﻿PREDACEOUS 
  ENEMIES. 
  19 
  

  

  the 
  clusters 
  were 
  blown 
  from 
  6 
  to 
  8 
  inches 
  from 
  where 
  they 
  would 
  

   naturally 
  drop, 
  but 
  it 
  is 
  very 
  unlikely 
  that 
  they 
  are 
  carried 
  any 
  

   distance 
  by 
  any 
  but 
  a 
  very 
  strong 
  wind. 
  

  

  The 
  only 
  probable 
  means 
  of 
  distribution 
  other 
  than 
  the 
  natural 
  

   migrations 
  are 
  by 
  horses 
  used 
  in 
  cultivating, 
  or 
  by 
  the 
  hands 
  and 
  

   clothing 
  of 
  the 
  men, 
  and 
  possibly 
  on 
  the 
  bodies 
  of 
  the 
  larger 
  insects 
  

   found 
  on 
  the 
  hopvines. 
  

  

  PREDACEOUS 
  ENEMIES. 
  

  

  Several 
  predaceous 
  insects 
  were 
  observed 
  destroying 
  red 
  spiders 
  on 
  

   the 
  hopvines 
  near 
  Sacramento, 
  CaL, 
  but 
  their 
  numbers 
  were 
  insuffi- 
  

   cient 
  to 
  have 
  any 
  effect 
  upon 
  the 
  infestation. 
  The 
  most 
  numerous 
  

   predaceous 
  insect 
  was 
  a 
  small 
  anthocorid 
  bug 
  (Triphleps 
  tristicolor 
  

   White) 
  . 
  This 
  insect, 
  both 
  in 
  the 
  nymphal 
  and 
  adult 
  stages, 
  was 
  very 
  

   common 
  in 
  some 
  sections 
  of 
  the 
  yards 
  and 
  was 
  frequently 
  seen 
  feeding 
  

   on 
  the 
  mites. 
  

  

  Certain 
  small 
  ladybirds 
  have 
  been 
  noticed 
  preying 
  upon 
  this 
  species 
  

   in 
  infested 
  yards, 
  but 
  were 
  not 
  found 
  in 
  large 
  numbers. 
  Among 
  these 
  

   are 
  the 
  following 
  : 
  

  

  Scymnus 
  nanus 
  Lee, 
  observed 
  at 
  Sacramento, 
  Cal., 
  July, 
  1911. 
  

  

  Scymnus 
  marginicollis 
  Mann., 
  observed 
  at 
  the 
  same 
  time 
  and 
  place. 
  

  

  Pentilia 
  sp., 
  found 
  in 
  some 
  infested 
  yards 
  but 
  present 
  only 
  in 
  small 
  numbers. 
  

  

  During 
  July 
  Chrysopa 
  calif 
  ornica 
  Coq., 
  in 
  the 
  larval 
  stage, 
  was 
  very 
  

   abundant 
  and 
  probably 
  did 
  more 
  good 
  than 
  all 
  the 
  rest 
  of 
  the 
  pre- 
  

   daceous 
  insects 
  together. 
  

  

  Dr. 
  F. 
  H. 
  Chittenden 
  1 
  reports 
  (Scymnus) 
  Stethorus 
  punctum 
  Lee, 
  

   Cecidomyia 
  coccidarum 
  Ckll., 
  Aphanogmus 
  varipes 
  Ashm., 
  Chrysopa 
  

   rufilabris 
  Burm., 
  and 
  (Tliri])s) 
  Scolotlirips 
  sexmaculatus 
  Perg. 
  as 
  feed- 
  

   ing 
  upon 
  the 
  red 
  spider 
  at 
  Washington, 
  D. 
  C, 
  and 
  elsewhere. 
  

  

  Mr. 
  E. 
  A. 
  McGregor, 
  2 
  an 
  agent 
  of 
  this 
  bureau, 
  has 
  recorded 
  the 
  fol- 
  

   lowing 
  natural 
  enemies 
  of 
  the 
  red 
  spider 
  on 
  cotton 
  at 
  Batesburg, 
  

   S. 
  (\, 
  in 
  1912: 
  

  

  Triphleps 
  insidiosus 
  Say. 
  

  

  Chrysopid 
  larvae. 
  

  

  Euthrips 
  fuscus 
  1 
  1 
  inds. 
  

  

  Euthrips 
  occidentalis 
  Perg. 
  

  

  Scolothrips 
  sexmaculatus 
  Perg., 
  recorded 
  by 
  both 
  Pergande 
  and 
  Duffy. 
  

  

  Coccinella 
  9-notata 
  Hbst. 
  (larvae). 
  

  

  Hippodamia 
  convergent 
  Guer. 
  (larvae). 
  

  

  While 
  predaceous 
  insects 
  destroy 
  many 
  of 
  the 
  mites 
  in 
  the 
  hop 
  

   fields, 
  their 
  work 
  has 
  do 
  appreciable 
  effeel 
  upon 
  the 
  infestation. 
  

  

  1 
  The 
  common 
  red 
  spider, 
  Ctr. 
  104, 
  Bur. 
  Km., 
  r. 
  8. 
  Depl 
  

  

  * 
  The 
  rod 
  spider 
  on 
  cotton, 
  Cir. 
  150, 
  Bur. 
  Km., 
  U.S. 
  Dept. 
  \ 
  \ 
  . 
  L913, 
  

  

  