SPHAEROCERA IN CENTRAL AND SOUTH AMERICA — RICHARDS 241 



22. Sternite 3 dotlike, sternite 4 pyriform. Anterior part of prosternum wider. 

 Abdominal pale spot as S. ecuadoria, new species (Ecuador). 



S. trapezina, new species 



Sternite 3 small but rectangular, sternite 4 rectangular, nearly three times 



as long as broad. Abdominal pale spots larger (St. Vincent and Grenada 



B.W.I.) S. bimacuiata, Williston 



The Association of Acarina with Subgenus Parasphaerocera 



Four of the males and six of the females of S. (P.) ecuadoria had 

 a large mite hanging beneath the mentum. All the mites were 

 attached with their heads by the foramen of the fly and with their 

 dorsum directed downward. One of the mites was determined by 

 Mr. E. Lindgren as Macrocheles sp. aff . insignitus Berlese. A specimen 

 of S. (P.) xiphosternum from Panama, Albrook Field, had a similar 

 mite on its mentum. 



Literature Cited 



Malloch, J. R. 



1913. Description of new species of American flies of the family Bor- 



boridae. Proc. U.S. Nat. Mus., vol. 44, no. 195S, pp. 361-372. 



1914. A new Borborid (Diptera) from Panama. Ent. News, vol. 25, p. 31. 

 1925. A synopsis of New World flies of the genus Sphaerocera (Diptera; 



Borboridae). Proc. Ent. Soc. Washington, vol. 27, pp. 117-123. 

 Richards, O. W. 



1961. Diptera (Sphaeroceridae) from South Chile. Proc. Roy. Ent. Soc. 

 London, ser. B, vol. 30, pp. 37-68, 13 figs. 

 Spuler, a. 



1924. North American species of the genus Sphaerocera and Aptilotus (Dip- 

 tera-Borboridae). Pan-Pacific Ent., vol. 1, pp. 66-77, 4 figs. 

 Williston, S. W. 



1896. On the Diptera of St. Vincent (West Indies) . Trans. Ent. Soc. London, 

 pp. 253-446. 

 Young, Benjamin P. 



1921. Attachment of the abdomen to the thorax in Diptera. Cornell 

 Univ. Agric. Exp. Sta. Mem., no. 44, pp. 255-306, illustr. 



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