8 BULLETIN 812, U. S. DEPARTMENT OF AGRICULTURE. 
and is almost free from pubescence. The 13 body segments are at 
times quite prominent. 
PUPA. 
The pupa (PL I, C) measures 1.8 mm. long. It is at first white, 
later the eyes and ocelli are brown, and before becoming adult the 
pupa turns black. All appendages are folded close to the body, and a 
thin pupal skin covers the insect in this stage of its development. 
ADULT. 
The adult (PL I, A) of B. funebris is a very small black insect 
measuring about 2 mm. in length. Frequently thousands are seen 
flying over the horses and mower when the alfalfa seed crop is being 
harvested. They also collect in great swarms on the shady sides of 
alfalfa seed stacks, from which these insects emerge. Farmers fre- 
quently mistake the adults of this species for gnats, which are about 
the same size and are frequently very troublesome at the time when 
the chalcis-fly is most abundant. 
SEASONAL HISTORY. 
EARLY DEVELOPMENT. 
The first development of the chalcis-fly may be found in February 
and March throughout the Southwest, when the hibernating larvae 
begin to transform to the pupal stage. Spring temperatures and 
moisture conditions determine the time of this transformation. In 
colder climates it is much later, and under desert conditions the 
larval stage may be prolonged indefinitely. 
FIRST APPEARANCE OF ADULTS. 
The first adults appear in the spring, about four or five weeks after 
warm weather has set in. It is probable that in southern California 
adults may be active in small numbers throughout the entire winter. 
Adults of B. funebris were taken in the fields in the San Fernando 
Valley, Calif., as early as March 3, but they usually do not appear 
in large numbers until about April. At Yuma, Ariz., they make 
their appearance in March, and the first seed pods, which usually 
develop along the check ridges, become infested by the middle of 
April. On April 17 green pods were taken at the edge of a field at 
Yuma, and upon careful examination, 8 seeds showed very small 
larvae, 5 showed half-grown larvae, 15 showed full-grown larvae, and 
20 showed B. funebris pupae. E. G. Kelly observed adults of B. fune- 
bris in the field at Wellington, Kans., as early as April 21. H. T. 
Osborn reared them in out-of-door breeding cages in the same 
locality as early as April 17. In the valleys of central California 
the adults of B. funebris become active in April and oviposit into the 
seed pods of bur clover (Medicago hispida), which forms seed pods 
much earlier than alfalfa. 
