2 BULLETIN 992, U. S. DEPARTMENT OF AGRICULTURE. 
condition of the nuts. It was not until an interest developed in cer- 
tain places in the East in growing the Persian or English walnut 
{Juglans regia) commercially that a demand arose for information 
regarding this pest. When the Persian walnut trees planted in the 
East began to fruit, these maggots attacked the nuts and practically 
ruined very promising crops in several localities. The injury to Per- 
sian walnuts and the fact that the eastern black walnut, one of the 
favorite food plants of the species, is becoming of increasing im- 
portance from the standpoint of nut production, have led to the in- 
vestigation described herein. The project is not yet completed, but 
the, outstanding features of the life history and habits of the insect 
are now known. Further studies of the species, particularly along 
the lines of control, are under way. 
BRIEF DESCRIPTION OF INSECT AND INJURY. 
The adult of the walnut husk-maggot is a two-winged fly about 
the size of the common house fly. The flies appear on the walnut trees 
at the time the nuts are approaching maturity and lay clusters of 
white eggs in punctures made in the husk with their sharp ovipositor 
(PL III, e) or in breaks which they may find in the husk of the nuts 
(PL II, 5, Cjd). Apparently no eggs are deposited in the nuts after 
they drop. The eggs soon hatch and the resultant maggots rapidly 
convert the green tissue of the husk into black pulp. After attain- 
ing full growth the maggots enter the ground and pupate, there 
being only one generation of the flies annually. 
SYNONYMY. 
The following data covering the synonymy of the species were fur- 
nished by Mr. B. A. Porter, of the Bureau of Entomology: 
Try pet a suavis Loew, 1862, in Monogr. Dipt. N. Amer., pt. 1, p. 75. 
Acidia suavis Loew, 1873, in Monogr. Dipt. N. Amer. pt. 3, p. 235. 
RhagoleUs suavis (Loew), 1899, in Coquillett, Jour. N. Y. Ent. Soc, 
v. 7, p. 260. 
DISTRIBUTION. 
This fly probably occurs pretty generally over the natural ranges 
of the black walnut and the butternut {Juglans cinerea) . In 1862 
Osten-Sacken 2 gave its distribution as the " Middle States." In 
1902 Babb 3 reared the fly from black walnut at Amherst, Mass. 
Washburn, 4 in 1905, listed the species among the flies of Minnesota; 
2 Loew, H. monographs of the diptera op north America (ed. by R. Osten-Sacken), 
pt. 1, p. 75. Washington, D. C. 1862. 
3 Babb/ G. F. note on rhagoletis suavis lw., with a description of the larva 
and puparium. In Ent. News, v. 13„ no. 8, p. 242. 1902. 
4 Washburn, F. L. diptera of Minnesota. . Minn. Agr. Exp. Sta. Bui. 93, p. 118. 
1905. 
