﻿between 
  species 
  of 
  Lema 
  and 
  Didbrotica. 
  369 
  

  

  Lema 
  Buckleyi, 
  Baly, 
  and 
  Diabrotica 
  elegans, 
  Baly, 
  

   both 
  from 
  Ecuador, 
  are 
  extremely 
  alike. 
  The 
  general 
  

   tone 
  of 
  colour 
  in 
  each 
  is 
  a 
  pale 
  yellow. 
  The 
  elytra 
  are 
  

   crossed 
  by 
  two 
  bright 
  metallic-blue 
  or 
  green 
  bands 
  — 
  one 
  

   at 
  the 
  base, 
  the 
  other 
  behind 
  the 
  middle. 
  These 
  bands 
  

   in 
  the 
  two 
  species 
  correspond 
  exactly 
  in 
  shape, 
  extent, 
  

   and 
  position. 
  Given 
  the 
  outline 
  of 
  one 
  species 
  to 
  fill 
  in, 
  

   and 
  the 
  other 
  species 
  as 
  a 
  model 
  from 
  which 
  to 
  copy, 
  it 
  

   would 
  be 
  difficult 
  for 
  an 
  artist 
  to 
  more 
  faithfully 
  repro- 
  

   duce 
  the 
  colours 
  and 
  design 
  than 
  Nature 
  has 
  done 
  in 
  

   this 
  case. 
  

  

  It 
  is 
  a 
  rather 
  happy 
  coincidence 
  in 
  nomenclature 
  that 
  

   the 
  same 
  specific 
  name 
  has 
  been 
  applied 
  to 
  a 
  Diabrotica 
  

   and 
  a 
  Lema, 
  both 
  from 
  Central 
  America, 
  and 
  both 
  

   closely 
  resembling 
  each 
  other. 
  This 
  name 
  — 
  biannidaris 
  

   — 
  pretty 
  well 
  expresses 
  the 
  character 
  common 
  to 
  the 
  

   two 
  species. 
  In 
  each 
  the 
  pale 
  yellow 
  elytra 
  carry 
  four 
  

   somewhat 
  circular 
  metallic-blue 
  figures. 
  The 
  two 
  basal 
  

   figures 
  are 
  usually 
  complete 
  circles, 
  the 
  two 
  posterior 
  

   figures 
  are 
  generally 
  cresceutic 
  or 
  arcuate 
  in 
  form. 
  

  

  Sufficient 
  has 
  been 
  stated 
  to 
  show 
  that 
  the 
  resemblances 
  

   are 
  not 
  confined 
  to 
  species 
  exhibiting 
  one 
  particular 
  kind 
  

   of 
  pattern, 
  but 
  that 
  almost 
  every 
  style 
  of 
  marking 
  

   occurring 
  in 
  the 
  genera 
  is 
  represented 
  among 
  the 
  imita- 
  

   tive 
  forms. 
  

  

  It 
  remains 
  for 
  me 
  now 
  to 
  offer 
  some 
  explanation 
  of 
  

   the 
  resemblances 
  here 
  recorded. 
  I 
  believe 
  they 
  are 
  

   cases 
  of 
  true 
  "mimicry"; 
  that 
  the 
  species 
  of 
  Diabrotica 
  

   are 
  protected, 
  and 
  that 
  the 
  species 
  of 
  Lema 
  derive 
  

   advantage 
  by 
  mimicking 
  them. 
  At 
  first 
  it 
  might 
  seem 
  

   that 
  the 
  Lemas, 
  owing 
  to 
  the 
  harder 
  covering 
  of 
  their 
  

   bodies, 
  were 
  the 
  protected 
  species, 
  and 
  that 
  the 
  softer- 
  

   bodied 
  Diabroticas 
  were 
  the 
  mimics, 
  just 
  as 
  certain 
  

   Longicorns 
  and 
  other 
  beetles 
  mimic 
  the 
  hard 
  Curcu- 
  

   lionidce. 
  But 
  the 
  following 
  considerations 
  will, 
  I 
  think, 
  

   bear 
  out 
  in 
  some 
  measure 
  the 
  opinion 
  which 
  I 
  have 
  

   expressed. 
  

  

  The 
  species 
  of 
  Diabrotica 
  are 
  very 
  numerous 
  in 
  in- 
  

   dividuals, 
  some 
  of 
  them 
  occurring 
  in 
  swarms 
  in 
  the 
  

   localities 
  in 
  which 
  they 
  are 
  found. 
  A 
  considerable 
  

   variety 
  of 
  colour 
  and 
  style 
  of 
  marking 
  runs 
  throughout 
  

   the 
  genus 
  Diabrotica. 
  This 
  is 
  true 
  also, 
  to 
  some 
  extent, 
  

   of 
  the 
  Lemas 
  of 
  America 
  ; 
  but, 
  as 
  a 
  rule, 
  the 
  Lemas 
  of 
  

   the 
  Old 
  World, 
  though 
  often 
  exhibiting 
  metallic 
  tints, 
  

  

  