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 ^         S**^       U.  S.  DSPJlR'TimTT  CF  AGRICUITO:-:]!; 
 ^  Z*  BUEEAU  0?  ENTOMOLOGY 
 
 p  O-  ^"^   <j^.     Division  of  Insects  :\i"foctinr  Han  ?nd  Aninials, 
 
 E-306 
 
 "S.4ITD  ZLIES"  AlID  "FU^TFJES" 
 
 Biting  midges,  knovm  as  "sand  flies,"  "sand  gnats."  "no- see- -urns,"  "pinkies," 
 and  "by  other  names,  conrprise  atout  30  species  of  tiny  "blood- sucking  insects.   The 
 most  important  of  these  occur  where  fresh- water  strec'jns  pejrait  entrance  of  salty 
 tidal  water.  At  different  points  along  the  South  Atlantic  and  Gulf  coasts  the 
 annoyance  caused  hy  blood- sucking  midges  sorio^isly  affects  valiies  or  prevents  de- 
 velopment of  water-front  properties.  Many  inland  localities,  especially  in  the 
 mountains,  are  infested  with  different  species  of  midges  which  also  limit  outdoor 
 seasonal  activities  aiid  cause  much  disconfort  to  people.   These  insects  also  attack 
 livestock  and  game  animals.  All  of  these  midges  are  small  enough  to  pass  thro-'Jgh 
 the  ordinary  wire  screen  of  windows  and  mo5t  of  them  are  attracted  to  lights  in 
 residences.   They  are  easily  killed  rrith  the  coiimonly  sold  pyrcthrum  spray,  but 
 such  a  measure  is  recommended  only  as  a  means  of  terrocrary  relief  from  them.   It^  is 
 much  better  to  prevent  development  of  these  pests  ^o-j  measures  directed  against  thei: 
 breeding  places. 
 
 There  is  much  yet  to  be  learned  about  sand  flies  and  their  control,  as  it  is 
 only  recently  that  thR  Bx^.reau  of  Entomology  began  a  systematic  study  of  this  prob- 
 lem. The  work  is  still  under  way,  and  some  of  the  methods  of  control  suggested 
 have  not  been  tested  thoroughly.  Ho  doubt  others  will  bo  developed  in  the  course 
 of  the  work. 
 
 In  general,  the  breeding  places  of  blood- sucking  midges  are  of  two  types — 
 those  in  salt  marshes  and  those  in  rot  holes  of  trees,  A  hole  in  a  shade  tree  can 
 furnish  a  sufficient  nmber  of  midges  to  a^moy  the  members  of  an  entire  household. 
 It  is  a  good  idea  to  examine  the  shade  trees  about  the  house  very  carefully.  If 
 rotted  holes  are  found  they  can  be  trimmed  so  as  to  permit  them  to  drain.   The 
 trimmed  surface  shoiold  then  be  treated  with  creosote  so  as  to  prevent  further  rot- 
 ting and  permit  healing,  or  the  cavity  can  be  filled  with  coiJ.C2'3te.  Croosoted  pine 
 sap,  a  waste  product  from  plants  which  creosote  pine  lumber,  can  be  used  in  treat- 
 ing rot  holes.   It  is  inexpensive  and  is  highly  toxic  to  midge  maggots  and  mosquito 
 larvae.   Tree  holes  which  held  water  are  capable  of  breeding  both  mosquitoes  and 
 midges,  but  holes  containing  only  the  wet  soil  or  decaying  vrood  can  breed  blood- 
 sucking midges.   If  kerosene  or  other  surface-floating  oils  are  applied  to  rot  hole? 
 in  trees  for  mosquito  larvae,  the  midge  larvae  are  not  killed  by  the  treatment. 
 This  is  du.e  to  the  fact  that  midge  larvae  infest  wet  decayed  portions  of  the  trees 
 and  are  not  obliged  to  come  to  the  surface  of  the  water. 
 
