10 
BULLETIN 902, U. S. DEPARTMENT OF AGRICULTURE. 
The female died June 20, and the male July 31. 
The second female, which developed September 6. 1915, deposited 
193 eggs beginning March 26 and ending July 26, 1916. She died 
July 30. 
Females collected in the field and confined deposited from 27 to 
163 eggs each, indicating that many of their eggs had been deposited 
before thev were confined. 
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HABITS AND BEHAVIOR. 
It was noticed in the occurrence of this insect in Otero County, 
Colo., that the beetles could best be collected during the middle of 
the day. the time when they were most active and were out on the 
plants in larger numbers. Earlier or later in the day 
they were usually found lower down on the plants 
around the crown or in cracks in the ground. 
In order to collect them in numbers, a collecting bottle 
fixed somewhat as follows was used and found satis- 
factory: The bottoms of two small vials are broken out 
and then put end to end through the cork of the larger 
bottle (fig. 4). Upon inserting the neck of the outer 
vial over a beetle, it will invariably jump up into the 
vial. The neck is useful in that the beetle has a sup- 
port to fall on if it does not secure a footing on the 
side of the vial. Hundreds of beetles can be collected 
in a bottle of this kind with small possibilities of any 
escaping. This form of bottle has been successfully 
used for the capture of other species of flea-beetles. 
Adults mated from the middle of June to the middle 
of July, and were sufficiently abundant to do noticeable 
damage to small plants. Small radish plants were very 
much injured by the beetles eating into the stalk at 
the top or just below the surface of the ground, causing the plants 
to wilt and die. 
In rearing experiments considerable care is required to see that 
the soil, or whatever the insects are in, does not become too wet or 
too dry. If the eggs are allowed to become too wet, they do not 
hatch: if not moist enough, they shrivel and dry up. In general, eggs 
require soil that is moderately moist. 
The greatest difficulty in life-history studies was encountered in 
the larval stage. The larvae were easily killed by excessive mois- 
ture, especially when accompanied by heat. Probably several 
thousand larvae hatched but only a few lived to be adults. The 
most susceptible period is just after the larva? have hatched. The 
laboratory temperature varied from 65° to 80° F. or above, with the 
maximum temperature fqr the larvae about 70° F. This approxi- 
Fig. 4. — Device 
for collecting 
flea-beetles 
for studv. 
