NEW JERSEY 

 AGRICULTURAL EXPERIMENT STATIONS 



CIRCULAR 107 



VEGETABLE PLANT LICE* 



Introduction 



Information on the plant lice affecting vegetable crops is not 

 only limited but is scattered through various publications devoted to 

 other subjects. The experience of the past several years and espec- 

 ially last year has shown the great need for a publication which shall 

 bring our available knowledge together in a compact form, adapt it 

 to New Jersey conditions, and render it available to our vegetable 

 growers. 



With very few exceptions, among our growers there exists at 

 present no clear appreciation of the fact that different species with 

 different habits are concerned, no clear idea as to just what insecti- 

 cides should be used and just what strengths of the same are neces- 

 sary, no clear idea as to just what machinery is available, and no 

 clear idea as to just how the applications should be made. 



While information on all these points is altogether too limited, 

 there is a considerable amount of knowledge, which properly ar- 

 ranged and digested, should give the grower a great deal of help in 

 dealing with the problems of vegetable plant louse control. With 

 this idea in mind the following circular has been prepared and it is 

 hoped that it may in a measure, at least, meet the needs of our 

 growers. 



The Species of Plant Lice Concerned 



Ninety-four species of plant lice are recognized as af- 

 fecting various plants within the limits of the State of New Jersey. 

 Of this number 12 are known as enemies of vegetable crops and 

 of the vegetable infesting forms 6 or 7 are known to be seriously and 

 at times severely injurious. 



*Prepared February 26, 1919, by Thos. J. Headlee, Ph. D., Entomologist, 

 New Jersey Agricultural Experiment Station. 



(3) 



