SARCOPHAGA AXD ALLIES 99 



Na. 39. Sarcophaga davidsoni Coq. 



Coquillett, Insect Life, v. 24, 1892. 



Davidson, ibid., vi, 268, 1893, notes on parasitism. 



INIale, Front of medimii width, .195 of head 

 (average of three, — .190, .193, .201) ; middle stripe 

 fully three times as wide as one side at the narrowest; 

 parafrontal and parafacial silvery, the latter with the 

 usual row of hairs, coarse below; frontals 10, the lower 

 sharply diverging, as low as first third of the second 

 antenna! joint; antenna blackish, third joint less than 

 twice as long as the second, but reaching three-fourths 

 of the distance to the vibrissa?, the latter just above 

 the oral margin ; arista long-plumose for over half its 

 length; palpi and proboscis black, ordinary; bucca 

 one-fourth the eyeheight; back, of head with three 

 rows of black hairs, the pale beard scanty; outer ver- 

 tical bristle not differentiated. 



Thorax blackish, from behind appearing gray 

 with three black stripes ; 3 ps dc ; 3 stpl ; 2 large pairs 

 of ant acr; prescutellar rather large; scutellum with 

 two large marginal, one smallish subapical, and one 

 rather long apical pair. 



Abdomen black, from behind showing three 

 changeable black stripes on silvery pollinose ground; 

 the middle stripe rather constant; second segment 

 with more or less of a row of depressed large hairs at 

 margin, sometimes simulating bristles ; third segment 

 with a row of 12 erect stout bristles, fourth with a row 

 of about twenty. 



Hypopygium minute; first segment subopacpie, 

 with some small bristles at tip; second shining black, 

 with coarse erect hairs; forceps short, stout, straight, 

 black, with a terminal tooth almost on inner edge; 

 accessory plate oval ; both claspers much alike, taper- 

 ing, with curved tips ; penis with distinct swollen basal 

 segment, distal one black, shining behind, almost egg- 

 shaped, in front v/ith a pair of yellow protruding 

 points and a pair of flat black processes; fifth sternite 

 V-shaped, tlie inner edge fringed with black hairs. 



