ' ., 



I female leaf hopper with 3 or 4 parasites. 



In studying these figures, which are gathered under various condi- 

 tions and by different observers, there are certain conclusions which 

 may be drawn with safety. 



1. A large series of observations is always necessary in order to 

 draw valid conclusions. Previous statements that wasps could not 



