Onchiostyle

An onchiostyle is a curved solid dorsal tooth (feeding spear) that extends from the anterior esophageal wall that is used during feeding. The onchiostyle is most commonly found in Trichodoridae nametodes.

Structure and components

The onchiostyle consists of two main parts:

Onchium: the curved solid tooth that punctures the plants.

Onchiophore: the supporting extension that holds the onchium.

The onchiostyle is slightly curved, solid at the tip, and lacks stylet knobs. It is usually considered a modified tooth rather than a hollow needle.

Examples and measurements

A couple of examples are the Trichodorus aequalis and the Trichodorus marylandi. The T. aequalis has an onchiostyle of 54 μm, and the T. marylandi has a onchiostyle of between 47 and 59 μm.

Function in feeding

The onchiostyle is used to puncture epidermal and sub-epidermal root cell, and also to inject salivary secretions.

References

↑ "Triplonchida". nemaplex.ucdavis.edu. Retrieved 2026-11-02.
↑ Karakas, Mehmet (2020). "Feeding structures and parasitic properties in plant-parasitic nematodes". Animals.
1 2 Helder, Johannes; Goverse, Aska (2017). "Parallel adaptations and common host cell responses enabling feeding of obligate and facultative plant parasitic nematodes". Animals.
↑ Decreamer, Wilfrida; Kantor, Mihail R; Handoo, Zafar A; Subbotin, Sergei A (2021). "Description of Trichodorus marylandi n. sp from Maryland, USA". Animals.
↑ Poudel, Dinesh; Yan, Guiping (2025), Amaresan, Natarajan; Kumar, Krishna (eds.), "Trichodorus and Paratrichodorus", Compendium of Phytopathogenic Microbes in Agro-Ecology : Vol. 3, Bacteria, Protozoa, Algae and Nematodes, Cham: Springer Nature Switzerland, pp. 597–611, doi:10.1007/978-3-031-81999-5_30, ISBN 978-3-031-81999-5, retrieved 2026-11-02{{citation}}: CS1 maint: work parameter with ISBN (link)

[1] "Triplonchida". nemaplex.ucdavis.edu. Retrieved 2026-11-02.

[2] Karakas, Mehmet (2020). "Feeding structures and parasitic properties in plant-parasitic nematodes". Animals.

[HelderGoverse2017-1-3] 1 2 Helder, Johannes; Goverse, Aska (2017). "Parallel adaptations and common host cell responses enabling feeding of obligate and facultative plant parasitic nematodes". Animals.

[4] Decreamer, Wilfrida; Kantor, Mihail R; Handoo, Zafar A; Subbotin, Sergei A (2021). "Description of Trichodorus marylandi n. sp from Maryland, USA". Animals.

[5] Poudel, Dinesh; Yan, Guiping (2025), Amaresan, Natarajan; Kumar, Krishna (eds.), "Trichodorus and Paratrichodorus", Compendium of Phytopathogenic Microbes in Agro-Ecology : Vol. 3, Bacteria, Protozoa, Algae and Nematodes, Cham: Springer Nature Switzerland, pp. 597–611, doi:10.1007/978-3-031-81999-5_30, ISBN 978-3-031-81999-5, retrieved 2026-11-02{{citation}}: CS1 maint: work parameter with ISBN (link)