ADAPTATION OR COEVOLUTION IN ASSOCIATIONS OF PHYTOPHAGOUS ENDEMIC BUGS AND VASCULAR PLANTS ON THE CANARY-ISLANDS (HETEROPTERA)

A tentative analysis of the trophic behaviour of the 335 species of He teroptera, hitherto known from the Canary Islands, leads to the conclu sion that 247 species (nearly 74%) are predominantly phytophagous, 80 spp (24%) are carnivorous and 8 spp are ambivalent in their feeding ha bits. About 1/3 (105 spp) of these Heteroptera species are regarded as Canarian or Central-Macaronesian endemics (ie: also occurring on Made ira). 78% of these endemic ones (79 terrestrial spp, 3 aquatic spp) ar e herbivores and 22% (23 spp) are carnivores. There is a significant c orrelation between endemic herbivorous Heteroptera and endemic vascula r plants: 22 spp only feed on endemic plants, 19 spp on endemic and no n-endemic plants, although no clear association can yet be stated for the remaining ones. The question wether these insect-plant specialisat ions result from adaptive and/or coevolutionary processes is discussed , but cannot be decided unless more experimentally proved data are ava ilable.