INSECTS AND OTHER ANIMAL Pegsts INJuRIOoUS TO FIELD BEANS 1007 
The larva 
The larva (Plate LXIX, 7) is dirty white in color, appearing darker where 
the contents of the alimentary canal show thru the body. The largest diam- 
eter is at a point about two-thirds of the distance to the caudal end. The 
head is pale yellow, with darker markings on the lateral aspect near the 
lower side. The body is much wrinkled and ‘s covered with many setae. 
On the caudal end there is a prominent erect tubercle bearing two pairs 
of prominent spines, and on the apex a tuft of fine hairs. An anal proleg 
is present. This description is from one specimen, 5.5 millimeters in 
length and probably nearly mature. 
The adult 
The adult (Plate LX XI, 8) is described by Blatchley (1910) as follows: 
Resembles hudsonius very closely. Usually a little broader and less shining, the head 
reddish or reddish-yellow; antennae and legs mostly pale. Thorax more distinctly and 
elytra less coarsely punctate. Males in both species with the last ventral segment notched 
each side, the middle lobe with a deeply impressed triangwar median line. JTength 3.5- 
4.5 mm. 
LIFE HISTORY AND HABITS 
The egg 
Immature eggs of Systena frontalis were found in dissected females on 
July 15, 1919. A few mature eggs were found in insects opened on August 
5, and many were found in those dissected on August 18. From this 
time until September 15, eggs were found in beetles that were opened. 
Eggs deposited in the cages were found after August 6. In 1920 the 
insects were much later in appearing. The first beetles were taken on 
July 29, and specimens containing mature eggs were scarce until Sep- 
tember 3. Most of the oviposition in the cages occurred early in Sep- 
tember. It may be said, then, that the oviposition period varies greatly 
from year to year, occurring at’ any time in August or September. 
After finding eggs in the laboratory cages, the writer searched for them 
in the field, and on September 20, 1919, a few were found around ragweed 
and lady’s-thumb After that date, eggs were frequently found on the 
soil near ragweed, and on September 5 three eggs were located near beggar- 
ticks. On September 11, eggs were found near a bean plant in a field 
where ragweed was growing among the beans, and in the same field, on 
September 15, one egg was discovered near a plant of lamb’s-quarters. 
As previously stated, the eggs of S. frontalis and those of S. taeniata are 
very similar, but the eggs of frontalis are larger and are usually deposited 
later in the season than those of taeniata. The eggs of taeniata hatch 
in the fall, while frontalis winters in the egg stage. The eggs Just mentioned 
as having been found in the fall of 1919 did not hatch that fall. 
Eggs of frontalis have been found, in the field, scattered irregularly 
about the roots of its host plants and from one-half to two inches deep. 
