Arthropod diversity in necrotic tissue of three species of columnar cacti (Cactaceae)

We compared the insect and arachnid species found in spring and summer samp les of necrotic tissue of three species of columnar cacti, cardon [Pachycer eus pringlei (S. Watson) Britten and Rose], organ-pipe (Stenocereus thurber i Buxb.), and senita [Lophocereus schottii (Engelm.) Britten and Rose] (all Cactaceae), endemic to the Sonoran Desert of North America. A total of 938 0 arthropods belonging to 34 species, 23 families, 10 orders, and 2 classes were collected in 36 samples. Arthropod communities differed in compositio n among host cacti, as well as between seasons. These differences may be a function of variation in host characteristics, such as chemical composition and abiotic factors, such as water content or temperature.