28 



BULLETIN 265, U. S. DEPARTMENT OF AGRICULTURE. 



One mated female deposited a total of 133 eggs, and another escaped 

 after depositing 95 eggs. Two single females were observed one 

 of which deposited 83 eggs and the other 104. 



FOURTH GENERATION. 



Incubation period of fourth-brood eggs. — The length of the fourth- 

 brood egg stage averages a little shorter than that of the second 

 brood, the weather in August being warmer than in June. Records 

 of 174 fertile eggs showed an average incubation period of 3.8 days, 

 and records of 62 parthenogenetic eggs deposited during the same 

 period showed an average of 4.4 days. Table XVIII gives the 

 records for the 174 fertile eggs, and for 157 parthenogenetic eggs, 

 95 of them being deposited from August 31 to September 4, when the 

 weather was cooler. „ This makes the total average higher than that 

 of the fertile eggs, as no records of these were secured during this 

 cooler period. 



Table XVIII. 



-Length of the incubation period of fourth-brood eggs of the dock false- 

 worm, Wenatchee, Wash., 1915. 



Fertile eggs. 



Parthenogenetic eggs. 



Number 

 of eggs. 



Date- 



Incu- 

 bation 

 period. 



Total 



days. 



Number 

 of eggs. 



Date— 



Incu- 

 bation 

 period. 



Total 



days. 



posited. Hatched " 



poStV Hatched - 



1 



26 



19 



41 



28 



6 



1 



25 



1 



1 



11 



11 



3 



Aug. 18 

 ...do 

 ...do 



Aug. 19 

 ...do 

 ...do 

 ...do 



Aug. 20 



...do 



...do 



Aug. 21 

 ...do 

 ...do 



Aug. 21 

 Aug. 22 

 Aug. 23 

 Aug. 22 

 Aug. 23 

 Aug. 24 

 Aug. 25 

 Aug. 24 

 Aug. 25 

 Aug. 26 

 Aug. 24 

 Aug. 25 

 Aug. 26 



3 

 4 

 5 

 3 

 4 

 5 

 6 

 4 

 5 

 6 

 3 

 4 

 5 



3 



104 



95 



123 



112 



30 



6 



100 



5 



6 



33 



44 



15 



14 

 12 

 10 

 11 

 8 

 6 

 1 

 1 



18 

 2 

 2 

 10 

 19 

 1 



14 

 1 

 20 

 3 

 4 



Aug. 20 

 ...do 



Aug. 21 

 ...do 



Aug. 22 

 ...do 



Aug. 23 



Aug. 31 

 ...do 



...do 



...do 



Sept. 1 

 ...do.... 

 ...do 



Sept. 2 



Sept. 3 

 ...do 

 ...do 



Sept. 4 



Aug. 24 

 Aug. 25 



...do 

 Aug. 26 



...do 

 Aug. 27 



...do 

 Sept. 6 

 Sept. 7 

 Sept. 8 

 Sept. 9 

 Sept. 7 

 Sept. 8 

 Sept. 9 

 Sept. 8 



...do 



Sept. 9 

 Sept. 10 

 Sept. 11 



4 

 5 

 4 

 5 

 4 

 5 

 4 

 6 

 7 

 8 

 9 

 6 

 7 

 8 

 6 

 5 

 6 

 7 

 7 



56 

 60 

 40 

 55 

 32 

 30 



4 



6 



126 



16 



18 



60 



133 



8 

 84 



5 

 120 

 21 

 28 



174 



676 



157 



902 





incubatioi 





__ 3.8 







.. 5.7 



Maximu 

 Minimu 





6 - 



3 



Maximur 

 Minimun 



Q 



1 







9 

 4 



Length of life of fourth-brood larvx by instars. — As the fourth-brood 

 larvse do not pupate the same season, but pass the winter in the 

 larval stage, only the period from hatching to the forming of the pupal 

 or hibernating cell by these larvse is given in the summary in 

 Table XIX. 



