December, '17] HAWLEY: HOP REDBUG 545 



THE HOP REDBUG (PARACALOCORIS HAWLEYI KNIGHT)^ 



By I. Myron Hawley 



During the past few years hop plants in the yards about Waterville, 

 N. Y., and especially in the vicinity of Sangerfield, have shown con- 

 spicuous injury to the fohage by perforations of the leaves and also by a 

 stunting and deformation of the stems. In June, 1913, there were 

 several yards at Sangerfield notably injured in this manner. Careful 

 examination of the affected plants disclosed the presence of large num- 

 bers of red nymphs with white markings. When these 3'ards were 

 examined the first part of July, the nymphs were feeding on the vines 

 and sap was flowing from the wounds which they had made. A few 

 adults were taken at this time, which later were found to belong to the 

 family Miridse. Because of their striking color the writer has called 

 them the hop redbug. Each year since 1913 the insect has increased 

 greatly in numbers and caused more and more injury. It may now 

 be found in yards ten miles from Sangerfield but does not appear to 

 have reached the Cooperstown district, thirty miles distant. 



The writer submitted a large series of specimens for examination to 

 H. H. Knight, who reported them as representing a new species and 

 described it as Paracalocoris hauieyi. Later the determination was 

 confirmed by W. L. McAtee, who in addition described several varie- 

 ties of the species. The drawings of the various stages are by Miss 

 A. C. Stryke. 



Nature of the Injury 



The injury may be recognized by the deformed and stunted vines 

 (PL 28, Fig. 1) and the irregular holes in the leaves (PI. 28, Fig. 2). The 

 initial injury is made evident by many hght spots in the still unfolded 

 leaves. On close examination it is found that the epidermis is broken 

 on the under side. Later, as growth continues, a dead area is produced 

 and, when this drops out, irregular holes result. The early work is found 

 about the middle of June, and by the middle of July the leaves may be 

 completely riddled. 



In the later stages a nymph may feed on the vines, causing the sap 

 to fiOW from the punctures. As the vine grows it will often become 

 stunted on the side attacked, and by continuing its growth on the 

 opposite side, a sharp bend will be formed. A plant is often weakened 

 so that its clinging power is lost. The main stems will tend to hang 

 down and often all the vines of the hill will slip down around the base of 

 the pole (PI. 28, Fig. 3). The older nymphs may also feed on the burrs 



1 Contribution from Entomological Laboratory of Cornell University. 

 3 



