1924 





ENTOMOLOGICAL SOCIETY 



25 



Table 2 — Nicotine Sulphate 1-1600, and no Lime. 



3 



2 



378 

 354 



1-2 days 

 9-10 " 



15.1 

 22.6 



49.7 

 46.6 



64.8 

 69.2 



5 



732 











Table j — Nicotine Sulphate 1-1200, Hydrated Lime 5 Pounds — 40 Gallons. 



6 



5 

 2 



568 

 513 

 538 



1-2 days 

 9-10 " 

 18-19 " 



47.2 

 57.3 

 6/. 6 



52.8 

 42.7 

 32.4 



100 

 100 

 100 



13 



1,619 











Table 4 — Nicotine Sulphate 1-800, Hydrated Lime 5 Pounds — 40 Gallons. 



2 

 3 

 2 



477 

 519 

 491 



1-2 days 

 9-10 " 

 18-19 " 



63.5 

 71.8 

 78.4 



36.5 

 28.2 

 21.6 



100 

 100 

 100 



1 

 t 



1,487 











Table 5 — ^Nicotine Dust — 2.2 Per Cent. Nicotine. 



No. of tests 



No. of eggs 



Age of eggs when 

 treated 



% killed in 

 egg stage 



% nymphs which 

 died while hatching* 



% total 

 mortality 



3 

 3 

 4 



482 

 508 



528 



1-2 days 

 8-9 " 

 18-19 " 



8.8 

 20.2 

 26.9 



20.1 

 33.0 

 46.7 



28.9 

 53.2 

 73.6 



10 



1,518 











Table 6 — Checks. 



8 



602 





5.7 



6.3 



12.0 



Effect of Nicotine on Eggs of E. Comes 

 Table 7 — Nicotine Sulphate 1-1600, Hydrated Lime 5 Pounds — 40 Gallons. 



No. of 

 experiments 



No. of eggs 



Age of eggs when 

 treated 



% killed in 

 egg Stage 



% nymphs which 

 died while hatching * 



% total 

 mortality 



5 

 6 



5 



516 

 480 

 477 



9-10 days 



Newly laid 



About to hatch 



85.7 

 65.0 

 67.1 



14.3 

 26.0 

 32.9 



100 

 91.0 

 100 



16 



1,473 











Table 8 — Checks. 



2 



104 





11.5 



i 



11.5 



These laboratory experiments demonstrated that newly-laid eggs are some- 

 what less susceptible to nicotine than those over eight days old; that nicotine 

 dust is unsatisfactory as an ovicide; that the addition of lime apparently 

 increases the ovicidal value of the nicotine sulphatej; that nicotine sulphate 



* Nymphs succumbed in process of hatching. None of them actually emerged from the eggs. 

 t Niagara D-ll. 



} See tables 1 and 2. A shortage of plants made it impossible to carry on a larger series of 

 . tests of nicotine sulphate without lime. 



