American Trypanosomiasis 



523 



the diagnosis, though if they be found the diagnosis is certain. It 

 is usually much better to inoculate i or 2 cc. of the blood of the 

 suspected case into a guinea-pig and then make frequent examina- 

 tions of its blood. Here, again, the common absence of trypanosome 

 forms from the blood complicates matters. If none can at any time 

 be found, the muscles of the guinea-pig must be examined for the 

 dividing forms of the parasites, which are usually quite numerous. 

 Prophylaxis. — ^As the bugs fly it is somewhat difficult to defend 

 the sleeping patient against them, so long as he lives in a carelessly 

 built and thatched country house. Sulphur fumigation and white- 

 washing may help. Well-built habitations with screened windows 

 and the use of mosquito bars should constitute the best defense. 



Lamus (Conokhinus) Megistis (Burn) 



Patton and Cragg* describe this bug as follows: "Dark brown to black. Pro- 

 notum broadly expanded, with two broad raised red Unes extending from the 



Fig. 215.— Lamus (Conorhinus) megistus (female), the insect host and distributing 

 agent of Schizotrypanum cruzi (Chagas). X 2. 



middle of the posterior border, and a red spot on the postero-lateral angles of pro- 

 notum. At the anterior border of the pronotum there are six short spines, three 

 on each side; the most anterior are the longest and project on each side of the eyes; 

 two are situated further back, one on each side of the middle line at the origin of 

 the two admedial ridges; the third spine is situated on a ridge at the junction of 

 the middle and anterior third of the pronotum just above the first pair of legs. 

 Scutellum dark brown with two short red lines converging toward the apex, where 

 they meet; apex red, turning upward and bluntly rounded off. Corium and 

 membrane fuscous, the former with one or more red streaks. Connexivum with 

 six well-marked bright red lines, broader in the male; in both sexes the lines ex- 

 tend round to the ventral border. In the male the last segment, except for a 

 central black mark, is entirely red. Length 30 to 32 mm." 

 The.L. megistus "is almost entirely a domestic insect." "The adults enter 



* "A Text-book of Medical Entomology," 1913. P- 492- 



