226 THE BLOWFLIES OF NortTH AMERICA 
of Western North America, p. 587, 1926; Richards, Roy. 
Ent. Soc., London, Trans. 74(2) :256, 1926; Townsend, M. 
M., Ent. Soe. Amer. Ann. 21:124, 1928; Roberts, Ent. Soe. 
Amer. Ann. 23:790, 1930; Curran, Amer. Mus. Nat. Hist. 
Bull. 61:89, 1930; Kingsecote, Ontario Ent. Soc. Ann. Rpt. 
62 :92, 19381; Aubertin, Linn. Soc. London Jour., Zool. 38 :400, 
1933. 
Lucila illustris (Meigen) Aubertin, Linn. Soe. London Jour., 
Zool. 38 :402, 1933. 
Lucilia caesar (l.) as determined by Villeneuve, Lundbeck, 
Stein, Aubertin, Richards, Riedel, Engel, and other European 
dipterists, apparently does not occur in North America, but 
since it occurs in eastern Asia, as well as in Europe, it might 
perhaps be expected in collections from Alaska or western Can- 
ada. The Lucilia caesar of North American authors is usually 
Lucila alustris (Meigen). Coquillett determined a number of 
species of both Phaenicia and Lucilia as caesar, as did other 
North American dipterists early in the present century, and 
many of the early references to either caesar or to tllustris may 
be inaccurate. 
Because caesar may occur in North America, the following 
key is presented to separate allustris and caesar. 
1. Male with frontale obvious throughout and almost as wide as 
parafrontale at lunule, with epistoma slightly narrowing 
and vibrissae set 2.3 apart; both sexes with hindmost prea- 
erostichal bristles usually placed 2.8 before the suture; fe- 
male with front at narrowest 0.32 of head width, 0.35 at 
lunule and. vibrissae set 2.6.apart.......... . 1.00 
PR ot rn Ue Ase ea eee Lucilia illustris (Meigen). 
Male with frontale obsolete at narrowest portion of parafron- 
tale, the eyes nearly contiguous for a short distance, epistoma 
nearly as wide as clypeus and the vibrissae set 2.8 apart; 
both sexes with hindmost preacrostichal bristles placed 2.6 
before the suture; female with front at narrowest 0.31 
of head width, 0.84 at lunule, and vibrissae set 0.30 apart 
ACE 250 Ee I) ARS ies Lucilia caesar (Linnaeus). 
A blue-green species with strong wiry bristles on the subcostal 
sclerite. 
Male. Head (pl.5,B) width 11.9; length at antenna 5.2 and 
at vibrissa 5.6; oral margin considerably protruding beyond 
vibrissal angle in profile; eye height 7.6; head height 9.8; epis- 
toma orange; metacephalon produced slightly posteriorly and — 
