^o. 2242. MORPHOLOGY OF THE STREPi<lPTERA— PIERCE. 397 



Polistes variatus (McAtee), 66 parasites; 33.3 per cent males, 66.7 

 per cent females. 



Stenocrunufi sacvhatioor-us (Jones), 77 parasites: 62.3 per cent 

 males, 37.7 per cent females. 



MAXIMUM PARASITISM TO THE INDIVIDUAL. 



Polistes annularis (Nebraska), 1 female wasp with 11 male para- 

 sites, 1 female Avith 8 male parasites. 



Polistes variatus (McAtee), 3 female wasps with 4 parasites each. 



Stenocranus saccharivous (Jones), 1 male leaf hopper with 4 male, 

 1 female parasite. 



To the list of exceptions in which there are more female than male 

 parasites^ should be added the above-mentioned record of Polistes 

 variatus, which, like the other two exceptions, is a winter and spring 

 record. 



It is of especial interest that in Homoptera the female parasites 

 are placed farther forward than in Hymenoptera, while the males 

 are farther back. In Hymenoptera the third segment is the normal 

 position for males and the fifth for females. In Delphax this is 

 directly reversed. This is probably because the Hymenopterous 

 parasite has the female largest, while the Homopterous parasite has 

 the male largest. 



Of special interest are the two occurrences of dryinids and strep- 

 siptera in the same host. 



//. Alteration of general features. . * 



e. Punctuation. — According to Smith and Hamm (1914), para- 

 sitized Andrena nigroaenea males " tend to have the abdomen dull, 

 very much as in the female, and this appears to be due to the deeper 

 and more frequent punctuation on the abdomen and not to a greater 

 hairiness. The stylopised females do not appear to be affected either 

 in punctuation or hairiness." 



/. Wing venation. — In Bulletin 66, under the paragraph 5c, several 

 instances of alteration of wing venation characters in bees due to 

 stylopization were recorded. 



An excellent example of how parasitism renders this valuable 

 character instable is illustrated on Plate 73, which shows the wings 

 of four individuals of Agallia uhleri parasitized by Agalliaphagu,s 

 uhleri. The number of apical cells in the wings varies from three 

 to six and various unusual veins occur in unexpected places. Fig- 

 ure 2 on this plate is almost a normal wing. The other wings show 

 several very remarkable features, such as the veins outside the mar- 

 ginal in figure 3 and the complete development of all the anal veins 

 in figure 4. The wing in figure 2 has a total of 14 cells, that in fig- 

 ure 4 has 18 cells. 



1 Bulletin 66, p. 27. 



