148 SANITARY ENTOMOLOGY 



simple straight slits directed slightly downward but mostly toward those 

 of the opposite plate; the button is distinct (fig. 28). 



The blow-fly deposits eggs on dead animals, and also on fresh and 

 cooked meats. As such are often accessible to them in pantries, it is 

 readily seen that many larvse are swallowed by people each year; there 

 are, however, comparatively few records published, probably because the 

 polluted food causes no trouble. 



Calliphora vomitoria Linnaeus 



This larva appears to be identical with that of Calliphora erythroceph- 

 ala. There seem to be no visible characters to separate it from this 

 latter species (figs. 27 and 28). The habits are about the same. 



r 



Fio. 27. — Larva of Calliphora erythrocephala: side view of heed and prothorax. 

 (Greene.) 



Lucilia sericata Meigen 



Body rather stout, not slender in front. The head is distinctly 

 divided into two parts or lobes, with distinct papilla (figs. 31a, b). The 



^^ 



Fig. 28.— Larva of Calliphora erythrocephala: enlarged sketch of left stigmal plate. 

 These plates are one and one-quarter times their breadth apart. (Greene.) 



two great mouth hooks are well separated. The anterior spiracles are 

 provided with about eight lobes. The surface of the body is mostly 

 smooth; the sides of segments 3, 4 and 5 are bilobed; beginning with 

 segment 6 there is a basal ring girdle, roughened. These girdles on seg- 

 ments 6 to 9 are widened on the middle of the under side of the larva; 

 the sides are also swollen, but not plainly bilobed, except those near 

 the tip. The under sides of the segments are transversely divided by a 

 line or furrow in the middle. The last segment is short, the stigmal 

 field occupying most of the tip. The stigmal field has a slightly de- 

 pressed, upper lip with three sharp tubercles on each side, the interme- 

 diate one hardly smaller than the others ; and a lower lip with two large, 



