168 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



many plots similar to what are shown on these charts, using such 

 food plants as hemp, peony, dahlia, corn, potatoes, tomatoes, golden 

 glow, asters, tiger lilies, hollyhocks, giant bur-elder, giant ragweed, 

 burdock, daisies, sunflowers, etc., we may say briefly that the most 

 effective barrier found was a thin board smeared with tanglefoot on 

 the outside. This board was about one eighth of an inch thick, and 

 about five inches wide, and placed in the ground edgewise, around 

 the four sides of the plot. The tanglefoot should be put on an inch 

 or so above the ground, so that it could not be easily coated with 

 earth by the spattering occasioned in the event of heavy showers; 

 and whatever sticky substance is used, it should be of such a nature 

 as to either remain sticky, or be kept sticky by several applications, 

 from June 1st to August 1st. 



The fact that the larvas show a strong tendency, when within about 

 two feet of their favorite food plants, to go to said food plants 

 directly, suggests that possibly a barrier of weeds might be placed 

 around a garden, thus providing the caterpillars hatched outside the 

 garden with food, and making it unnecessary for them to travel to 

 the flower beds. These would have to be burned in the fall, of course. 

 They would have to be in position during the last of May, or early 

 part of June. 



Parasites : These two species appear to be extensively parasitized, 

 since we have reared many individuals of Tachinids from them. 

 From P. cataphracta, Hypostena variabilis Coq., and from P. nitela 

 also an Exorisfa sp. also Masicera myoidcea Desv. in large numbers, 

 the last named being identified by Professor Aldrich. From a breeding 

 cage containing both species we reared what I regard as Ichneumon 

 Icetus, and evidently Ichneumon orpheus Cress. From some material 

 emerging from the pupa of P. nitela Professor Aldrich also named 

 for us an Ortalid, CJuetopsis aencea Wied. 



We have considerably more parasitic material from these two 

 species of at least one genus and parasitic. 



Mr. Sanderson : I would like to inquire if the leaf hopper causes 

 serious damage to old apple trees? Does the work of this insect 

 affect the growth of old trees seriously ? 



Mr. Brues: In regard to the Ortalids, it is well known that the 

 species of at least one genus are parasitic. 



Mr. Sanderson: The reason I asked these questions was because 

 some trees in New Hampshire have suffered in the past season from 

 the attack of leaf hoppers. 



