OF WASHINGTON, VOLUME XIX, 1917 loo 



after laying two or three eggs the fly would leave the pocket and 

 encircle the tree a few more times, then return and repeat the 

 above habit. The eggs were left exposed. The fly was nearly 

 two hours depositing twelve eggs. 



The egg is opaque, white, cylindrical and tapering slightly to- 

 wards each end. The surface is very faintly reticulate. It is 

 0.75 mm. in length and the diameter is equal to half the length. 



Larva (plate XVIII, fig. 1). 



This larva is a typical rat-tail type. Body elongate, elliptical, and 

 very rugose transversely. It is opaque, grayish-yellow with a little white 

 showing through. The tail is grayish-brown and darker than the body. 

 The body is completely covered with a fine, pale yellow pubescence which 

 is longer on the lateral edges. Cephalic end rounded. Caudal end tapers 

 down to the rat-tail which is cylindrical. A narrow area across the front 

 of the head, is beset with minute spines which are pale yellow at the base 

 and dark yellowish-brown at the apex. The dorsum of the first segment 

 has seven longitudinal, faintly impressed grooves, the end grooves are 

 the smaller. At the base of the second groove is a small, tubercular, chi- 

 tinous, dark brown spiracle, opening on the outside. 



The tail is very slightly larger at the base than at the apex; the sides 

 being almost parallel. On the lateral edge at the base of the tail, is a 

 tubercle with a tuft of long yellow pubescence at the apex. Just belo\v this 

 tubercle is a similar, but smaller one. On each side of the apical end of the 

 tail is a very small, transparent, colorless, cylindrical projection, terminat- 

 ing into a hair-like projection. The tail is composed of three sections; the 

 apical and middle sections are retractile in-to the basal one. The apical 

 section is somewhat chitinous, especially at the apex. 



The mouth parts (fig. a) are entirely suctorial. The buccal cavity is 

 darkened on its edges and is located just beneath the apex and between 

 two large, rounded, fleshy folds. Just above the edge of the buccal cavity 

 are the antennae; they are white and form one solid trunk at the base which 

 is liifurcate on the apical half. Each half is divided at the apex, appearing 

 like two small, yellow, chitinous thimbles. The inner one has a small 

 tubercle at the apex (fig. b). 



When disturbed, the antennae are drawn into the buccal cavity. 



Just below the buccal cavity is a pair of ampullae, the next segment 

 does not have any, the following six segments each have a pair. Kach 

 ampulla has a number of yellowish-brown bristles, hooked outward!}' on 

 the end; and are located near the apex. 



The larvae when full grown, average, in the body, 12 to 15 mm. in length 

 and 5 mm. in width, and nearly cylindrical. The tail is 5 to 6 mm. long, 1 

 mm. diameter at the base and tapering slightly towards the apex. When 

 the tail is fully extended it reaches about 19 mm. in length. 



