86 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table IV. — Tests of the killing effect on the fall webworm of lime-sulphur and arsenate 

 of lead, alone and combined. 



[Experiment started Aug. 19, 1912, Benton Harbor, Mich., 201arvee in each lot.] 





Larvse dying in each lot. 



Date of examina- 

 tion. 



Lotl— 



Check 



(un- 



sprayed). 



Lot 2— 

 Lime- 

 sul- 

 phur, 

 i-50. 



Lot 3— 

 Lime- 

 sul- 

 phur, 

 |-50. 



1 

 Lot 4 — Lot 5— 

 Lime- Lime- 

 sul- i sul- 

 phur, i phur, 

 1^-50. j 3-50. 



Lot 6— 

 Arse- 

 nate of 

 lead, 

 i-50. 



Lot 7— 



Arse- 

 nate of 

 lead, 

 1-50. 



Lot 8— 

 Arse- 

 nate of 

 lead, 

 2-50. 



Lot 9— 



Arse- 

 nate of 

 I ead, 

 3-50. 



Lot 10— 

 Arse- 

 nate of 

 lead, 

 5-50. 



Aug. 21... 







1 



2 



1 

 7 

 7 

 2 



! 3 



2 2 



8 1 9 

 10 6 



2 

 8 

 7 

 3 



3 



10 

 7 



4 

 2 

 14 



5 

 13 

 2 





23 





1 



2 

 8 

 8 

 1 



g 



25 







27 j 





29 











31 













Sept. 2 ! 















4 j 



















6 







! 









8 









1 1 









10 





















15 



3 

 5 







i 













Oct. 3 







| 































Total num- 

 ber dead. .. 

 Number days re- 



8 



20 



12 



3.51 



20 

 12 



2.87 



20 



8 



0.17 



20 



8 



0.49 



20 



10 



2.44 



20 



6 



0.36 



20 



6 



0.57 



20 



6 



0.24 



20 

 4 



Square inches of 

 foliage consumed. 



72.00 



0.02 





Larvge dying in each lot. 



Date of examination. 



Lot 11— 



Lime- 

 sulphur, 



l|-50; 



arsenate 



of lead, 



£-50. 



Lot 12— 



Lime- 

 sulphur, 



l|-50; 



arsenate 



of lead, 



1-50. 



Lot 13— 



Lime- 

 sulphur, 



li-50; 



arsenate 



of lead, 



2-50. 



Lot 14— 



Lime- 

 sulphur, 



li-50; 



arsenate 



of lead, 



5-50. 



Lot 15— 

 Arsenate 

 of lead, 



2-50; 



lime- 

 sulphur, 



i-50. 



Lot 16— 

 Arsenate 

 of lead, 



2-50; 



lime- 

 sulphur, 



|-50. 



Lot 17— 

 Arsenate 

 of lead, 



2-50; 



lime- 

 sulphur, 



U-50. 



Lot 18— 

 Arsenate 

 of lead, 



2-50; 



lime- 

 sulphur, 



3-50. 



Aug. 21 







3 

 9 



7 

 1 



10 

 10 



9 

 9 

 2 



5 



11 

 4 



1 

 6 

 13 



6 



23 



2 



14 

 4 

 2 



9 



25.. 



8 





27... 6 







29 4 













31 [ 

















Sept. 2... 

















4 , 















6 ! 











1 





8 . . i 

















io... ..! 

















15 1 

















Oct. 3. . 













Total number 



dead 



Number days re- 

 quired to kill 



Square inches of foli- 

 age consumed 















20 



10 



0.52 



20 



8 



0.02 



20 



8 



0.28 



20 



4 



0.07 



20 



6 



0.30 



20 



6 



0.19 



20 



6 



0.06 



20 

 6 



0.22 



None of the larvae on the unsprayed lot died until September 15, 

 27 days after the experiment was started. On October 3 the records 

 of this lot showed 8 dead, 6 pupated, and 6 missing. Lime-sulphur 

 alone, |-50, and likewise f-50, killed all the larvae in 12 days, while 

 the time required by strengths of 1 J-50 and 3-50 was 8 days in each 

 case, the rapidity of killing being somewhat greater with the latter 

 strength. Arsenate of lead alone, J-50, killed the 20 larvae in 10 days, 

 or 2 days more than was required by lime-sulphur, 1^-50. Arsenate 



