OVIPOSITION AND PERFORMANCE IN NATURAL HOSTS IN CACTOPHILIC DROSOPHILA

SOTO, E, J GOENAGA, JP HURTADO & E HASSON

EVOLUTIONARY ECOLOGY

SPRINGER

Lugar: New York; Año: 2012 vol. 26 p. 975 - 990

0269-7653

he  cactus-­‐yeast-­‐Drosophila  model  system  provides  an  excellent  opportunity  to  investigate   the  significance  of  ecological  factors  in  evolution.  The  South  American  D.  buzzatii  and  D.  koepferae  are   two  closely  related  sibling  species,  with  partially  overlapping  distribution  ranges  and  a  certain  degree   of  niche  overlap.  The  main  breeding  and  feeding  resources  of  D.  buzzatii  are  the  decaying  cladodes  of   prickly  pears  (genus  Opuntia),  whereas  D.  koepferae  utilizes  mainly  columnar  cacti  of  the  g enera   Cereus  and  Echinopsis.  These  host  plants  differ  in  their  chemical  composition,  the  microflora   associated  to  the  decaying  process  and  patterns  of  spatial  and  temporal  predictability.  The  aim  of  this   work  is  to  investigate  host  plant  selection  and  utilization  of  two  different  cactus  hosts.  We  report  the   results  of  field  and  laboratory  studies  examining  behavioral  traits  related  to  egg -­‐laying  (oviposition   preference  and  host  acceptance)  and  several  measures  of  performance  (viability,  developmental  time,   wing  morphology  and  starvation  resistance)  in  flies  reared  in  the  two  main  host  cacti  that  D.  koepferae   and  D.  buzzatii  exploit  in  the  studied  area:  O.  sulphurea  and  E.  terschekii.  The  main  conclusion  of  the   assessment  of  the  distribution  of  adult  flies  in  relation  to  the  abundance  of  the  host  plants,  attraction  to   and  emergence  from  substrates  of  both  host  plants,  larval  and  adult  fitness  performance  and   behavioral  traits  is  the  remarkable  influence  that  cactus  hosts  impose  on  the  life  history  of  the   cactophilic  sibling  species  D.  buzzatii  and  D.  koepferae.