98 



Description — Length, 1.25 mm to 1.37 mm ; width, 0.34 mm to0.41 mm . Shape, irregular 

 oval, nearly straight along one side, convex along the other. General color, light 

 reddish "brown, lighter after hatching. General surface covered with a hexagonal, 

 epithelial-like sculpture, each cell from .027 mm to .033 nim in length hy about half 

 the width. In the unhatched egg, even in those just deposited, a long, rather nar- 

 row, ribbon-like strip is noticed along the entire length of the flattened side, rather 

 spatuloid in shape. In hatching this strip splits off, remaining attached at one end, 

 and the larva emerges from the resulting slit. 



Larva. — After the eggs hatch the larvae descend into the dang, re- 

 in aining, however, rather near the surface. 



Newly-hatched Larva.— Length, 2.45 mm , and greatest width, 0.48 mm . Color, pure 

 white. Joints of segments rather plainly marked, venter with slightly elevated ridges 

 at ends of abdominal segments, the ridges with delicate sparse rugosities. Resembles 

 in main full-grown larva. 



Full-grown Larva. — Length, 7 mm ; greatest width, 2 to 2.5 ,nm . Color, dirty white. 

 Antenna? 3-jointed, last joint pointed. Head with a lamellar or ridged structure 

 shown in figure; divided by cleft at tip; skin behind lamellar structure coarsely 

 granulated, while that of thoracic and abdominal joints is nearly smooth. Thoracic 

 stigmata pedunculate with six pedunculate orifices. Ridges on venter of abdominal 

 joints not strong, fainter than in young larva. Anal stigmata large, slightly pro- 

 truding, very dark brown, nearly round, flattened on proximal borders, slightly longer 

 than broad, 0.14 mm in length, with one central round opening, and a series of very 

 delicate marginal tufts of cilia, four tufts for each spiracle, each issuing from a cleft, 

 but none on the proximal edge. Anal segment below with a dark yellow chitinous 

 plate showing six irregular paired tubercles; the surface of the skin surrounding the 

 plate rather coarsely granulated. 



Puparium. — W-hen ready to transform the larvae evidently descend 

 from the dung into the ground below from a half to three-quarters of an 

 inch. Actual observations were made on larvae in dung in breeding- 

 cages where the soil was fine sand, affording ready entrance to the lar- 

 vte. Where the dung has been dropped upon hard ground the proba- 

 bilities are that they will not enter so deeply, and may indeed transform 

 upon the surface of the ground at the bottom of the dung. 



Description.— The puparium is from 4 mm to 4. 5 mm in length, by 2 mm to 2.5 mm in 



width, regularly ellipsoidal, the head rather more pointed ; dark brown in color. The 

 segments are plainly separated. The anal stigmata are darker in color than the rest 

 of the skin ; are slightly protruded and preserve the same shape as in the larva. The 

 central opening is still visible, as are the slight indentations of the border. The ven- 

 tral plate, noticed at the base of the anal segment of the larva is still noticeable as a 

 series of tubercular elevations. 



Duration of the preparatory Stages and consequent Num- 

 ber of annual Generations. — The first flies reared at the Depart- 

 ment issued August 7 from eggs deposited July 28. These were five or 

 six in number. August 8 four more issued from the same lot. August 

 12 six flies issued, reared from eggs laid July 31 ; August 13 two more, 

 and August 14 two more from the same lot. Delayed specimens issued 

 from this lot August 20 and 23. August 26 seven flies were reared from 

 two or three days' old dung, collected August 17. These observations 

 show the bulk of the flies during late July and August to issue from ten 

 to fifteen days from the laying of the eggs. In all cases the eggs hatched 



