LIFE HISTORY AND HABITS: THE PUPA. 87 
These figures show interesting differences from the Michigan 
records. Thus, the average number of days for all larvae in soil before 
pupation is 16.08, as against 12.03 in the Michigan records. The 
average length of the pupal stage at Barnesville, 9.18 days, is notably 
less than shown for Michigan, namely, 14.12 days. However, adding 
together the average larval and pupal stages for each locality shows 
these sums to differ by only 1 day, the lengthening of the larval stage 
in the ground in Georgia being offset by a shorter period in the pupal 
condition. In the Georgia records the average time spent by the 
adults in the ground before emerging is 5.62 days. The average 
time of the 37 individuals spent in the soil is 30.89 days. 
DEPTH OF PUPAL CELL. 
Great diversity of opinion was expressed by the earlier writers as 
to the depth to winch curculio larvae entered the soil for pupation, and 
no very accurate observations on this point seem to have been made. 
Riley states that they go below the surface from 4 to 6 inches, and 
remarks that he never found them deeper than 6 inches. Riley and 
Howard, writing in 1888, state that the larvae seldom burrow to a 
greater depth than 4 or 5 inches. Other wTiters say "a few inches," 
11 2 to 3 inches," "a short distance," and one states "15 to 36 inches." 
Prof. Crandall was perhaps the first to secure exact data on tliis 
point. In 1903 observations were made on the depth of pupae in 
ground, including 78 individuals secured under natural conditions 
under trees in orchards, 79 from bottomless soil boxes, and 22 from 
breeding cages in the laboratory — a total of 179. In 1904 data were 
obtained on 645 individuals, 24 by digging' earth under trees. 298 from 
soil boxes, and the remaining 323 from larvae pupating in the labora- 
tory. Using the records for both seasons obtained under out-of-doors 
conditions — that is, under trees or in soil boxes, sod and cultivated — 
we find that of the total 482, 336, or 69.70 per cent, pupated within 
1 inch of the surface, and 475, or 98.54 per cent, within 2 inches of 
the top of the soil. 
Prof. CrandalTs laboratory records do not show important differ- 
ences from those obtained out-of-doors. Some individuals pupated 
at a greater depth, as 8 at 3 inches, 1 at 3J inches, and 2 at 3J inches, 
as against 1 at 2^ inches, 3 at 2V inches, and 3 at 2j inches, under 
out-of-doors conditions, due perhaps to a greater dryness of the soil 
in the laboratory. 
Messrs. Girault and Rosenfeld, in Georgia, in 1906, obtained 
records on the depth of pupation of 121 larvae under natural out-of- 
doors conditions, the soil being a sandy loam. One hundred, or 
82.64 percent, pupated within 1 inch of the surface, and all. or !00 
per cent, within 2 inches. Other records on depth of pupation in the 
