50 THE SA:S^ JOSE OK CHIXESE SCALE. 



of May: at Amherst, Mass.. the\' were first noticed June 1^, and in 

 Arizona they are recorded as appearing in March. The larvcB are con- 

 tinuoush^ present on the trees until further hatching is prevented by 

 severe frosts. In 1891. as vre have already shown on page 289 of Vol- 

 ume VII of Insect Life, the first frosts at Washington occurred in the 

 latter part of October and the hatching of the young ceased before the 

 1st of November. October 21:, 1891. however. Doctor Howard saw 

 recently settled larvae, not more than 5 days old, at Lewisburg. Pa. In 

 1895 the October frosts were insio-nificant. and in this neio-hborhood 

 no severe frost occurred until about the 1st of December. The result 

 was that young larvi^ were found at Washington until late in Novem- 

 ber, while on twigs received from Chestertown, ]Md.. November 13 and 

 November 27, the yaung were more or less abundant. The cold spell 

 of the last week in November and the first week in December put a 

 stop to development here. This same cold spell was of very wide 

 extent. As far to the southAvest as San Antonio, Tex., the thermom- 

 eter dropped to 31^ on December 3. A similar, or even lower, tem- 

 perature was noted at New Orleans, yet on December 16 Doctor 

 Howard found newly hatched young, less than 21 hours old. upon a 

 plum tree at Audubon Park, New Orleans. 



In autumn, or when further development is stopt by cold weather, 

 hibernation is begun by scales in all stages of development, from the 

 white, minute, down-covered recently hatched young to the mature and 

 full-grown females and males. Unquestionably many young perish 

 during the winter, and normally in spring quite a percentage of the 

 smaller or half-grown scales will be found to have perished. It is 

 very probable that many females have union with the males in the fall, 

 but the majority of them are unquestionably immature, and are fertil- 

 ized in this latitude early in April by overwintered males which, as we 

 have. noted, appear nearly a month before the first young of the spring 

 brood. 



The actual rate of the production of young at difierent periods of 

 the life of the adult female has not been determined with accuracy. 

 As the average reproducing period of the adult female is six weeks, 

 and as the average number of young from each female is about 100, 

 there must be born from 9 to 1<) 3 oung every twenty-four hours. The 

 great labor of watching an individual female and removing every 

 twent3"-four hours the young she has given birth to during that period 

 has not been entered upon. Sufiicient observations have been made, 

 however, to indicate that the main period of reproductive activitv is 

 the second or third week after the female has reached maturity. At- 

 first the young are born with less frequency, and there is a correspond- 

 ing reduction in reproductive activity toward the end of the life of the 

 individual. The young are born indifferently ])y day or by night, per- 

 haps more during the day than during the night. In the morning. 