 The  salt-marsh  sand  flies  do  not  develop  in  rot  holes  of  trees,  but  their 
 larvae  are  foxxnd  in  decaying  leaves  and  silt  along  the  edges  of  salt  marshes,  where 
 there  is  dense  shade  and  where  there  is  no  violent  daily  tidal  action.   Some  larvae 
 occur  in  crab  holes  of  seepage  areas  near  the  edges  of  the  marshes.   The  areas 
 which  produce  sand  flies  are  reached  by  salt  water  during  the  highest  tides  which 
 "spring"  up  about  once  each  month.  Since  the  larvae  require  about  5  months  or 
 longer  for  development  into  sand  flies,  it  is  practicable  co  direct  control  mea- 
 sures against  the  larvae  in  their  breeding  places.   If  trimming  the  trees  so  as  to 
 admit  sunlight  is  considered  undesirable,  the  shaded  areas  can  be  sprayed  with 
 creosoted  pine  sap.  _It^  should  be  us^d  at  the  rate  of  50  gallons  to  ^^00  sq\ 
 feet  of  marsh  1; 
 
3  1262  09223  0167 
 
 -   2  — 
 
 Breeding  areas  in  to7.TxS  and  cities,  where  the  n-unbor  of  people  affected  and 
 the  property  values  warrant   the  expense,    can  he  permanently  elimijia.ted  "by  hulk-  ^ 
 
 heading  and  filling. 
 
 Some  of  the  experiments  of  the  "B'iireati.  of  Entomology  arc  showing  that  drainage 
 ditches  designed  to  prevent  mosquito  "oreeding  in  salt  marshes  tend  to   concentrate 
 large  nijmhers  of  sand-fly  larvae  in  places  whel'e  many  of   then  are  killed  hy  drying 
 or  by  the  heat  of  the  sun.      It   seems  advisa'ble  to   supplement  such  a  natural  control 
 with  a  spray  treatment.      In  wet  ditches  and  along  their  oanks  in  salt  marshes  most 
 of   the  sand-fly  larvae  can  he  killed  "oy  spraying  with  creosote  oil  thinned  \7ith 
 kerosene,   or  hy  spraying  with  creosoted  pine  sap.     At  the  present  time   it  appears 
 that  one  treatment  during  the  autuirm  and  one  during  the   spring  months   should  ef- 
 fect a  high  degree  of   control. 
 
 In  a  small  experiment  at  Fort  pierce,   71a.  ,   the  Bureau  is  using  a  dike  to  im- 
 pound tidal  waters  on  a  mangrove  marsh.      The  capt-jred water  keeps  the  sand-fly  breed.* 
 ing  area  (consisting  of  salt   seepages)   submerged  so   that   send-fly  larvae  are  forced 
 to   the  edges  of  the  water.      The   soil  near  the  edges  of  the  water  is  being  sprayed 
 with  creosote  oil   thinned  with  kerosene.     This  diliing  and  flooding  experiment  appean 
 promising  for  control  of  mosquitoes  as  well  as  saiid  flies,  hccause  minnows   that  are 
 trapped  in  the   impotmdod  water  feed  upon  mosquito  larvae.      Such  a  control  method 
 promises  to  "be  helpful  also    in  reclaiming  a  marsh  by  allowing  the  impounded  area  to 
 collect   soil. 
 
 Sand-fly  breeding  near  small  streams  may  be  prevented  by  the  \ise  of   tide  gates 
 across  the   streams.     Such  gates  permit   the  fresh- water  streams   to  flow  durir:g  low 
 tides  but  automatically  close  during  the   rise  of  tidal  waters. 
 
 In  the  experience  of  this  hureau,   the  use  of  repellents  on  the  skin  and  on 
 window  screens  for  protection  against   sand  flies   is  not  very  satisfactory.      If  or- 
 dinary kerosene   is  applied  to   the  screens   it  keeps  some  of  the  flies  away  for  one 
 night.     An  application  of  pine  oil  is  more  satisfactory.      Sand-fly  annoyance   is  re- 
 duced if  the  use  ox   lights   in  bedrooms  is  avoided.     Some  oils  applied  to  the  skin 
 will  give  protection  for  30  minutes  to  an  hour  or  two.      The  oil  of  citronella  com- 
 monly employed  against  mosquitoes  is  not  as  effective  as  oil  of  camphor,   oil  of 
 sassafras,   or  oil  of  pine.      If  glycerine  is  applied  to   the  neck,  face,    and  h^nds 
 it   serves  as  a  mechanical  barrier  in  preventing  sand  flies  from  biting  and  taking 
 the  "blood  of  man.     As   a  lotion  to  relievo  burning  sensations  which  follow  the  bites 
 of   sand  flies,    5  percent  carbolic  acid  thoroughly  mixed  in  glycerine  may  "be  used. 
 
 Experiments  for  control   of   salt-marsh  sand  flies   are  being  carried  on  by  Dr. 
 W.   E.  Dove,   U.   S.   Bureau  of  Entomology,   403  P.   0.  Building,  Savannah,    Ga. 
 
 June  15.   1933.