Jan. 5, 1924 
The A rgus Tortoise Beetle 
47 
ally cool spring. The first egg masses were obtained May 23. The 
first new generation develops during the last week of June and through¬ 
out July, with the temperature 6o° to ioo° F,, averaging 75 0 . 
May 17, 1920, adults were collected on the western edge of the truck 
farm at Arlington, Va., and on the far side of a large sewer pipe which 
had undoubtedly attracted them, as it conserved considerable heat. 
Nearly all of these beetles were on the west side, morning-glory plants 
which were numerous on the east side harboring only one specimen. 
The beetles hibernated on the more protected side and mostly together, 
since all specimens were found in two small areas, representing colonies, 
quite close to each other. Additional evidence of the eminently gre¬ 
garious habit of this species was afforded the following morning by 
examination of the jar in which these beetles were placed overnight. 
At first glance it was thought that some had escaped, but close exami¬ 
nation showed that they were closely huddled together in the folds of the 
small leaves. 
Larvae obtained in late August transformed to pupae September 1, 
and the adults emerged September 10, which gives 9 days for the pupal 
period during moderately cool weather, with the temperature ranging 
from 70° to 82° F., and averaging 74 0 F. 
The first pupa was observed on June 23. The larval period is about 
three weeks in cool summer weather, and the pupal period for the same 
temperature is about nine days. The fact that the species has only an 
exceptional second generation in the District of Columbia tends to 
show that it is single-brooded in the North and fully double-brooded in 
the Southern States. 
The adults issue at any time during the day, and the coloring begins 
at the head and legs, the dots on the prothorax appearing some time 
before those on the elytra. When first emerged the beetles are bright 
yellow, afterwards changing to a darker yellow and finally to yellowish 
red or dark brick red. For full coloring the insect requires at least two, 
and probably three days. 
The beetles cling most tenaciously to foliage or to objects in rearing 
cages, unless they drop down to “play 'possum/' and evidently for that 
reason do not very often find their way into the collecting net, most 
individuals having been collected on their food plants and elsewhere, 
where attention was attracted to them because of their conspicuous 
coloring. 
The first eggs obtained during 1920 were laid during the last week of 
May, beginning May 22, and the first larvae were noticed June 10. Eggs 
that were laid June 4 and were isolated, hatched June 14, 10 days later. 
From this lot the larvae began to transform to pupae July 3 and the adults 
began issuing July 10. The pupae began to transform to beetles at the 
same date in different jars kept under different atmospheric conditions. 
The foregoing data furnish the following as an approximate average 
life cycle from egg to adult for the District of Columbia and vicinity: 
PERIODS OP THE STAGES OP CHEEYMORPHA CASSIDEA PAB. 
Egg period: r>ays 
June 1 to June n. . . 10 
June 4 to June 14.. 10 
Larval period: June 14 to July 3... 19 
Pupal period: July 3 to July 10, September 1 to 10. 7 to 9 
Total from egg to adult. 36 
