1919] ECONOMIC ZOOLOGY ENTOMOLOGY. 161 



imnianis) and methods of control. Two new pests, tlie hop redbug {Paracalo- 

 coris liatvlcyi) and the filamented looper (Nematocampa limbata) were also 

 studied, as was the hop snout moth {Hypena humuli), an old but little-known 

 pest. In addition some conti'ol experiments were conducted with the hop 

 aphis under New York conditions, and notes are presented on several pests of 

 lesser importance, namely, the red spider or spider mite {Tetranychm telarius), 

 the hop merchants (Poly(/onia interrogationis and P. comma), leaf hoppers 

 (Empoasca, flavescens and E. flavescens birdii), a milliped (Julus cwruleo- 

 cinctus), a leaf miner {Agrcynvyza sp. ), flea beetles {Psylliodes punctulata 

 etc.), and leaf rollers (Archips rosaceana and A, argyrospila) . A list of sev- 

 eral others is included. 



The hop vine borer is a native insect, widely distributed in the northern 

 United States and in Canada, which is only known to reach maturity on the 

 hop. The injury is done to the head of the hop, the inside and outside of the 

 vines, and in the roots. The loss occasioned varies greatly in different years 

 and in different yards in any one year. In one yard in which the author 

 worked, there were 90 dead vines in 100 hills, or a total loss of 20 per cent from 

 the work of this insect, which is said to be a conservative estimate for the 

 yard. 



The eggs are laid on grass in and around hop yards from the middle of 

 August to the last of September. The winter is passed in this stage and they 

 hatch from the last week in April to the last of May. In an examination of 

 distended females dissected, 866, 72.5, 457, and 612 eggs were obtained. Upon 

 hatching out the larvae make their way into grass or hop plants. " In grass 

 they eat into the stem near the surface of the ground and feed upward, killing 

 the central blade. They leave the grass at about the time other larvse leave 

 the inside of the hop. In the hop the young grubs enter the part that is the 

 most readily available and easy to penetrate, which may be the head or any 

 part of the vine. If the larva enters the head, it drops to the ground in about 

 two weeks and helps to increase the large number already working in the vine 

 near the root. About the first of June, when the larva is in the third or the 

 fourth stage, it stops inside work and either feeds on the outside of the vine, 

 nearly or quite severing it, or makes burrows in the root. In .Tuly or the first 

 part of AugiTst the larva pupates, and the moth emerges the last of August 

 or early in September." There appears to be six larval stages, the entire length 

 of which is from 9 to 12 weeks. The length of the pupal stage in the laboratory 

 varied from 35 to 37 days. 



MicropliUs gortyncc, a braconid, is a common parasite of the larva and two 

 tachinids {Frontirm frenchii and Masicera myoidea) apparently attack it. 

 Control work, the details of which are reported in tabular form, has led to the 

 recommendation (1) that all extra vines be pulled and removed some distance 

 from the yard before June 1, (2) that the hops be hilled so as to give the extra 

 rootlets an opportunity to grow, (3) that clean cultivation be practiced by 

 removal of grass from the yard, and (4) that a plowed border several yards 

 wide be maintained around the field. The use of paradichlorbenzene, a few 

 crystals in each hill and covered with about 2 in. of dirt, about the third week 

 in May may prove to be worth while. 



The hop redbug has caused conspicuous injury to the foliage by perforations 

 of the leaves and also a stunting and deformation of the stems during the past 

 few years in yards about Waterville. The injury which it causes may be recog- 

 nized by the deformed and stunted vines and the irregular holes in the leaves. 

 The eggs which are inserted in the bark or the wood of hop poles from the 

 middle of August to the middle of September hatch during the following June, 

 or an egg period of 9 to 9.5 montlis, There are five nymphal stages for the 



