Host range of a California sting nematode population

Abstract

Recently, sting nematodes were discovered associated with dying turfgrass in several golf courses in Coachella Valley, Calif. Based on their morphology and internal transcribed spacer (ITS) rDNA restriction pattern, the pests were identified as Belonolaimus longicaudatus Rau. This study was undertaken to determine the host status of 60 different plant species and cultivars for a California population of B. longicaudatus. The host range tests were conducted under greenhouse conditions at 25±2 °C and ambient light. At the second-leaf stage, each pot was infested with 55 ±12 adults or fourth-stage juveniles per 150 g of blow sand. The population densities determined after 7 weeks of incubation qualified >80% of the plants tested as good hosts with a reproduction factor (Rf = Pf/Pi) > 4. The majority of those were grasses, although reproduction was best on Gossypium hirsutum L. with Rf = 58.6. While Capsicum annuum L., Medicago sativa L., Arachis hypogaea L., Euphorbia glyptosperma Engelm., Cucumis sativus L., and Daucus carota L. were less suitable host plants with Rf < 4, only Abelmoschus esculentus (L.) Moench, Citrullus lanatus Thunb., and Nicotiana tabacum L. were nonhosts among the tested species. This sting nematode population had a high reproductive fitness on a majority of species tested and must be considered a major threat for most agricultural and horticultural crops grown in sandy soils.