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MEDICAL ENTOMOLOGY 



Body not so dark, greyish ; macrochaetae and bristles of 

 mesopleura either entirely yellow or only partly so ; palps 

 pale yellow. Proboscis and basal segment of antenna red 

 or yellow ; legs pale, wings hyaline ; veins yellow 



Bristles and macrochaetae of scutellum entirely black or only 

 partly so ; bristles of abdomen black ; markings on abdo- 

 men somewhat dark ; femora always black. Palps and 

 basal segments of antennae dark yellow. Large sized 

 species .......... 



Bristles and macrochaetae of thorax and abdomen clear 

 yellow. Longitudinal band of abdomen distinct or absent ; 

 femora sometimes yellow ; palps and basal articles of 

 antennae clear yellow. Small sized species (3'5 to 4 mm.) 

 North Africa 



5. 



Frontal band red or reddish ; length 4 to 4 '5 mm- 

 America and Hawaian Islands . . 



North 



Frontal band black with greyish pubescence ; length 4 to 5 

 mm. Central Europe ..*.... 



irritans variety 

 weisii. 



irritans variety 

 rufifrons. 



irritans variety 

 meridonialis. 



0. First posterior cell narrow at the summit ; frons of male rather 

 broad, the central stripe as broad as the eye ; legs almost 

 entirely pale. Length T8 to 2'8 mm. Ethiopian species . minuta. 

 First posterior cell open ; frons of male straighter, central 

 band as broad as the eye ; legs blackish. Length 2'5 to 

 3'5 mm. From Central Europe ...... titillans. 



Lyperosia irritans, L. A large dark grey to yellowish grey species. 

 Frons of male about one-seventh total width of head ; frons of female 

 about one-half total width of head. Thorax with four somewhat 

 ill-defined dark bands, the outer pair not reaching the anterior margin. 

 Abdomen with a dorsal longitudinal median stripe on second segment, 

 elsewhere dark grey. Palpi flat and spatulate at tips. First posterior 

 cell narrowly open. 



This species is found throughout Europe and in America, where it is 

 said to have been introduced about the year 1886 ; it soon spread all over 

 the United States and the greater part of Canada. It was first noticed 

 as a serious pest in the vicinity of Philadelphia ; probably the fly was 

 first landed at this port. 



Lyperosia minuta, Bezzi. A very small dark grey to brownish yellow 

 species. Frons in male extremely narrow ; in female one-quarter total 

 width of head. Thorax dark, grey to yellowish brown, with two dark 

 brown lateral stripes, one on either side of a broad grey central band. 

 Abdomen dark grey to olivaceous grey, without any distinct markings, 

 First longitudinal vein ending opposite the small cross-vein ; first posterior 



