- 3 - 
underwings are present but very rudimentary and vary greatly in size with 
the individual beetles. The elytra are fused together, and the adults are 
incapable of flight. The newly formed adults are equipped with a pair of 
cusps (fig. 1, F) , one attached to the anterior face of each mandible. These 
cusps are used for cutting their way through and out of the soil. Shortly 
after emergence the adults lose these cusps, sometimes one at a time or both 
at once, usually after they have fed more or less extensively upon plant 
foliage. After these cusps are lost there remains a scar on the anterior 
face of each mandible indicating the place from which the appendage has 
fallen. 
E mergence of the adults . — In 1938 information on the dates and rate 
of emergence was obtained by the use of 138 cages, which covered 1 square 
yard each. A portion of these cages were located near Svea, Fla., and the 
remainder near Lockhart, Ala. Daily rainfall records were kept in each 
locality. The first adult was observed in the field -on May 25, but it is 
highly probable that a few emerged as much as a week prior to this date, as 
a few pupae were found on May 6. 
The emergence as determined by means of these cages extended from 
June 5 to August 15. The peak of emergence was reached on different dates 
in the two localities. At Svea the peak was during the period June 21-30, 
when 44.3 percent of the total emergence occurred. At Lockhart the peak 
was reached during the period July 11-20, when 53 percent of the total 
emergence occurred. A study of the combined records of emergence for the 
two localities shows that 7.8 percent of the total occurred prior to June 
21, 87 percent occurred during the 30-day period June 21 to July 20, and 
only 5.2 percent occurred during the remainder of the season. 
The length of time this insect remains in the pupal cell after trans- 
formation to the adult depends upon the amount of moisture in the soil. 
When the upper soil becomes dry only a small number of the beetles trans- 
forming to adults cut their way out; most of them remain in the soil until 
rain occurs. Under laboratory conditions beetles have remained in their 
pupal cells within the soil for periods ranging from 8 to 80 days, emerging 
whenever moisture was applied. 
The emergence in 1938 at Svea and Lockhart reached the peak im- 
mediately following precipitation. At Svea the daily emergence in the cages 
from June 5 to June 20 never exceeded 39 beetles. A total of 1.43 inches of 
rain fell on June 19-21. The daily emergence increased from 6 on June 
19 to 84 on June 21 and to 180 on June 22. During the 4-day period June 
21-24, or immediately following this rain, a total of 424 beetles emerged. 
This was 19.2 percent of the total emergence. From June 29 to July 10 
only one light shower occurred, this being 0.07 inch on July 6. A rain of 
1.04 inches fell on July 11. Prior to this rain the emergence had slowed 
down, only 16 beetles emerging on July 10 and 3 on July 11. The emergence 
on July 12 was 128 beetles. Following this latter rain the emergence was 
314 beetles for the 3-day period July 12-14. This constituted 14.3 percent 
of the total emergence. 
