Rev 11/19/2019
Dorylaimida Dorylaimina Dorylaimoidea Longidoridae Longidorinae
Longidorus elongatus (de Man, 1876) Micoletzky, 1922
Nematode is 4.5-6.4 mm long.
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Temperate regions; Britain, Europe, Canada, New Zealand, and U.S.
D-rated pests in California.
Ectoparasite on roots.
Strawberry, rye grass, carrots, peppermint.
Ecophysiological Parameters:
Nematode prefers coarse, well-drained soils.
Feeding causes galling of root tips and stunting of root system.
Photographs from Griffiths and Robertson (1984)
On Strawberry cultivar Redgauntlet on sandy soil in England, root growth was severely reduced, generally necrotic compared to healthy plants and lateral roots were short and swollen. Population levels in severely damaged areas were 10 nematodes per 10g soil. In the Netherlands, Seinhorst reported a tolerance limit of 1-5 individuals per 10 g soil on strawberry. In Scotland the concern is virus transmission rather than direct damage by the nematode (Graham and Flegg, 1968).
L. elongatus transmits raspberry ringspot and tomato blackring viruses.
L. leptocephalus, L. attenuatus, L. elongatus, Trichodorus spp. and viruses are involved in Docking Disorder of sugarbeets (named for Docking region in south of England); virus is carried on the inner surface of the stylet guiding sheath.
Stunted growth in spring due to nematode feeding; virus symptoms in foliage. Effects are most pronounced in spring, heavy rainfall in May seems to increase the problem. In July the affected plants start to grow again and may achieve almost normal foliage, but a much reduced tap root.
The severity of Docking Disorder varies from year to year with the climate.
Crop Rotation
Management of Docking Disorder by rotation is difficult as several nematode species are involved, each with a differing host range. Also host ranges of these nematodes are not completely known. Efficient rotation might be worked out on a local base according to the species present, but the prospects are not favorable because most of the species present are polyphagous.
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Nematicides
1,3-Dichloropropene (1,3-D) nematicide (400 lb/acre or 50 lb/acre on peppermint) applied in the plant row prior to planting reduces the nematode populations and increases yield, but only in well-drained alkaline soils. The treatment is not always effective at economically feasible rates (need high-value crops for cost-effective treatment).
CIH Descriptions of Plant-parasitic Nematodes, Set 2, No. 30 (1973)
Graham, C.W. and Flegg, J.M. 1968. Longidorus elongatus (de Man) Thorne & Swanger on strawberry (cultivar Redgauntlet). Plant Pathology 17:191.
Griffiths, B.S. and W.M. Robertson. 1984. Morphological and histochemical changes occurring during the lifespan of root-tip galls on Lolium perenne induced by Longidorus elongatus. J. Nematology 16:223-229.