lps BULLETIN 4388, U. S. DEPARTMENT OF AGRICULTURE. 
Thus the maximum larval life was 37 and the minimum 26 days. 
The average is found to be 31.6 days. In this experiment the larve 
were kept in glass vials, but in the experiment of which the results 
are given in Table V the larve were allowed to remain on the tree 
until a day or two before they went to the soil, a small numbered 
cloth tag attached to each leaf permitting accurate observation on 
each larva. The observations recorded in Table V are, therefore, 
more normal than those indicated in Table IV. 
TABLE V.—Larval stages of the pear leaf-worm, Walnut Creek, Cal., 1913. 
Date of— Length of instars in days. 
No. Total. 
pinning 
Hatching.| Molt1. | Molt 2. eacnan 1 2 3 4 
bef Ape S137) capes t9 Apr. 24 2 6 5 4 4 19 
2 0.2575 Apr. 20 (0) 3 7 4 4 5 20 
3 dos. /22-dor (5 CG ae seal (apres C5 ee Al ae NG Co 7 4 4 5 20 
4 Gozs-— Apr. 21 dort 4 8 3 4 6 21 
5 AG Real Beeline do 5 8 3 4 7 22 
6A kdors=: Apr. 19 d@a- 25. 1 6 5 (?) 7 18 
7 ed Queeze Apr. 20 3 7 CAG?) 7 20 
8 | Apr: 14 Apr! 19") Apr. 23-})\ :(?).4. |.2.do..--. 5 AM G2) Ae) 19 
9 rdOn.see Apr. 20 O:5.2 4 6 3 3 8 20 
10 Gloves dove |eed oss 353 3 6 3 6 4 19 
11 Sedo aeet Apr 2h | Apr. 2 = 7 3 3 7 20 
12 eae Ose S| xd oueass 1 3 tf 3 4 5 19 
13 “dos: E540 ae ee do 4 u = 4 6 20 
14 | Apr. 15 | Apr. 20 (3 Co eee 2 ef 4 (2) slinG2) 19 
15 dos =2:2 Apr. 21 Gore. 7 6 3 6 7 22 
16 | Apr. 16 | Apr. 20+} Apr. 23 4 3 2) etwsws|taeseees 
17 jupeeees ed ne Apr. 24 2h ake 4 Fel ee 17 
18 dol: POG. PPAR DOR aaa 4 6 2 4 6 18 
19 douse pad ous sal eA pra 25 5 6 3 2 8 19 
20 dos=- 22 Ad Ost= as | ad Ones 9 6 3 5 9 23 
ZO pre ae Ones do 5 3 D PE al eee 
22 HdOs-<.2 JADE: (23 do 6 6 2 3 8 19 
| Bink Sedigwe.t Race do 61 6 2 5 6 19 
24 ud O2esel2 We OE esa Apr. 26 8 6 3 6 6 21 
25) Pe Apretoyiss -OOrsc= = Apr. 25 5 5 2 5 5 17 
26 ido 22 Or. Obs hace 6 5 2 5 6 18 
27 docezes BAG (Oe do 8 5 2 5 8 20 
28 Goes dole. Apr. 26 9 5 3 3 10 21 
29 dor Apr. 24 do 8 6 2 3 9 20 
30:7 |} Apr 5.09 sl. dos: dOsgas: /-iwiy PO 2 7 ae ae ee es 
31 RAGE a Geae Gorse 7 5 2 6 5 18 
32 daz=-22 -~dOr ass Apr. 28 12 5 4 4 10 23 
33 | Apr. 20 |...do.....] Apr. 26 8| 4 2 2 te 18 
34 Mosse Oz 222, Apr. 28 4 4 Canes Jona ones 
Boe PLA DES Zit ee dors PAE. 27 8 3 3 5 6 17 
36 One utd Owe Queene: 10 3 3 6 7 19 
37 dosi23 ~do:-222) 1Aipr: 98 9 3 4 3 8 18 
38 doz EMGOLs ce 4|son Oss al Mickyia 4 ee eG Oneeer 3 4 6 5 18 
39 do.s.22 Apres, 25))) vApre 294k do es edore: 4 4 5 5 18 
40 dos 0024) Mayne: 13 = 6 5 7 22 
AL | Apr y22 Ie eGorssas Apr. 29 8 3 4 3: 6 16 
42 do:-:-4| Apr. 26 ay 2 14 4 6 4 8 22 
43°) | cApE.$23 e+ dosi=--}22d0 12 3 6 4 6 19 
tt Ou <do-228 Wiis GA le eG ee eal AO Geese 3 7 3 6 19 
45 dots Apr. 30| May 4 if iney 4 5 5 21 
46 | Apr. 25| May 1] May 6 16 6 5 4 6 21 
47 | May 7| May 14| May 17 ST 2 3 5 5 20 
Out of the 47 individuals recorded in Table V, it will be noticed 
that 4 died after completing their third molt. These 4 were full 
grown and died from their inability to spin cocoons, and it 
appears that the larva, after it is ready to enter its quiescent stage, 
can not live exposed to the atmosphere. For the experiment in 
