Drosophila buzzatii 12 Drosophila koepferae 12 Trichocereus terschekii Cactaceae 10 Opuntia sulphurea 10 Animals 8 Cactophilic Drosophila 8 Drosophila 8 Opuntia 8 article 8 body size 8 fly 8 Body size 6 Host plants 6 Species Specificity 6 animal 6 host plant 6 interspecific variation 6 species difference 6 Diptera 4 Drosophilidae 4 Environmental heterogeneity 4 Habitat selection 4 Morphogenesis 4 Opuntia quimilo 4 Wing 4 Wing morphology variation 4 adaptation 4 breeding 4 forelimb 4