Species richness of arachnids associated with Protea nitida (Proteaceae) in the Cape fynbos.

Regular counts of Arachnida on Protea nitida Mill. were made in three study areas in the western Cape over a period of one year. They were also invest igated in the rest of the natural distribution area of I! nitida in the sou thern and western Cape, Collections were made according to three standardiz ed methods. Five arachnid orders were collected, of which the araneae (spid ers) were dominant. Thirty-two spider species (653 individuals) representin g 18 families were collected, of which five families and eight genera (eigh t species) were recorded for the first time on the Proteaceae in the Cape f ynbos. Four non-Araneae orders were collected. A micro-habitat preference w as observed in some families. Numbers of immature spiders peaked in autumn. Adults and immatures did not always have the same habitat distribution and did not always peak during the same season. Families also showed differenc es in seasonal abundance. Plant architecture and distribution influenced th e number of species collected. Protea nitida hosted more spider species tha n less complex plants with smaller distributions. The implications of these findings are discussed in terms of biodiversity and invertebrate conservat ion.