254 BUSH-FRUITS 



drain the sap of these succulent growing parts. The effect is to 

 arrest the development of the leaves, or even to kill them, and 

 in the case of the strawberry, to interfere with the growth of 

 the fruit; sometimes, at least, causing what is known as the 

 "buttoning" of the berry. Later in the season, the buds and 

 leaves of flowering plants and vegetables, especially the cabbage 

 and potato, are attacked. 



"There are at least two broods in a year, one maturing in 

 May and June, the other in July and August, while it is possible 

 that there is still another intermediate. 



"Although a few of these insects are devoured by birds, no 

 natural enemies are known to have any positive effect upon 

 their numbers. There is some evidence, however, that wet 

 seasons are injurious to them." 



Remedies. Obtaining their food by sucking .the juices as 

 they do, the arsenites are of no value in preventing their depre- 

 dations. Pyrethrum has proved most satisfactory where the 

 expense is not too great. Kerosene emulsion also kills them, 

 and collecting them with insect nets during the cooler parts of 

 the day has sometimes proved practicable. 



THE BRAMBLE FLEA- LOUSE 

 Trioza tripunctata, Fitch. Order Hemiptera: Family PsyllidaB 



Psylla tripunctata (Fitch). 



Fuller, Amer. Ent. 3:62. 



Thomas, 111. Ent. Rep. 8:18. 

 Psylla rubi, Walsh and Riley, Amer. Ent. 1:225. 



Thomas, 111. Ent. Rep. 8:17. 



Strong, Fruit Cult. 179. 



This insect belongs to a family closely related to the Aphides, 

 differing in the veining of the wings, and in having antenna 

 knobbed at the end. They jump as readily as a flea. The fol- 

 lowing account of their injury was given by Charles Parry, of 

 Cinnaminson, New Jersey, in 1869: 



"The suckers upon which this insect occurs in the spring 

 commence to twirl around, and, when not interfered with, make 



