718 Hymenoptera in America North of Mexico 



pleuralis pleuralis (Cresson). N. H. s. to n.w. S. C, w. to Mich., e. Iowa, Ark., and s. Tex. Host: 

 Syrphid predator of grape aphid. 

 Bassus pleuralis Cresson, 1868. Amer. Ent. Soc, Trans. 2: 111. 9. 

 pleuralis syrphicola (Ashmead). Southern Alta. and s. B. C. s. to n. Colo., n. Utah, n.e. Nev., 

 and central Calif. Host: Metasyrphus perlexus (Osb.), Scaeva pyrastri (L.). 

 Bassus syrphicola Ashmead, 1890 (1889). U. S. Natl. Mus., Proc. 12: 439. 6, 9. 

 quadrangularis (Dasch), n. comb. Eastern Mass., n.e. N. J., Colo., s. Alta., n. Idaho, n. Yukon, 

 interior Alaska, B. C. 

 Homotropus qiiadrangularis Dasch, 1964. Amer. Ent. Inst., Mem. 3: 106. S , 9. 

 robsonensis (Dasch), n. comb. Southeastern B. C. Known only from two specimens. 

 Homotropus robsonensis Dasch, 1964. Amer. Ent. Inst., Mem. 3: 183. 6, 9. 



robustus Davis. Southeastern Mich., s. Alta., s. B. C, Wash. 



Syrphoctomis robustus Davis, 1895. Aiiier. Ent. Soc, Trans. 22: 25. S. 



rufulus (Dasch), n. comb. Southern Maine w. to s.w. Ont. and interior Alaska, s. to n.w. S. C. 

 and n. 111. Dasch (1964) stated that one of the paratypes was from "Louisiana (no 

 locality)"; his dissertation (Dasch, 1953) indicated that the specimen was a male from the 

 C. F. Baker collection and was in the U. S. Natl. Museum collection. I find no paratype 

 from La. in that collection and therefore cannot verify from the Baker notebook that it 

 was really collected in La. (in rare cases the notebook data pertaining to a particular 

 "Baker number" do not agree with the locality on the specimen label). 

 Homotropus rufulus Dasch, 1964. Amer. Ent. Inst., Mem. 3: 104. 6, 9. 



Taxonomy: Dasch, 1953. Taxonomic study Nearctic Diplazoninae, Ph. D. Thesis, Cornell 

 Univ., p. 217. 

 sicarius (Dasch), n. comb. Newfoundland (n. Labrador), n. Que., N. W. T., interior Alaska. 



Host: Simuliid. 

 Homotropus sicarius Dasch, 1964. Amer. Ent. Inst., Mem. 3: 161. cJ, 9. 

 signatus (Gravenhorst). Newfoundland (insular) and n. Que. w. to n. Alaska, s. to N. J., s. Ohio, 



n. Iowa, n. Colo., and n.w. Oreg.; Eurasia. Host: Platycheirus erraticus Curran, 



Spkaerophoria contigua Macq. 

 Bassus sig7iattis Gravenhorst, 1829. Ichn. Europaea, v. 3, p. 325. 9. 

 Tryphon nigricomis Zetterstedt, 1838. Insecta Lapponica, Hym., p. 399. 9. 

 Tryphon compressiventris Cresson, 1868. Amer. Ent. Soc, Trans. 2: 105. cJ, 9. 

 Homotropus kygrobius Thomson, 1890. Opusc Ent. 14: 1524. cJ, 9. 

 Zootrephes montanus Davis, 1895. Amer. Ent. Soc, Trans. 22: 24. i, 9. 

 tarsatorius (Panzer). Northern Que. w. to Alaska, s. to N. Y., n. Mich., Colo., and s.w. Oreg.; 



Eurasia. Host: Syrphid spp. 

 Bassus tarsatorius Panzer, 1809 (1806-1809). Faunae Ins. German., Heft 102, pi. 19 



[female]. 

 Bassus exsultans Gravenhorst, 1829. Ichn. Europaea, v. 3, p. 328. S. 

 Bassus insignis Gravenhorst, 1829. Ichn. Europaea, v. 3, p. 349. 9 . 

 Bassus flavus Desvignes, 1862. Ent. Soc. London, Trans. 10: 219. 6. 

 Bassus pulckellus Desvignes, 1862. Ent. Soc. London, Trans. 10: 221. S. 

 Bassus indicus Cameron, 1909. Bombay Nat. Hist. Soc, Jour. 19: 728. i. 

 Homoporus flavitrockantenis Uchida, 1956. Insecta Matsumurana 19: 99. 6, 9. 

 teres (Dasch), n. comb. Colo. Ecology: Occurs in the Rocky Mts. at altitudes between 9600 ft. 



and 12000 ft. 

 Homotropus teres Dasch, 1964. Amer. Ent. Inst., Mem. 3: 113. 6, 9. 



venustus (Dasch), n. comb. Colo., n. Utah, s. Idaho. 



Homotropus venustus Dasch, 1964. Amer. Ent. Inst., Mem. 3: 138. 6,9. 

 vitreus (Dasch), n. comb. Newfoundland (n. Labrador) w. to Alaska, s. to N. S., n. Mich., n.w. 

 Wyo., and n.w. Calif. 



Homotropus vitreus Dasch, 1964. Amer. Ent. Inst, Mem. 3: 173. cJ, 9. 



Genus XESTOPELTA Dasch 



Xestopelta Dasch, 1964. Amer. Ent. Inst., Mem. 3: 208. 



Type-species: Syrphoctonus vertebratus Cushman. Orig. desig. 



