OCCURRENCE OF PASTEURIA-LIKE ORGANISMS ON SELECTED PLANT-PARASITIC NEMATODES OF PINEAPPLE IN THE HAWAIIAN-ISLANDS

Soils from 320 sites representing diverse undisturbed habitats from fi ve Hawaiian Islands were assessed for occurrence of Pasteuria-like org anisms. Mean annual rainfall at sites ranged from 124-350 cm, elevatio n from 69-2,286 m, and annual mean temperature from 12-24 C. Seven dif ferent natural communities were represented: wet lowland, mesic lowlan d, wet montane, mesic montane, dry montane, mesic subalpine, and dry a lpine. Pasteuria spp. in a soil sample was detected by baiting with in fective stages of Helicotylenchus dihystera, Meloidogyne javanica, Pra tylenchus brachyurus, and Rotylenchulus reniformis, followed by cultiv ation of the nematodes on pineapple plants for 10-11 months. All nemat ode baits except R. reniformis were readily recovered from the soil sa mples. A sample was considered Pasteuria-positive if at least 5% of th e nematode specimens showed endospore attachment. Thirteen percent of all samples were positive for Pasteuria-like organisms. The frequencie s of association between Pasteuria spp. and Meloidogyne, Helicotylench us, or Pratylenchus species were 52%, 24%, and 24%, respectively. Posi tive samples were more prevalent on the older islands of Kauai and Oah u (75%), in lowland communities (61%), and in areas with introduced ve getation (60%). More than 27% of the positive samples were associated with plant species in a few selected families that included Meliaceae and Myrtaceae. Occurrence of Pasteuria spp. seemed to be positively as sociated with mean annual rainfall or temperature, but negatively asso ciated with elevation.