12 



BULLETIN 1373, U. S. DEPARTMENT OP AGRICULTURE 



Table 3. — Period of pupation of the bud moth, Wallingford, Conn., 1920 and 

 1921 — Summary of Table 2 



Number of days 



Number of 

 individuals 



1920 



1921 



12 days— 



13 days 



14 days 



15 days 



16 days 



17 days.. 



18 days 



19 days 



20 days 



21 days.... 



Total 



Average number of days 



53 



15.3 



The emergence of the moths covers a period of a month or more, 

 following from two to three weeks after pupation. In 1920, the 

 moths were emerging in the insectary from June 24 to July 24; in 

 1921, a single moth was noted in the field on June 8, and moths 

 emerged in the insectary from June 15 to July 16. 



The moths are active chiefly at night, and are not often noted in 

 the daytime. Mating was not observed in the insectary at Walling- 

 ford, but apparently occurred at night, and fertile eggs were laid in 

 fair numbers in the jars used for oviposition. Egg-laying com- 

 menced in from 2 to 5 days after emergence, usually on the second 

 or third day, and continued from 1 to 11 days, although the greater 

 part of the eggs were usually laid during the first Q or 3 days of 

 oviposition. Confined in battery jars, some of the moths refused to 

 lay at all ; others deposited a few eggs, while others laid very freely. 

 The greatest number of eggs laid by any one moth was 156. Eggs 

 were deposited on both sides of apple or pear foliage, usually singly, 

 but occasionally several overlapping one another. In captivity one 

 female moth lived 15 days and a male 16 days, the average length of 

 life in 1920 being 7.5 days for the females and 7 days for the males. 

 In 1921 the average was 11.6 days for the females and 12.2 days for 

 the males. 



Four or five days after the eggs are laid, the exact length of time 

 depending upon weather conditions, certain changes become evi- 

 dent. At this time two dark dotsi become visible through the thin 

 shell of the egg, indicating the presence of the two groups of ocelli. 

 In six or seven days the brown mandibles and other mouth parts ap- 

 pear; shortly afterwards the dark head and thoracic shield become 

 evident, and the outline of the larva becomes very faintly visible. At 

 the end of the seventh day occasional larvae hatch if the weather has 

 been especially warm, but the greater part of them hatch in 8 to 10 

 days, the incubation period, according to Table 4, being approxi- 

 mately 9 days under ordinary midsummer conditions in Connecticut. 



