CONTROL OF CHIRONOMIDS 477 



breeding midges, Forcipomyia utoe and F. townsendi, have been 

 incriminated by Townsend as the carriers and intermediate hosts 

 of the protozoan parasite causing " uta " in Peru. Uta (see 

 Chap. V, p. 86) is a form of leishmaniasis occurring on the 

 western face of the Andes. According to Townsend, Leishman 

 bodies are found in abundance in the digestive tract of these 

 midges, and injection into laboratory animals of serum contain- 

 ing the ground bodies of captured insects resulted in the forma- 

 tion of sores which Townsend regarded as uta, and from which 

 he obtained a few Leishman bodies. Two cases are cited, also, in 

 which uta sores developed following the bites of the midges, and 

 supposedly due to them. According to Townsend the infection 

 is evidently transmitted by contamination of the wound made by 

 the proboscis with infected excrement. That these insects are 

 really the transmitters of uta in man cannot be considered as 

 proved, but it must be regarded as a possibility. It should be 

 recalled that many insects have been accused of carrying Oriental 

 sore and allied diseases, among which are blackflies {Simulium), 

 sandflies (Phlebotomus) , gadflies (Tabanidse) and others, and it 

 is open to question whether any insect which harbors a Her- 

 petomonas in its gut may not be able to infect vertebrates if the 

 germs reach the blood. If so, these midges must be regarded as 

 conveyors of a Leishmania infection. 



Little is known about these species of Forcipomyia, but it is 

 probable that their habits are similar to those of better known 

 species. In the North American species, the larvse (Fig. 217) 

 are slender whitish worms about one-eighth of an inch in length 

 which live in damp places in moss and under bark, stones, etc. 

 The pupse are pale yellowish, later becoming brown. 



Control. — The control of the aquatic biting midges is not 

 difficult, and can be accomplished in the same manner as can the 

 control of swamp-breeding mosquitoes, by draining, stocking with 

 natural enemies or oiHng. It is improbable that these midges 

 breed to any extent in transient pools, for most of them, at least, 

 prefer pools of standing water, abundant in organic debris and 

 microscopic organisms. The terrestrial-breeding forms of For- 

 cipomyia and Ceratopogon, like the sandflies, are practically im- 

 possible to exterminate. 



Much protection from the adults can be obtained by the use 

 of repellents as advised for mosquitoes and sandflies (see p. 455). 



