NO. 2242. MORPHOLOGY OF THE STREP81PTERA— PIERCE. 399 



active spermatozoa. On mounting in water their movements could 

 be plainly seen through the walls. Their form was normal, and they 

 behaved in the usual manner when treated with fluids. 



Smith and Hanma (1914) found in 20 females Andrena nigroaeTiea 

 the ovary very greatly reduced in size and incapable of producing 

 mature ova. They gave illustrations to illustrate the extent of the 

 reduction which occurred with both male and female parasites. 

 They found no effect on the male testes or the production of 

 spermatozoa. 



The writer has already mentioned the reduction of the ovary in 

 the Polistes hellicosus taken in Arizona. Only one mature ^gg was 

 contained in the ovaries, these organs being crowded into a very 

 small terminal space. 



A still later record is that of the parasitized OncoTnetofia v/ndata^ 

 recorded above, in which the reproductive organs were completely 

 destroyed. 



8. Effects upon normal functions. 



Smith and Hamm (1914), with regard to Andrena nigroaenea^ 

 write : 



We also find that stylopised females never carry any pollen on their seopae, 

 in marked distinction from the normal females, the majority of whicTi are 

 found with their seopae plastered with pollen, as shown in figure 18. The 

 stylopised females have evidently lost the instinct for collecting pollen, though 

 they still continue to visit the burrows. Of the hiindred or so stylopised females 

 examined, not a single individual had pollen on it. 



This observation conforms with Perez's generalizations; but it 

 must be remembered that the present writer has cited Andrena craw- 

 fordi as often carrying pollen when parasitized. ' 



BIOLOGY OF THE PARASITE. 



Fertilization. 



The question of fertilization of the Strepsiptera is still a matter 

 of controversy. Although the evidence favoring the belief that 

 fertilization occurs is very strong, there are a number of writers who 

 do not accept it as even a possibility. 



The evidence pointing toward fertilization is based (1) upon 

 Smith and Hamm's (1914) statement that "the male does not show 

 any trace of degeneracy in its internal reproductive organs, vesiculae 

 seminales being crowded with active spermatozoa;" (2) that many 

 observers have noted the males visiting parasitized hosts containing 

 females; (3) that males have actually been observed in copulation 

 by Sagemehl (1882) on Andrena par vula, by Crawford (Pierce. 1909) 

 on Panurginus innuptus, by Muir (1906) on Perkinsiella vitiensis, 

 and by Crawford on Andrena, species (June 12, 1916) in Montgomery 

 County, Maryland. 



