16 



BULLETIN 901, U. S. DEPARTMENT OF AGRICULTURE. 



Table XVII. — Time and duration of immature stages in the ground of Altica woodsi, 



North East, Pa., 1916. 



Date of 

 entering 

 ground. 



Date of 

 emergence. 



Number 

 of indi- 

 viduals. 



Duration 

 of period. 



Date of 

 entering 

 ground. 



Date of 

 emergence. 



Number 

 of indi- 

 viduals. 



Duration 

 of period. 



July 7 

 10 

 10 

 10 

 15 

 16 

 17 

 17 

 18 

 18 

 19 

 21 

 21 



July 24 



24 



25 



26 



29 



Aug. 5 



July 31 



Aug. 2 



2 



6 



2 



5 



6 



1 



7 

 2 

 1 

 3 

 3 

 2 

 1 

 1 

 7 

 1 

 3 

 7 



Days. 

 17 

 14 

 15 

 16 

 14 

 20 

 14 

 16 

 15 

 19 

 14 

 15 

 16 



July 21 

 24 



Aug. 1 

 1 

 3 

 " 6 

 6 

 8 

 8 

 8 



Aug. 7 

 7 

 16 

 17 

 19 

 21 

 25 

 25 

 26 

 29 



1 

 1 

 1 

 1 

 3 

 3 

 1 

 1 

 1 

 1 



Days. 

 17 

 14 

 15 

 16 

 16 

 15 

 19 

 17 

 18 

 21 



153 



2 16. 15 



i Total. 



2 Weighted average. 



EMERGENCE PROM HIBERNATION, 1917. 



A few beetles emerged from hibernation in the latter part of May, 

 but they were not abundant until the early part of June. The first 

 specimens were collected May 19 on wild grape, when Concord grape 

 shoots were about 8 inches long and the flower buds were showing. 



None were collected on 



-Incubation period of A. woodsi, North -,,. , i , .-, 



East, Pa 1917. cultivated grapes until 



June 3, when they were 

 common. They in- 

 creased in numbers 

 until about June 9. 



Table XVIII.- 



Date of 



Date of 



Number 



Duration 



oviposition. 



hatching. 



of eggs. 



of period. 









Days. 



July 19 



July 2 



16 



13 



19 



3 



8 



14 



20 



3 



6 



13 



20 



4 



17 



14 



21 



5 



2 



14 



21 



6 



2 



15 



22 



6 



12 



14 



23 



7 



8 



14 



171 



2 13. 72 



OVIPOSITION. 



July. 



Oviposition began 

 about 18 days after the 

 emergence of the earli- 

 est adults and continued 

 until the latter part of 

 The latest recorded date of oviposition was July 26. The 



i Total. 



2 Weighted average. 



longest recorded period of oviposition for a single female was 41 

 days, from June 12 to July 23; this beetle deposited eggs on 17 days 

 during that period. The number of eggs deposited by four isolated 

 females varied from 37 to 181, with an average of 102.5 eggs each. 

 Thirty-one eggs is the largest number deposited on a single day. 



INCUBATION. 



The duration of the incubation peri 3d of 71 eggs varied from 13 to 

 15 days, with an average of 13.72 days, as shown in Table XVTII 



