OF WASHINGTON, VOLUME XVIII, 1916 171 



NOTES ON THE LARVAE OF EUXESTA NOTATA WIED. 



BY R. H. HUTCHISON, Bureau of Entomology. 



Regular periodic collections of common Diptera were made on 

 the experiment farm at Bethesda, Md. beginning about April 1, 

 1915. The adults of Euxesta notata Wied. (Ortalidae) were first 

 taken on April 30, and were seen during May, June, and July, 

 but were very rare during August and September. They were 

 never taken in or around horse stables nor accumulations of horse 

 manure. They did, however, frequent pig pens and piles of pig 

 manure nearby. These accumulations were made up largely of 

 bran and other wastes from the feed troughs, as well as of dung. 

 In fact, the bran usually exceeded the actual amount of dung, 

 and the whole mixture was very moist and in an active state of 

 fermentation Large numbers of the larvae of this species were 

 found in this bran-manure mixture during June and July. They 

 were also found in moist bran alone. One June 9 two wire basket 

 maggot traps were started, one containing about one bushel of 

 fresh horse manure, and the other an equal quantity of bran well 

 moistened. The larvae of Euxesta notata were first taken from 

 the bran trap on June 21, and continued to appear until July 1. 

 None were taken from the horse manure under the same condi- 

 tions. On August 25, a similar maggot trap experiment was 

 started using fresh horse manure on one, and bran-pig manure 

 mixture in the other. Daily collections of the larvae were made 

 until the third week in September, but no larvae of this species 

 were taken at this season of the year, although they had been 

 found breeding abundantly on the bran-manure mixture during 

 July. 



Larvae of this species selected on June 25 were put in a breed- 

 ing jar with some moist bran which had been previously exam- 

 ined to make sure that no other larvae were present. They 

 pupated during the next day or two and adults emerged between 

 July 3 and 8. I am indebted to Mr. Knab for the determination 

 of the adults. The following description of the full grown, third 

 stage maggot is made from a study of alcoholic specimens taken 

 both from bran and from the bran-manure mixture. 



Larva. (Plate Xll, fig. 1.) Average length about 7 mm. Pseudocepha- 

 lon bilobed, each lobe bearing two small papillae. Two comparatively 

 large mandibular hooks, the tips of which are visible on the exterior when 

 in repose. Each mandibular sclerite shows a small opening in its broadest 

 part near the base, and on the dorsal side is a distinct recurved spur. Two 

 hypostornal sclerites, which are long and rod like, somewhat widely sepa- 

 rated and diverging slightly posteriorly where they fit into deep incisions 

 in the lateral plates. They are more heavily chitinized at the anterior 



