82 AGRICULTURAL EXPERIMENT STATION. ■ 



9401, in poor condition; collected by Dr. John B. Smith, New 

 Brunswick, N. J. 



"In the summer of 1889 I collected a number of Agamomer- 

 niis sp., from mosquitoes of the species Cidex nemoralis, taken 

 in the vicinity of Leipzig, Saxony. Whether they were identical 

 with the present form I am unable to state. The interesting fact 

 may be mentioned, however, that the Leipzig Agauiomermis 

 was distinctly injurious to the mosquitoes. It was found in the 

 abdominal cavity of larvae, pupae, and adults, so that infection 

 must have taken place in the water, namely, in the larva and 

 pupal stages of the Cidex. The infested insects were very slug- 

 gish in their movements and could usually be recognized as 

 diseased. Many of them died from the effects of the parasite, 

 and the ovaries of infected females were under-developed. 

 Professor Leukart informed me at that time that he had fre- 

 quently found Culex nemoralis infected with this worm, and 

 that during the years that the worms were most common the 

 mosquitoes seemed to be less numerous. 



"These cases represent interesting instances in nature, where 

 a pest is subject to other pests, which tend to hold the former in 

 check. 



"At least two other species of Merinis should be placed in the 

 collective group Agauiomermis, namely, Agamoinermis gain- 

 niari (von Linstow, 1892), parasitic in Gammarns pulex, and A. 

 sialidis (von Linstow, 1892), parasitic in Sialis hitaria. 



"At a time when mosquitoes are subject to such careful study, 

 because of the important relations they bear to public health, 

 especially in connection with malaria, yellow fever, etc., it is of 

 interest to determine what parasites naturally infest them. This 

 determination has its practical as well as its scientific value, for 

 it enables us to eliminate certain nonpathogenic parasitic organ- 

 isms from the life cycle of pathogenic organisms, stages of which 

 may be found in mosquitoes. It further has its direct practical 

 bearing in that the parasites of mosquitoes may multiply to such 

 an extent as to become important factors in killing the insects, 

 or at least rendering them less fertile. 



"Quite recently several parasites have been described for the 

 Culicidje. Ross (1895) has found intestinal gregarines in mos- 

 quito larvae in India. Perroncito (1899) has found a filamen- 

 tous phytoparasite in Anopheles collected near Turin, Italy. 

 Laveran (1902) has described a pathogenic yeast in the abdom- 

 inal cavity of Anopheles maciilipennis collected in Spain, and he 

 reports various Acarines as external parasites of the Culicidae. 

 Leger (1902) has described a parasitic flagellate (Crithidia fas- 

 ciculata) in the intestine of the adult female of Anopheles inacn- 



