Sting nematode management in Florida strawberry.

Strawberry (Fragaria × ananassa) is an economically important fruit crop for the United States, with a total production of 1.3 million tonnes across 20,000 ha in 2018. Florida produces 15% of the total strawberry produced in the US. The most economically important nematode pest of Florida strawberry is the sting nematode (Belonolaimus longicaudatus), and occasionally the root-knot nematode (Meloidogyne hapla) or strawberry crimp nematode (Aphelenchoides besseyi) when introduced within bare-root strawberry transplants from US or Canadian nurseries. This chapter discusses the economic importance, distribution, host range, damage symptoms, and recommended integrated management of B. longicaudatus. Future research requirements and future developments are also mentioned.

Distribution of southern sting nematode, Ibipora lolii (Nematoda: Belonolaimidae), on turfgrass in Australia and its taxonomic relationship to other belonolaimids

Molecular evidence from sequences of three regions of ribosomal DNA (partial SSU, ITS-1, 5.8S and ITS-2, and D2/D3 expansion segments of LSU) is presented to show that the two belonolaimids described from turfgrass in Australia (Ibipora lolii and Morulaimus gigas) are identical. Morulaimus gigas is therefore considered a junior synonym of I. lolii. The decision to place the nematode in Ibipora rather than Morulaimus is supported by molecular studies which showed that I. lolii is not closely related to Morulaimus or Carphodorus, two belonolaimid genera that are only found in Australia. Survey data are presented to show that I. lolii is widespread on turfgrass around Newcastle in New South Wales and in Perth, Western Australia, where the infested area is increasing rapidly, largely because the nematode is being spread in planting material. Ibipora lolii damages all turfgrass species but is particularly damaging to kikuyu grass (Pennisetum clandestinum), the main grass used for sporting fields and recreational areas in warm regions of Australia. Data from an experiment in pots also show that the nematode multiplies to damaging levels on sugarcane. Symptoms on grasses are similar to those caused by the sting nematode, Belonolaimus longicaudatus, in south-eastern USA, but because the two nematodes are taxonomically different, I. lolii is referred to as the southern sting nematode. Ibipora lolii was not found in surveys of natural vegetation on the east and west coasts of Australia, suggesting that it is an introduced species, possibly originating in South America or the Caribbean, where other Ibipora species are found.

Taxonomy and morphology of plant-parasitic nematodes associated with turfgrasses in North and South Carolina, USA

Twenty-nine species of plant-parasitic nematodes were recovered from 282 soil samples collected from turfgrasses in 19 counties in North Carolina (NC) and 20 counties in South Carolina (SC) during 2011 and from previous collections. These nematodes belong to 22 genera in 15 families, including Belonolaimus longicaudatus, Dolichodorus heterocephalus, Filenchus cylindricus, Helicotylenchus dihystera, Scutellonema brachyurum, Hoplolaimus galeatus, Mesocriconema xenoplax, M. curvatum, M. sphaerocephala, Ogma floridense, Paratrichodorus minor, P. allius, Tylenchorhynchus claytoni, Pratylenchus penetrans, Meloidogyne graminis, M. naasi, Heterodera sp., Cactodera sp., Hemicycliophora conida, Loofia thienemanni, Hemicaloosia graminis, Hemicriconemoides wessoni, H. chitwoodi, Paratylenchus goldeni, Xiphinema americanum sensu lato, X. bakeri, X. chambersi, Longidorus paralongicaudatus, and Aphelenchoides myceliophagus. Eleven species (Meloidogyne graminis, M. naasi, Cactodera sp., Pratylenchus penetrans, Hemicycliophora conida, Hemicaloosia graminis, Mesocriconema xenoplax, M. sphaerocephala, Ogma floridense, Paratrichodorus allius, Dolichodorus heterocephalus) were new records from turfgrass in both states; five (Heterodera sp., Loofia thienemanni, M. curvatum, Longidorus paralongicaudatus, Filenchus cylindricus) were new in SC; and three (Hemicriconemoides wessoni, Xiphinema bakeri, Aphelenchoides myceliophagus) were new in NC. The morphological and morphometric characteristics of these species are presented.

