NO. I BLACK FLIES OF GUATEMALA — DALMAT 37 



tempisque Pittier (tempisque), Ficus hemsleyana Standi, (amate), 

 Calocarpum maminosimv Pierre (zapote), Mangifera indica L. 

 (mango), and Struthanthus orbicularis (H.B.K.) Blume (matapalo). 

 These represent the first records of diurnal resting places of black 

 flies. Used in conjunction with information concerning the flight 

 range and longevity of the anthropophilic species (see section on 

 ecology), these findings can be of great importance in any considera- 

 tion of control of the adult black flies. 



ANIMAL ASSOaATIONS 

 The only animals that can be considered of any interest or im- 

 portance in relation to onchocerciasis are those that may serve as 

 reservoirs or vectors of the disease, or those that may in some way 

 affect the incidence of the vectors by their predatory or parasitic habits. 



RESERVOIRS AND VECTORS 



There have been very few studies concerning possible animal reser- 

 voirs of Onchocerca volvulus (Leuckart, 1893) Railliet and Henry, 

 1910. None of the filariids of the genus Onchocerca taken from ani- 

 mals other than man have proved to be O. volvulus. Blacklock's 

 (1926b, 1927) attempts to transmit the infective larvae of 0. volvulus 

 to monkeys by intracutaneous and subcutaneous injections resulted 

 negatively. 



Brumpt (1904) suggested that Glossina spp. or Simulium spp. must 

 be the vectors of Onchocerca volvulus in Central Africa since all the 

 cases he had studied were located near the banks of rivers where these 

 insects were prevalent. Leiper (1914), working in Nigeria, did the 

 first experimental work in the transmission of this parasite. He suc- 

 cessfully fed Stomoxys nigra and 6". calcitrans with microfilariae but 

 no development took place in the insects. Similar experiments carried 

 out by Rodhain and van den Branden (1916) with Aedes (Stegomyia) 

 aegypti and Cimex hemipterus yielded negative results at the end of 

 4 days. 



Robles (1919), after discovering the presence of onchocerciasis in 

 Guatemala, initiated epidemiological studies in the disease zone to de- 

 termine the mode of transmission. He reasoned that since the inhabit- 

 ants of fincas below the infected zone drank water from the same 

 streams that both supplied water to the people of the infected region 

 and served as the outlet for their sewerage, it was unlikely that the 

 disease organisms were transmitted in the water or excrement. Robles 

 also found that, although many species of blood-sucking arthropods 



