ART. 9 TWO-WINGED FLIES OF TRIBE MILTOGEAMMINI ALLEN 29 



direct parasitism. At the termination of the feeding period of the 

 maggots, two Uving nymphs remained still untouched, so it appears 

 in this instance that the competition for food did not furnish the urge 

 for the elimination of the host. So far as could be determined, the 

 somewhat slower growing wasp grub with its more delicately adjusted 

 parasitic life, was overwhelmed in the tumultuous activity of the fly 

 maggots, to whom its death was merely incidental. The maggots, 

 reared during July, developed very rapidly, far outstripping the grubs 

 of Bicyrtes reared in the laboratory under the same conditions. Mag- 

 gots removed with the nest on July 26, pupated on the 30th, indicating 

 a larval period of approximately four days. In Columbus, Ohio, one 

 specimen was reared from a puparium recovered from damp sand 

 near the underground cells of Bemhix spinolae, indicating that the 

 mature maggots at the termination of the feeding period burrow in 

 the soil that surrounds the nest to pupate. The pupal duration of 

 two individuals was respectively seven and eight days. Possessing 

 the power to complete a life cycle in about two weeks, it is highly 

 probable that generations succeed each other rapidly during the 

 favorable seasons. However, the development of but one generation 

 has been under observation and the seasonal cycle is unknown, 



SENOTAINIA LITORALIS Allen 



Senotainia litoralis Ali^en, Occ. Papers Bost. Soc. Nat. Hist., vol. 5, p. 90, 

 1924 



Type.— Male, Cat. No. 27232, U.S.N.M., from Moss Point, 

 Mississippi. 



This species may be readily separated from trilineata, from which 

 it differs in having the frontal rows at their middle separated by a 

 distance less than width of either parafrontal and in having but two 

 weak postsutural dorsocentral bristles. From vigilans, it is dis- 

 tinguished by lack of red on the abdomen and usually in the posses- 

 sion of two proclinate orbital bristles. Male specimens differ in 

 having the sides of the fifth sternite roundly angular at the apex and 

 not lobiform, and the hind femur without villosity on the inner 

 proximal surface. The male genitalia arc illustrated (pi. 2, fig. 10). 



In the one female dissected, the reproductive apparatus (pi. 4, 

 fig. 25) was found to differ from the typical in several respects. 

 Whether these variations are specific or merely individual w^as not 

 determined. The uterine pouch was balloon-shaped and not chor- 

 date; the ovules were filled with ova of all stages of development 

 while at the same time the uterine pouch carried several well devel- 

 oped larvae. Only two spermathecae were present, and these were 

 united for somewhat more than the basal lialf. One of the accessory 

 glands was very much reduced in size, the other normal, with the 

 duct less than one-tenth the length of the ofland. 



