ees 
= POS OO FI Fae 
J cca . - 
New YorK AGRICULTURAL EXPERIMENT STATION. 299 
tion between sex and size of larvee, but later developments of 
the specimens under observation showed a small percentage of 
males. Hence the facts recorded for the female larvae apply also 
to the males. ; 
PERIOD OF ACTIVITY. mie 
Duration.—This period includes the time from birth until the 
larva settles down. Its duration is influenced greatly by tem- 
perature, as will be seen by comparing the following table, which 
gives the record of larve kept in the inséctary and laboratory at 
temperatures of from 70° to 76° F., with the records of larvie 
kept in rooms at lower temperatures, on page 811. 
TABLE I.—LENGTH OF ACTIVE PERIOD OF SAN JOSE SCALE LARVZ IN 
INSECTARY AND LABORATORY. 
Number of pate of Date transferred 
ee ater to apple. Settled. Remarks. 
20 Sept. 1 Sept. 2 28 hrs. Insectary. 
150 “ o Chance: | 17 to. 28 ** One Jarva of this lot 
was active fur 48 hrs. 
20 sé 9 6/0 18 
3 écé 12 ¢é 13 18 “cr 
10 ets NB Oct. 6 2% “6 
4 ss 6 24) Not transferred 2 in A e - My 
280 Sept. 8 Sept. 9 Barts Laboratory. 
120 $6 9 bf oat 10) 2eF As 
90 “10 ers UD De ate 
50 ‘616 £65) by De. 484 
The total number of larve recorded in this table is 747. None 
of them settled in less than 123 hours, while a number remained 
active for from 36 to 48 hours, making the average number 27.7 
hours, or a little over one day. 
The larvee probably remain inactive for a short time after birth. 
To secure data on this point the scales were removed on Sept. 
25 from three adult females and on Oct. 8, from three more. 
Up to Dec. 18 the six gave birth to 263 larve, 20 of which 
were born enclosed in the amniotic sack. Until the sack was 
ruptured they appeared as minute, oval, light-yellow bodies. 
Most of the imprisoned larvee did not succeed in freeing them- 
selves, but those that successfully ruptured the sack escaped in 
