Nematology 100: LECTURE 6

Rev. 10/14/2008

Nematodes Parasites of Higher Plants

Migratory Ectoparasites - Criconematoidea

Criconematoidea

• procorpus amalgamated with median bulb.

• migratory - true ectoparasites.

Criconematinae:

    Criconemoides, Criconema, Hemicriconemoides:

• thick cuticle with strong retrorse annulation or double cuticle

• isthmus broad, anchor-shaped stylet knobs

Hemicycliophorinae:

    Hemicycliophora

• large nematode, up to 2mm

• extra cuticle or sheath

• male without stylet, curved spicules, prominent bursa

Paratylenchinae:

    Paratylenchus, Gracilacus

• cuticle finely annulated

• female stylet slender, male stylet reduced or absent.

• isthmus distinct and slender

• no sheath

• 4th stage dauer/survival stage.

All these nematodes are or have:

    1. Relatively sedentary

    2. Long stylets - deeper feeding

    3. Single ovary - compare with Belonolaimidae, Dolichodoridae, Hoplolaimidae.

    4. Reduced males, probably not feeding, rare in some cases.

    5. Relationship to plant vigor

        Predisposition: e.g. Bacterial canker complex - effects, factors involved

Superfamily:  Criconematoidea

Family Criconematidae

        Subfamily Criconematinae

                  Criconemoides xenoplax

                            Hemicriconemoides

Subfamily: Hemicycliophorinae

Hemicycliophora arenaria

Family Tylenchulidae

Subfamily Paratylenchinae

Paratylenchus hamatus

 

Slides: on migratory ectoparasites