94 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
LIFE CYCLE OF THE FIRST GENERATION. 
From the earliest appearing eggs in spring, about April 15, to the 
first appearing moths, June 17, gives some 63 days as the approxi- 
mate length of the life cycle of the first generation. The laboratory 
records for individuals kept in breeding cages give a life cycle of 71 
to 78 days. This, however, is based on only 12 individuals, which 
completed the cycle, and are recorded in Table VI. Careful obser- 
vation indicates the length of time of the first generation to be from 
60 to 70 days. 
THE SECOND GENERATION. 
SECOND-BROOD EGGS. 
Time of oviposition—A number of moths which emerged at the 
Jaboratory in late June and early July were put in rearing cages con- 
taining small branches of fruit and leaves and also fruit juices and 
sugar for food. The first eggs were deposited July 3. Some of the 
moths died before depositing eggs. On June 28, 1909, while looking 
after spraying operations in the field, frequent searches were made 
in the unsprayed block, but no eggs were found. During another 
search on July 7 among these trees many eggs were found and 5 
larvee just hatched, none of which had entered fruit, were found dur- 
ing the forenoon. Eggs were being deposited in large numbers in 
-rearing cages July 8 to 10. 
Incubation period.—The time required for incubation was less than 
half that required for the first-brood eggs. In cages this varied from 
71 to 94 days, and averaged 8} days. The weather at this time was 
usually warm throughout the day with comparatively cool nights. 
In Table VIII are recorded incubation periods for several groups of 
eggs deposited between July 3 and 29. It will be noticed that eggs 
deposited July 10, 11, 26, and 28 required shorter time for incubation 
than others. Both of these periods were followed by 3 to 4 days of 
very warm weather. 
Taste VIII.—Ineubation periods of second-brood eggs, Walnut Creek, Cal., 1909. 
| | | 
Yate of— Date of— 
pee | Period | ee | ; Fetige 
Observa- | Number | + of in- serva- | Number of in- 
é | ~ | gg dep-| Hatch- : é ~ | Egg dep-| Hatch- | ~ 
tion No. | of eggs. eran ing of cube: | tion No. of eggs. | Gsition ing of cube 
| (night). | eggs. on’ (night)..| eggss, aces 
a ~—- | — — ~ a= | 
Days. | Days. 
AS ASHES aoe 3) | duly: 3) only; 12 8 45 | July 15 | July 24 8 
De ic aS | 4 6 16 9 35 16 2 8 
3 OOO a | 4 ue 16 8 || 20 17 26 8 
yee mae 10 | 7 16 8 || 12 20 29 8 
Ben a ees 15 8 17 8 || 70 24 | Aug. 2 8 
Oz seas 19 10 18 7 75 26 3 7 
(ese 15 11 19 7 60 28 5 a 
Sacre. 14 12 22 9 40 29 6 8 
Qe ee ap arsesis 11 13 23 9 9] Aug. 1 12 10 
Incubation period: Days. 
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