Screening Bermudagrass Germplasm Accessions for Tolerance to Sting Nematodes

Breeding and improvement of new bermudagrass (Cynodon spp.) cultivars with superior nematode tolerance are essential because sting nematode (Belonolaimus longicaudatus Rau) is a major limitation for use of bermudagrass in the sandy coastal soils of the southeastern United States. The screening of both African (Cynodon transvaalensis) and common (C. dactylon) bermudagrass is necessary to develop triploid hybrid cultivars. Five commercial cultivars and 46 germplasm accessions of bermudagrass were tested for nematode responses in two greenhouse trials in 2009. Turfgrass was grown in sand-filled plastic conetainers and inoculated with 50 sting nematodes per conetainer. Nematode and root samples were collected 90 d after nematode inoculation. Fifteen bermudagrass accessions did not have measurable root loss from inoculation with sting nematode. Seven bermudagrass accessions, including ‘Celebration’, produced longer roots in sting nematode-infested soil than the standard ‘Tifway’. Differences in final nematode numbers were identified among the genotypes, and different relative responses were identified in variable ploidy levels and origins. This could aid a turfgrass breeding program by elucidating the genetic diversity available for breeding future bermudagrass cultivars for golf course cultivation.

First Report of the Sting Nematode Belonolaimus longicaudatus on Soybean in Delaware

In late July of 2005, several, large, irregular areas of severely chlorotic, stunted, and dead soybean plants were observed in two fields of soybean (Glycine max), 8.05 km apart, in sandy soil (94% sand, 2% silt, and 4% clay) in southwestern Sussex County, DE. The grower also had observed stunted corn the previous year in the same areas and thought the fields had a fertility problem. The morphology of adults and molecular analyses of the juveniles isolated from soil samples established the identity of the species as the sting nematode, Belonolaimus longicaudatus (1–4). The population density was 216 nematodes per 250 cm3 of soil. Morphological characters used for identification included female body, stylet and tail length, shape of head, stylet knobs, tail and tail terminus, number of lines in the lateral field, and vulva percentage in relation to body length. The male characters critical for identification were the following: body, stylet, spicule, and gubernaculum length; shape of head and stylet knobs; and number of lines in the lateral field. Measurements of females (n = 5) included body length (range = 2,035 to 2,120 μm, mean = 2,073.7, standard deviation [SD] = 37.0), stylet (117.0 to 127.5, 123.4, 4.5), V% (48.4 to 52.3, 50.6, 1.5), and tail (109 to 140, 120, 14.2). The lateral field had one incisure. Shape of head, stylet knobs, and tail were also consistent with B. longicaudatus. Males (n = 4) were characterized by the body length (range = 1,500 to 2,070 μm, mean = 1,753.3, SD = 290.2), stylet (117.0 to 127.5, 121.5, 5.4), spicules (41 to 50, 47, 5.2), and gubernaculum (17.0 to 18.5, 17.8, 0.8). Molecular diagnosis as B. longicaudatus was confirmed by sequencing two ribosomal DNA markers from three juveniles. Sequence of the internal transcribed spacer region ITS1 and 2 (GenBank Accession No. GQ896549) from this population was 99% identical to Florida isolate BlCi6 (DQ672368), and the 28S large ribosomal subunit D2-D3 expansion region (GQ896548) was 99% identical to Florida isolate BlCi4 (DQ672344). A high degree of similarity (>98%) was also shared by several other B. longicaudatus sequences (1). This detection represents a new state record in Delaware for B. longicaudatus. Since this detection in 2005, there have been no new reports of other observations of sting nematode or spread from these two fields tilled by the same farm operator in Delaware. Elsewhere, B. longicaudatus is known to occur in subtropical regions of the lower coastal plain, from Virginia to Florida and along the Gulf Coast into Texas. On the east coast, USDA Nematode Collection records document this nematode from Florida, Georgia, New Jersey, and South Carolina. Within Delaware, another sting nematode species, Belonolaimus maritimus, was detected on American beachgrass (Ammophila breviligulata) and bitter panicgrass (Panicum amarum var. amarulum) from Fenwick Island, near the Maryland border. Sting nematodes have also been reported in Burlington County, NJ. References: (1) U. Gozel et al. Nematropica 36:155, 2006. (2). H.-R. Han et al. Nematropica 36:37, 2006. (3) G. J. Rau. Proc. Helminthol. Soc. Wash. 25:95, 1958. (4) G. J. Rau. Proc. Helminthol. Soc. Wash. 30:119, 1963.