THE CODLING MOTH ON PEARS IN CALIFORNIA, 19 
Walnut Creek, three eggs were found on foliage in the field, and on 
May 2 eggs were numerous throughout the valley. At Suisun, Cal., 
larvee were hatching April 29, and-on May 3 young larve were quite 
numerous in some of the warmer sections of Suisun Valley, indicating 
that eggs were deposited in numbers some two to three weeks before, 
that is, from the 12th to the 20th of April. 
Incubation period.—One noticeable difference between the life his- 
tory of the codling moth in California and in the country east of the 
. Rocky Mountainsis the increased length of time required for incubation 
of the first-brood eggs. As a rule there is considerable cool weather, 
especially at night, during the months of April and May. This was 
especially noticeable in the vicinity of Walnut Creek in 1909. The 
time required for incubation varied from 17 to 22 days, averaging 
20.05 days for the individuals under observation. The individual 
record for 56 eggs, deposited from May 8 to 11, are given in Table VI. 
In the spring of 1910 the period of incubation was not observed 
individually for many eggs, but all indications were that the incuba- 
tion period varied from a minimum of 15 days to a maximum of over 
30 days, with the majority requiring about 25 days. 
TaBLe VI.—Life cycle of the first generation, Walnut Creek, Cal., 1909. 
Date of— | Days for— 
Individ- | “ = See hae 
ual No. | Egg dep- F arva = mer- as eed- |Making Total 
osition tcl leaving eee gence of Elie ing of | of co- pape life 
(night). 8 fruit. r moths. larva. | coon. | P “| eycle 
| 
A neSeeD ape May 3 May cal soSzactosdipocseaygoclesscoeszoc fi Sp enspUR teases ca|eancesaa |Jeeoccos 
eee 8 | OF) eee ke Eas a ge aaa DO Bele e es cee (oe, ay el pe 
Bae et 8 | Sa Si el ao ietroet ee | septa eee COW Re Beeeel oeene sal oeeaadl es teem 
eae ae 8 7h tA A Sl (Re ae SR ee ae | 7H eh be te | Se Pe ae Sie oe 
(OSS eee ae 8 28 | June 24) July 1) July 24 20 27 7 23 77 
Users settee 8 28 Po tare eae gas [eee ee 20 CON EA Seic ces aes Send betoeey f 
Bete tos.cie 8 | 28 29 | 4 25 20 32 2 78 
QM 4.2: 8 29 29 | 5 23 21 | 31 6 18 76 
UO aaa 8 28) |3 222 =) Veratate Samet elope a acesciel 7A ees ons SSE Cees BSR nna iaaaee SD 
ie eee 8 29 24 | 2 18 21 26 8 16 71 
er ioe Ss 8 29 DN cai nore aoe Pee et eee 21 | 7 tal eee Sel aE! |i ac See 
GS aeeReaee 8 29 29 Neate 2,2 a eats Aolemelad 21 | 3 Ee ese oe Ss Beer eens Fn 
jaa a 8 Fi eRe th sets ee meee iu bo ers Ree ea paps reek 7 > 
iT a Se 8 28 | DANES eels (eet 20 D7 |e2esn tle est Acs lad cede 
UGS. ey 8 30 | PEO | Ava S10) eeeo soe se 22 25 Gh liseetenellecomeen 
il ee 8 30 23 | SORE ia 22 24 if || Seetneee | Nero 
1 eae Cee 8 
1 Sees 8 
2, ae 8 
Pile S28 co 2 8 
Ty) Se eee epee 9 
28 Se oeeoe 9 
7: oe 9 
Pee eae ss 9 
ieee eee 9 
ieee ee 9 
Asse ee ae 9 
Pe eae 9 
De a aa 9 
Blige 2222. 9 
SS eee 9 
Spee eects 9 
ae ete) 9 
OOeeaes oe 9 
5 oe ne 9 
