Small stem
| Small stem | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ditylenchus dipsaci | ||||||||||||
| ( Kühn , 1857) |
The Ditylenchus dipsaci , Kleeälchen or eelworm ( Ditylenchus dipsaci ) is a type of nematodes (Nematoda), as pest on various crop plants, such as potato , the tobacco and sugar beet occurs.
features
The small stem is a slender, almost transparent nematode. Both sexes reach a length of about 1.2 millimeters. At field beans particularly large specimens occur length of up to two millimeters. The flanks are divided into four fields, the tail end is pointed. The spiculum in the male is about 10 to 12 µm long and thickened at the base. The female post-vulval sac extends about half the way to the anus .
biology
During all stages of development, overwintering takes place on the host plants or on plant residues or waste (e.g. beet residues). They can survive in the ground for several years. Larvae and adults enter the host through stomata or injuries. The stem elbows feed on the cell sap, which they suck up with their mouth sting (stylet) after the secretion of salivary enzymes. Toxic components of their saliva cause necrosis and, through the dissolution of the central lamellae of cell associations, distortion of the tissue.
Symptoms
- Potato: The first symptoms are thickening on the stems of young potato plants. Later the leaf stalks thicken and become hard and brittle. The internodes remain short, the leaves small and misshapen. Spots will appear on the tubers and their skin may tear. Inside the tuber, the damaged areas appear like a cone.
- Beet: Beet head rot can be seen on beet with significant scab-like cracks and rot on the beet head.
- Maize: The so-called falling sickness occurs, which negatively affects the stability of the maize plant.
literature
- Horst Börner: Plant diseases and plant protection. 7th edition, UTB 518, Verlag Eugen Ulmer, Stuttgart.
- R. Bovey: La défense des plantes cultivées. 6ème édition, Payot Lausanne, 1972.
- EPPO quarantine pest: Data Sheets on Quarantine Pests: Ditylenchus dipsaci ( PDF ).