84 AGRICULTURAL EXPERIMENT STATION. 



For some reason no large collections and examinations were 

 made in August ; but at that time my own examinations showed 

 the largest percentage of parasites in material sent in from Ocean 

 and Atlantic Counties. 



That this parasite is a very material check to the multiplication 

 of Culex sollicitans seems certain, for in no case where a para- 

 sitized specimen was examined were ovaries developed. In fact 

 the worms, for there may be several in one insect, so completely 

 fill the body cavity that there is room for nothing else. Of course 

 the infested migrants are sterile in an}^ case; but in the collect- 

 ions made by Mr. Viereck especial effort was made to get at the 

 localities where oviposition was going on, and the collections 

 containing- the greatest percentage of parasitized specimens con- 

 tained also the largest percentag-e of specimens with fully de- 

 veloped ova in those not infested. It need hardly be said, how- 

 ever, that the check was not sufficient to reduce the species 

 appreciably even in those localities where it would seem to have 

 been most effective ; while the only localities where sollicitans 

 was really rare in 1904 are those where the parasite does not 

 occur at all. As to the effect upon the individual, it probably 

 shortens life to some extent. It does not prevent migration be- 

 cause parasitized specimens have been taken far inland ; nor does 

 it prevent feeding, for I have killed specimens that have actually 

 bitten me. In fact I sat for an hour one afternoon at Anglesea 

 capturing such specimens as came to bite and examined for para- 

 sites, and found that nearly or quite half were infested. At New 

 Brunswick the percentage was not so great; but was decidedly 

 appreciable. As to whether the parasite can be practically em- 

 ployed I cannot say. Nothing is known of its life history nor 

 where it passes its early stages and until this is worked out any 

 statements would be mere guess work. The necessary studies 

 must be made by one fully familiar with such animals and I have 

 presented the matter to Surgeon General Wyman, of the Marine 

 Hospital Service, as a subject meriting the attention of his de- 

 partment. 



In the course of his work for this investigation in 1902, Dr. 

 H. P. Johnson found the young of an intestinal worm in an 

 Anopheles larva, and he suggests that it may bear some relation 

 to this Aganwmermis; but that seems scarcely possible, since the 

 waters inhabited by the Anoplieles never maintain sollicitans 

 and vice versa. For the present the worm offers no prospect of 

 a natural control of its host. 



