﻿CONTENTS. 
  

  

  Page. 
  

  

  Introduction 
  1 
  

  

  Treatment 
  of 
  nymphs 
  of 
  the 
  grape 
  leafhopper 
  with 
  contact 
  sprays 
  1 
  

  

  Field 
  experiments 
  with 
  tobacco 
  extracts 
  2 
  

  

  Vineyard 
  experiments 
  in 
  1911 
  3 
  

  

  Experiment 
  in 
  vineyard 
  of 
  Mr. 
  H. 
  H. 
  Harper, 
  North 
  East, 
  Pa 
  3 
  

  

  Experiment 
  in 
  vineyard 
  of 
  Mr. 
  W. 
  E. 
  Gray, 
  North 
  East, 
  Pa 
  5 
  

  

  Experiment 
  in 
  vineyard 
  of 
  Mr. 
  J. 
  E. 
  Beatty, 
  North 
  East, 
  Pa 
  7 
  

  

  Experiment 
  in 
  vineyard 
  of 
  Mr. 
  D. 
  0. 
  Bostwick, 
  North 
  East, 
  Pa 
  7 
  

  

  Use 
  of 
  combined 
  contact 
  and 
  poison 
  spray 
  9 
  

  

  Effect 
  of 
  grape 
  leafhopper 
  control 
  on 
  quality 
  of 
  fruit 
  10 
  

  

  Conclusion 
  12 
  

  

  ILLUSTRATIONS. 
  

  

  Page. 
  

   Plate 
  I. 
  Spraying 
  against 
  the 
  grape 
  leafhopper. 
  Fig. 
  1. 
  — 
  Rod 
  and 
  single 
  

   cyclone 
  nozzle 
  used 
  to 
  apply 
  spray 
  to 
  underside 
  of 
  grape 
  foliage. 
  

   Power 
  supplied 
  by 
  tractor 
  sprayer. 
  Vineyard 
  of 
  Mr. 
  H. 
  H. 
  

   Harper, 
  North 
  East, 
  Pa. 
  Fig. 
  2. 
  — 
  Rod 
  carrying 
  two 
  cyclone 
  nozzles 
  

   used 
  to 
  apply 
  spray 
  to 
  underside 
  of 
  grape 
  foliage. 
  Power 
  supplied 
  

   by 
  compressed 
  air. 
  Vineyard 
  of 
  Mr. 
  A. 
  I. 
  Loop, 
  North 
  East, 
  Pa. 
  4 
  

  

  II. 
  Comparison 
  of 
  sprayed 
  and 
  unsprayed 
  plats. 
  Fig. 
  1. 
  — 
  Showing 
  con- 
  

   dition 
  of 
  vine 
  injured 
  by 
  grape 
  leafhopper 
  in 
  unsprayed 
  plat. 
  

   Note 
  loss 
  of 
  foliage 
  and 
  also 
  berries 
  from 
  clusters. 
  Vineyard 
  of 
  

   Mr. 
  W. 
  E. 
  Gray, 
  North 
  East, 
  Pa. 
  Fig. 
  2.— 
  Showing 
  condition 
  

   of 
  vine 
  in 
  plat 
  sprayed 
  with 
  tobacco 
  extract 
  No. 
  I 
  against 
  grape 
  

   leafhopper. 
  Note 
  larger 
  size 
  of 
  berries 
  in 
  clusters, 
  heavy 
  foliage, 
  

   and 
  stronger 
  cane 
  growth. 
  Vineyard 
  of 
  Mr. 
  W. 
  E. 
  Gray, 
  North 
  

  

  East, 
  Pa 
  8 
  

  

  III. 
  Spraying 
  against 
  the 
  grape 
  leafhopper. 
  Fig. 
  1. 
  — 
  Gasoline-engine 
  

   sprayer 
  supplying 
  power 
  for 
  two 
  ''trailer" 
  leads 
  of 
  hose 
  in 
  spray- 
  

   ingagainst 
  grape 
  leafhopper. 
  Vineyard 
  of 
  Mr. 
  J. 
  E. 
  Beatty, 
  North 
  

   East, 
  Pa. 
  Fig. 
  2. 
  — 
  Gasoline-engine 
  sprayer 
  supplying 
  power 
  for 
  

   two 
  "trailer" 
  Leads 
  of 
  hose 
  in 
  spraying 
  against 
  grape 
  Leafhopper. 
  

   Vineyard 
  of 
  Peacock- 
  Hood 
  Co., 
  West 
  field. 
  XV 
  8 
  

  

  text 
  FIGURES. 
  

  

  Page. 
  

  

  Fio. 
  I. 
  — 
  The 
  grape 
  leafhopper 
  ( 
  Typhlocyba 
  comes 
  var. 
  coloradensis 
  : 
  Adult 
  1 
  

  

  2. 
  — 
  The 
  grape 
  leafhopper: 
  Nymph 
  of 
  the 
  firel 
  Btage 
  2 
  

  

  3.— 
  The 
  grape 
  Leafhopper: 
  Fully 
  developed 
  nymph 
  of 
  the 
  fifth 
  stage 
  \i 
  

  

  in 
  

  

  