June, '17] LOVETT: NICOTINE AN INSECT POISON 333 



FRUIT-FLIES OF ECONOMIC IMPORTANCE IN 

 CALIFORNIA 



By Henry H. P. Severin, Berkeley, Cal. 



(Withdrawn for publication elsewhere) 



The paper was discussed by H. E. Burke, A. W. Morrill, R. W. 

 Doane and others. 



Chairman A. W. Morrill: The next paper, by Prof. A. L. Lovett, 

 will be read by the secretary. 



NICOTINE SULPHATE AS A POISON FOR INSECTS 



A. L. Lovett, Entomologist, Oregon Agricultural Experiment Station 



A suggestion of nicotine sulphate as a stomach poison for insects 

 was first brought to the writer's attention after reading the report of 

 Mr. F. E. DeSellem, inspector at large, of North Yakima, Washington, 

 on Black Leaf 40 as a spray for the codling moth. 



Since the completion of the work included in this paper, has ap- 

 peared the excellent article on "Nicotine as an Insecticide" by Mr. 

 Mclndoo, in the Journal of Agricultural Research, and still more re- 

 cently the 1916 Horticultural Report of Yakima County, Washington, 

 with the two seasons' rather startling results of ]\Ir. DeSellem on the 

 control of the codling moth. The results included in this paper supple- 

 ment both in a measure and are offered as additional data on a very 

 interesting topic. Nicotine sulphate as a contact insecticide is con- 

 sidered a very efficient, but expensive spray. The possibility of its 

 broader insecticidal properties in commercial spraying as indicated in 

 these papers may alter our present conception as to value versus 

 service. 



Series 1. For Foliage Eating Caterpillars 



The caterpillars used in the tests were our common tent caterpillars 

 (Malacosoma pluvialis Stretch). They were collected, tent and all, in 

 the field feeding on the foliage of the wild rose. With the exception 

 of Experiment A the foliage was allowed to dry for hours after applying 

 the spray before introducing the caterpillars. 



Experiment A. 



April 9, 1916. 9.00 a. m. 

 Sprayed foliage of wild rose with "Pratt's Nicotine 40" 1-400, 

 thoroughly saturating the foliage with a fine misty spray. Placed 

 approximately 600 newly hatched larvse of the tent caterpillar (M. 



