May, 1914.] 
The Cheese Skipper. 
3i3 
tions longer periods occur. In fact, it is probable that larvae de¬ 
veloping late in the season pass the winter in the pupal stage. 
The imago emerges by splitting off the antero-dorsal depressed 
area. (Fig. 16.) 
The Adult. (Figs. 1, 2.) 
The specific description of Piophila Casei Linne is inaccessible 
to the writer. The following, therefor, is a redescription of the 
species based upon only a dozen or so specimens and consequently 
is not as complete as it should be. 
Male:—The dominant color is bronzy black; length to tip of 
abdomen 3.4 mm. to 3.9 mm.; to tip of wings 4.4 mm. to 4.5 mm. 
Head (Fig. 2): Palps and proboscis fuscous, covered with 
many bristles. Face, yellow to fuscous, excavated; antennae 
short, not reaching to oral margin, fuscous, non-porrect; non- 
setose arista; short bristle on second segment of antenna; cheeks, 
yellow to fuscous. Front fuscous immediately above the anten¬ 
nae to bronzy black beyond; vertical triangle smooth, shiny black, 
bears three ocelli and a pair cf ocellar bristles just posterior and 
lateral to anterior ocellus; compound eyes bare, color red. Bris¬ 
tles: vibrissae present; also several bristles on lower edge of each 
cheek; post orbital bristles present; vertical bristles 2 pair, anterior 
pair erect convergent, posterior not as erect, divergent; post¬ 
vertical bristles extend over thorax, slightly divergent; fronto- 
orbital, a series of short bristles extending from a point just 
anterior to the vertical bristles to a point above and opposite the 
base of the antennae. Row of very short bristles on ridge around 
antennal pit extending from vibrissae on the left, around base of 
antennae to the vibrissae on the right. 
Thorax: Bronzy black with 3 distinct rows of regularly 
placed short setae; Scutellum, same color, bears 2 pairs of long 
setae or bristles and several transverse parallel rows cf short setae, 
not easily observed. Sides,—same color, each bearing several 
long setae. Legs: Covered with short spines; coxa yellow to 
fuscous; femur, fuscous at joints, middle blackish-brown. An¬ 
terior leg,—tibiae, except at proximal joints, and tarsi, blackish- 
brown. Middle and hind legs,—Tibiae blackish-brown to fuscous, 
fuscous at joints, tarsi fuscous. 
Abdomen: Rectangular, sides somewhat parallel, tip blunt. 
Same color as thorax. Six visible segments, each bearing many 
short spines. 
Wings: Overlap nearly to tips when fly is at rest. Wholly 
hyaline, irridescent, auxiliary vein indistinct or closely apposed 
to the sub-costa; halteres, pale yellow. 
Female:—Same color as the male. Length to tip of abdomen 
3.9 mm to 4.1 mm; to tip of wing 5 mm. to 5.2 mm. Abdomen,— 
six visible segments, pyriform. 
