Biological notes on the spiders of some citrus groves in central and southern California

This list of the spider species found in several citrus groves in central and southern California is supplemented with biological notes on the more abundant species. Spiders outnumbered all other large predators in the citrus canopy and were abundant in the litter. Oxyopes scalaris (Oxyopidae), Thiodina cf. T. sylvana (Salticidae), Misumenops spp. (Thomisidae) and Trachelas pacificus (Clubionidae) were the most abundant vagrant spiders in the canopy. The diet of these spiders is discussed, with emphasis on the spiderlings. Abundant web-building spiders in the canopy were typically small-sized species. These included Theridion leechi (Theridiidae), Erigone dentosa (Linyphiidae) and Dictyna reticulata (Dictynidae). Hololena spp. (Agelenidae) were the only abundant web-building large spiders. Sac spiders (Clubionidae) are probably the most promising natural enemies of citrus pest arthropods.