463 
On  one  occasion  over  twenty  individuals  were  counted  while  they 
were  frequenting  the  carcase  of  a  mongoose.  They  seemed  equally 
common  during  December  and  January.  Like  the  allied  European 
Lucilia  serricata,  which  it  much  resembles  in  habits,  it  evidently 
passes  its  larval  stage  usually  in  putrid  carcases,  but,  unlike  the  latter, 
it  also  infests  man  as  well  as  his  domesticated  animals.  Fortunately 
for  Jamaica  the  John  Crows  [Catharies  aura)  remove  practically 
all  traces  of  carrion  from  man’s  habitation,  and  in  this  way,  no  doubt, 
very  materially  check  the  increase  of  this  pest. 
The  fly  may  be  readily  recognised  by  the  following  characteristics  : 
Female.  Face  and  jowls  testaceous,  the  latter  clothed  with  long 
golden  hairs ;  cheeks  golden  yellow.  Third  segment  of  antennae 
smoky  brown,  basal  segments  paler.  Eyes  red-brown,  widely 
separated.  Thorax  brilliant  metallic  grey-green  with  three  broad, 
equidistant,  black  stripes  having  bluish  reflections ;  scutellum  bronzy- 
greenish  blue.  Abdomen  bronzy  green  with  bluish  reflections.  Legs 
black.  Length,  6  to  9  mm  ;  expanse  of  wing,  9  to  1 7  mm. 
Male.  Similar  but  smaller,  and  the  eyes  almost  meet  in  the 
median  line. 
HORN  FLY 
Lyperosia  irritans,  Linn. 
This  is  the  small  black  fly  which  is  known  in  the  United  States 
as  the  '  Horn-Fly,’  so  named  because  of  its  peculiar  habit  of  clustering 
in  masses  about  the  bases  of  the  horns  of  cattle.  Howard,*  who  has 
given  a  very  interesting  account  of  the  habits  and  life-cycle  of  the 
insect,  points  out  that  there  is  no  foundation  for  the  belief  that  it 
damages  the  horn  by  eating  into  it  or  causing  it  to  decay.  Curiously, 
this  extraordinary  habit  does  not  obtain  in  England,  nor,  so  far  as 
the  writer’s  experience  goes,  does  it  in  certain  portions  of  the 
Continent  of  Europe ;  and  the  few  examples  which  the  writer 
saw  in  Jamaica  certainly  did  not  resort  to  the  horns  of  cattle  as  a 
resting  place.  Howard  discovered  for  the  first  time  that  the 
eggs  are  laid  in  freshly  dropped  dung  and  that  the  whole 
cycle  occupies  about  a  fortnight.  Although  the  writer  has  had 
abundant  opportunities  for  the  study  of  the  life-cycle  in  England,  he 
*  Insect  Life,  Vol.  11,  p.  i. 
