Rice stem nematode - Ditylenchus angustus
EEffective: August 18, 2010 - December 31, 2020
Screening Aids:
Taxonomic Position:
Tylenchida : Anguinidae
Pest Type:
Nematodes
Pest Code (NAPIS):
NEKBBBC
| No manual – See Host Matrix |
These Approved Methods are appropriate for:
2020, 2019, 2018, 2017, 2016, 2015
Pest is vectored by:
This pest is is not known to be a vector and it is not vectored by any organism.
Survey
Approved Method(s):
| Method | Instructions | NAPIS Survey Method |
|---|---|---|
| Tissue Sample | See detailed survey instructions below. |
3011 - General Tissue Sample |
Survey Instruction Details:
Visual survey: symptoms of low infection are difficult to detect; to accurately assess or confirm infection it is necessary to sample tillers in the field. Tillers should be cut above the peduncle (the stalk bearing the inflorescence), because nematodes are not found in the internodes below the growing point.
1.Nematode collection: Collect nematodes by washing them off of plant material; nematodes can be easily extracted from plant pieces placed in a small container or Baermann funnel with water and left for 24 hours or overnight before examining material; rolled leaves or young inflorescence can be teased apart in a Petri dish or water and observed immediately for nematodes. A mist chamber can also be used for nematode extraction from plant tissue.
2.Sample submission: Submit samples to a nematology diagnostic lab for identification.
1.Nematode collection: Collect nematodes by washing them off of plant material; nematodes can be easily extracted from plant pieces placed in a small container or Baermann funnel with water and left for 24 hours or overnight before examining material; rolled leaves or young inflorescence can be teased apart in a Petri dish or water and observed immediately for nematodes. A mist chamber can also be used for nematode extraction from plant tissue.
2.Sample submission: Submit samples to a nematology diagnostic lab for identification.
Signs:
No specific signs are present.
Symptoms:
Infected plants with mottling arranged in a splash pattern; twisted leaves or panicles; panicles that fail to emerge or have sterile grain.
Key Diagnostics
ID/Diagnostic: Morphological
Morphological: Characteristics of males, females, and juveniles (Seshadri and Dasgupta, 1975; Mian and Latif, 1994; Das and Bajaj, 2008).
Mainly distinguished from other species based on tail shape and size, relative length of the stylet and post-vulval sac, and the number of cuticular lateral lines (Fortuner, 1982).
Mainly distinguished from other species based on tail shape and size, relative length of the stylet and post-vulval sac, and the number of cuticular lateral lines (Fortuner, 1982).
Mistaken Identities:
Damage and juvenile and female morphology are similar to that of Aphelenchoides besseyi.
In Progress / Literature-based Diagnostics:
Biochemical: Ibrahim et al. (1994a) used esterase and protein patterns to distinguish two species of Aphelenchoides from other Aphelenchoides species and from Ditylenchus angustus and D. myceliophagus.
Molecular: RFLP analyses have proven successful for distinguishing species of Ditylenchus (Wendt et al., 1993). PCR studies using a fragment of ribosomal DNA have also been used to separate D. angustus from Aphelenchoides (Ibrahim et al., 1994b).
Notes:
This nematode is a serious damaging pest of rice in the Far East and can be introduced with contaminated plant debris and soil.
D. angustus can increase the nitrogen content of rice plants and thus the plants become more susceptible to the plant pathogen Pyricularia oryzae (rice blast).
References
- Das, D., and Bajaj, H.K. 2008. Redescription of Ditylenchus angustus (Butler, 1913) Filipjev, 1936. Ann Pl. Prot. Sci. 16(1): 195-197.
- Fortuner, R. 1982. On the genus Ditylenchus Filpijev, 1936 (Nematoda: Tylenchida). Revue Nematol. 5(1): 17-38.
- Ibrahim, S.K., Perry, R.M., and Hooper, D.J. 1994a. Use of esterase and protein patterns to differentiate two new species of Aphelenchoides on rice from other species of Aphelenchoides and from Ditylenchus angustus and D. myceliophagus . Nematologia 40: 267-275.
- Ibrahim, S.K., Perry, R.N., Burrows, P.R., and Hooper, D.J. 1994b. Differentiation of species and populations of Aphelenchoides and of Ditylenchus angustus using a fragment of ribosomal DNA. Journal of Nematology 26(4): 412-421.
- Mian, I.H., and Latif, M.A. 1994. Ultrastructure and morphometrics of Ditylenchus angustus (Butler, 1913) Filipjev, 1936 (Nematodea: Anguinidae). Japanese Journal of Nematology 24: 14-19.
- Seshadri, A.R., and Dasgupta, D.R. 1975. Ditylenchus angustus. C.I.H. Descriptions of plant-pathogenic nematodes. Commonwealth Institute of Helminthology Set 5., No. 64.
- Wendt, K.R., Vrain, T.C., and Webster, J.M. 1993. Separation of three species of Ditylenchus and some host races of D. dipsaci by restriction fragment length polymorphism. Journal of Nematology 25(4): 555-563.