Plant patch structure modifies parasitoid assemblage richness of a specialist herbivore

FENOGLIO, M. S.; SALVO, A.; VALLADARES, G.; VIDELA, M.

ECOLOGICAL ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 35 p. 594 - 601

0307-6946

1.  The  spatial  structure  of  plant  patches  has  been  shown  to  affecthost?parasitoid interactions, but its influence on parasitoid diversity remains largelyignored. Here we tested the prediction that parasitoid species richness of the specialistleafminer Liriomyza commelinae  increases in larger and less isolated patches of itshost  plant  Commelina erecta.  We  also  explored  whether  parasitoid  abundance  andbody size affected the occurrence of parasitoid species in local assemblages.2. A total of 893 naturally established C. erecta patches were sampled on 18 sitesaround C´ordoba city (Argentina). Also, two experiments were performed by creatingpatches differing in the number of plants and the distance from a parasitoid source. Forthese tests, plants were infected with the miner in the laboratory prior to placementin the field.3. Plant patch size, independently of host abundance, positively affected the numberof  parasitoid  species in  both  survey observations and experimental data. However,plant patch isolation did not influence parasitoid species richness.4.  The  probability  of  finding  rare  parasitoid  species  increased  with  patch  size,whereas occupation of isolated patches was independent of dispersal abilities (bodysize) of parasitoid species.5. Overall, the results highlight the importance of considering spatial aspects suchas the size of plant patches in the study of parasitoid communities.