SPECIES COMPOSITION, ABUNDANCE, AND ACTIVITY OF PREDATORY ARTHROPODS IN CARROT FIELDS, CANTERBURY, NEW-ZEALAND

Pitfall trapping (November 1993 to April 1994) and Malaise trapping (J anuary to June 1995) were carried out to study the predatory arthropod fauna in carrot fields at four sites in Canterbury, New Zealand. Stap hylinidae (rove beetles), Linyphiidae (money spiders), Lycosidae (wolf spiders), Phalangiidae (harvestmen), and Carabidae (ground beetles) w ere the most abundant predators. At Lincoln, spiders, staphylinids, ha rvestmen, and carabids comprised 68, 13, 11, and 2.6 percent, respecti vely, of all total predaceous arthropods in pitfall traps. At Killinch y (30 km from Lincoln) these four taxa constituted 77, 8.5, 0.7, and 6 .5 percent of the pitfall trap catches. Overall, a total of 33 staphyl inid species was recorded, including one, Ocypus ater (Gravenhorst), w hich was new to New Zealand. The total number of predators caught in p itfall traps declined in March and April. In pitfall traps the abundan t species were the staphylinids Amischa analis (Grav.), A. nigrofusca (Step.), Atheta fungi (Grav.), A. amicula (Step.), and Xantholinus lin earis (Oliver); the carabids Metaglymma monilifer Bates and Holcaspis angustula Chaudoir; the spiders Lepthyphantes tenuis (Blackwall), Erig one spp. and 'Lycosa' hilaris Koch; and the harvestman Phalangium opil io L. In Malaise traps, abundant staphylinid species were Tachyporus n itidulus (Fab.), Amischa decipiens (Sharp), and Atheta fungi (Grav.). The seasonal activity and abundance of the dominant species are descri bed, and their potential importance in control of carrot rust fly (Psi la rosae F.) and pests in other crops is discussed.