COMPARATIVE LIFE-HISTORIES AND PREDATION TYPES - ARE NEOSEIULUS-CALIFORNICUS AND NEOSEIULUS-FALLACIS (ACARI, PHYTOSEIIDAE) SIMILAR TYPE-II SELECTIVE PREDATORS OF SPIDER-MITES

Both Neoseiulus californicus (McGregor) and N, fallacis (Garman) have been rated a type II selective predator of spider mites that feeds mor e on spider mites than pollen or insects. We assessed this predation r ating or an alternative hypothesis that N. californicus is more of a g eneralist predator than N.fallacis. In tests, reproduction was equal o r greater for hi californicus than N. fallacis when each was held sepa rately with excess Tetranychus urticae Koch, Panonychus ulmi (Koch), F rankliniella occidentalis (Pergrande), or maize pollen, but it was les s when with Aculus schlectendali Nalepa or Oligonychus ilicis (McGrego r).A! californicus had other traits more like those of a generalist pr edator-adult females had shorter dorsocentral setae and moved farther on a plant but less often and for less distance between plants. N. cal ifornicus nymphs fed more either intraspecifically and interspecifical ly on phytoseiid eggs, but adult females of both species fed similarly on eggs of either phytoseiids. Larval feeding was less for N, califor nicus but nymphal feeding drive was alike for both species. Of 17 trai ts that were tested, 11 indicated more of a generalist role for N. cal ifornicus; 6 traits did not differ between species, and none indicated that N. californicus was more of a specialist predator of spider mite s than hi fallacis. N.fallacis clearly is a specialist type II species , but a rating between specialist II and generalist III is needed for N. californicus. Traits of immatures were more discriminating than tra its of female adults in this study; both trait types should be include d in predation rating systems.