JOURNAL OF AGRKEFURAUESEARCH 
DEPARTMENT OF AGRICULTURE 
Vol. VII Washington, D. C., October 23,1916 No. 4 
LIFE HISTORY OF HABROCYTUS MEDICAGINIS, A 
RECENTLY DESCRIBED PARASITE OF THE CHALCIS 
FLY IN ALFALFA SEED 
By Theodore D. Urbahns, 
Entomological Assistant , Cereal and Forage Insect Investigations , 
Bureau of Entomology 
INTRODUCTION 
The following account of Habrocytus medicaginis Gahan is the result of 
observations concerning its parasitism upon Bruchophagus funebris How. 
inhabiting alfalfa seed (. Medicago sativa). The observations were begun 
in the fall of 1912 and continued into the year 1915. The field observa¬ 
tions and collections extended over several of the States west of the 
Rocky Mountains. The laboratory studies were conducted at Glendale 
and Pasadena, Cal. 
DISCOVERY OF THE PARASITE 
This new hymenopterous parasite, H. medicaginis , was first found by 
the writer on September 28, 1912. Several specimens had emerged from 
alfalfa seeds infested by B. funebris collected at Yuma, Ariz., on August 
30. Adults of the parasite continued to emerge from the seeds until 
October 15 of the same year. 
The parasite was again reared on November 4, 1912, from infested 
alfalfa seeds taken at Chino, Cal., on September 24; from this lot of 
seeds individuals continued to emerge until July 12, 1913. Additional 
alfalfa seeds collected at Tulare, Cal., on October 1, 1912, yielded this 
species at different times between June 11, 1913, and April 9, 1914. 
Alfalfa seeds dissected on March 6, 1913, at Glendale, Cal., showed 
larvae of this species feeding upon the dead larvae of B. funebris . Some 
of the parasite larvae were reared to the adult stage as early as April 22. 
The writer made many collections of alfalfa seeds throughout the 
different alfalfa seed-growing districts between the Rocky Mountains 
and the Pacific coast during the seasons of 1913 and 1914. Prom these 
seeds adults of H . medicaginis emerged as follows: Dos Palos, Cal., 
October 11, 1913; Stockton, Cal., June 16, 1914; Brawley, Cal., June 
( 147 ) 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
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Vol. VII, No. 4 
Oct. 23, 1916 
K — 44 
