16 BULLETIN 438, U. S. DEPARTMENT OF AGRICULTURE. 
Thus 88.7 per cent of all the cocoons were formed less than 1 inch 
below the surface of the soil. This approximates the percentages 
found at this depth in California. 
Tables XI, XII, and XIII indicate the period spent in the cocoon 
in California: 
TABLE XI.—Cocoon records of the pear leaf-worm, 1911-12. 
Date of spin- | Date of adult 
Place. ning cocoon. emergence. 
SanwWosei@alesacnies ye May 13,1911 | Mar. 25,1912 
(DOT CoNosasccae see May 16, 1911 | Mar. 18,1912 
IDO 825s 5 Rice se | ese do... : Do. 
Red Sora Cave 2.75.2.) Apr: 25, 1911 | Mar. 4,1912 
eae eee Apr. 26, 1911 | Mar. 10,1912 
do Do. 
TasBLE XII.—Cocoon records of the pear leaf-worm, 1912-18. 
Date of spin- | Date of adult 
Place. | ning cocoon. emergence. 
San Jose, Calis. 2/222! May 9,1912| Mar. 23,1913 
May 10, 1912 | Mar. 30,1913 
May 11,1912 | Mar. 28, 1913 
sates do. -| Mar. 8, 1913 
May 12, 1912 | Mar. 31,1913 
May 15,1912| Mar. 7,1913 
TasLEeE XIII.—Cocoon records of the pear leaf-worm, Walnut Creek, Cal., 1913-14. 
i 
Date of Date of Date of WEES Date of Date of Date of Date of 
spinning adult spinning adult pinning adult spinning adult 
cocoon, pence: cocoon, eee cocoon, Banc | cocoon, sauce 
oy av~S } ? 
LD ieee yes 1914. | ARLE SSA iia 
May 2{| Mar. 18 || May 4] Mar. 18|| May 7] Mar. 20|| May 9| Mar. 20 
May 3] Mar. 14 Ous AG ORE May Mar. 19 Co Ko eee (0) 
Dose 22 Mar. 15 dove Mar. 19 ||.--do.-...- Mar. 20 || May 12 Do 
Dor o2 Mar. 18 |} May 5] Mar. 15 ||..-do....-. Mar. 21 Gorse Mar. 25 
Dow Mar. 19 do: 24 Mar. 20 || kdos ee Mar. 29 || May 138] Mar. 18 
Dose s|a 38 Goze. May 6] Mar. 18 || May 9] Mar. 16 Go=tees Mar. 19 
Dost. Mar. 20 des Mart 20 4)222d02- 35: Mar. 18 || May 14} Mar. 31 
May 4/| Mar. 15 |} May 7| Mar. 18 dose. Mar. 19 || May 16 | Mar. 22 
Douce h Mar. 18 
The average time spent underground in a cocoon, first as larva and 
secondly as pupa, is about 10 months and 10 days. Table XIV 
summarizes the adult emergence recorded in Table XIII. 
TABLE XIV.—Summary of Table XIII, adult emergence of the pear leaf-worm, 1914. 
Number Number 
of adults Date. of adults Date. 
issuing. issuing. 
1 Mar. 14 if Mar. 21 
3 Mar. 15 1 Mar. 22 
1 Mar. 16 1 Mar. 25 
8 Mar. 18 1 Mar. 29 
8 | Mar. 19 1 Mar. a3t 
8 | Mar. 20 
