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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
Table II—Incubation Period 
No. Eggs 
Minimum 
Maximum 
Average 
Date 
Hatching 
Days 
Days 
Days 
1916 
51 
9 
23 
13 
1917 
56 
13 
25 
18 
shell of the egg. When hatched, the grub is about 2 mm. long and, 
except for the mandibles, is entirely white. In a few hours the entire 
head begins to darken until it has assumed its final brownish color. 
The grubs when full grown are about 23 mm. long and 6 mm. through 
their widest part, and are creamy white in color. In their charac¬ 
teristic doubled-over position, they appear about one-half as long or 
about 12 mm. 
The grubs of this genus are distinguished from those of Lachnos- 
terna by the absence of the median longitudinal double row of mesad 
pointing spines on the last abdominal segment of Lachnosterna and 
by a transverse anal slit which in Lachnosterna is Y-shaped. Accord¬ 
ing to Davis (1916, p. 266) the Cyclocephala grubs resemble those of 
Cotalpa, with which they are more apt to be confused. 
As the time of pupation approaches, the grubs shed the meconial 
mass in their alimentary tract and appear to shrivel up somewhat, 
cease feeding, and become generally inactive, forming the prepupal 
stage. Table III gives the length of the complete larval stage as it 
occurs in Kansas. 
Table III —Development op Grubs from Hatching to Pupation 
Serial 
No. 
Hatched 
Became 
Prepupa 
Pupated 
Length of 
Prepupal Stage 
(days) 
Complete Time 
of development 
(days) 
1916 
1917 
1917 
1895 
July 15 
June 23 
June 30 
7 
350 
1896 
July 15 
June 26 
July 1 
5 
351 
1898 
July 16 
July 6 
July 12 
6 
361 
1899 
July 16 
June 28 
July 5 
7 
354 
1902 
July 16 
June 27 
July 5 
8 
354 
1903 
July 17 
Jnly 10 
July 16 
6 
364 
2246 
July 22 
July 5 
July 11 
6 
354 
2247 
July 22 
June 28 
July 5 
7 
348 
2356 
July 23 
June 26 
July -5 
9 
347 
2361 
July 24 
June 26 
July 1 
5 
342 
2945 
July 27 
June 23 
July 1 
8 
339 
3036 
Aug. 1 
July 1 
July 8 
7 
341 
3038 
Aug. 1 
June 26 
July 5 
9 
338 
3040 
Aug. 2 
June 30 
July 7 
7 
339 
3041 
Aug. 2 
June 26 
July 3 
7 
335 
3042 
Aug. 2 
July 7 
July 13 
6 
345 
3083 
Aug. 2 
July 9 
July 16 
7 
348 
Average 6 
347 
The average time of complete development for 17 individuals was 
347 days, with a minimum of 335 days and a maximum of 364 days. 
The prepupal stage has an average length of 6 days, with a minimum 
