NOTES ON TAXONOMY AND BIOLOGY: This amphimictic nematode is morphologically similar to H. gracilis. Morphological differences of females include a more rounded head, which is flattened in H. gracilis, smaller b’values (3.8-4.8 vs 5.3-8.7), and a longer non-annulated portion of the tail terminus. This species has migratory endoparasitic habits. Nematode development and reproduction occurs inside the root of the plant host.

GEOGRAPHICAL DISTRIBUTION:  H. miticausa is a tropical species occurring in Papua New Guinea and Salomon Islands (CAB Intrnational, 2001).

HOSTS: Taro (Calocasia esculenta) is the only known host of this species.

CROP LOSSES: Nematode damage is serious and results in corm rots and decay of infected taro plants. The syndrome induced by the nematode is called  “mitimiti’ and is accentuated by concomitant infection by fungi such as Fusarium solani and Pythium vexans (Bridge et al., 1983).

MEANS OF MOVEMENT AND DISPERSAL: Through root material and by infected bare root propagative plant material.

RATING: (VL) Due to the limited distribution and host range of the nematode, and the low chancess of introduction into the United States, the risk that it poses to the US is rated very low by the committee.

REFERENCES:
    Bridge, J.,  J. J. Mortimer, and V. H. Jackson. 1983. Hirschmanniella miticausa n. sp. (Nematoda: Pratylenchidae) and its pathogenicity on taro (Calocasia esculenta). Revue de Nématologie 6:265-290.
    CAB International, 2001. Hirschmanniella miticausa in: Crop protection compendium, global module, 3rd edition. Wallingford, UK: CAB International.