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Pest Description
IDENTITY: Scientific name: Thecavermiculatus andinus
Golden, Franco, Jatala & Astogaza, 1983
 Common name: A cystoid nematode

NOTES ON TAXONOMY AND BIOLOGY:  Thecavermiculatus andinus is a non-cyst forming heteroderid, which belongs to the subfamily Ateloderinae. Swollen females of this cystoid nematode lack annulate cuticle; vulva and anus located at the terminal posterior end of the body lacking a protuberance. The distance between vulva and anus is greater than that of other species of the genus and are about 59 µm. For this reason, the taxonomic position of T. andinus is still controversial and this species may prove to be a separate genus (Baldwin and Mundo Ocampo, 1991). Swollen females retain the eggs, which hatch quickly inside the female body at the end of the reproductive cycle. Second-stage juveniles (J2) emerge from the female body, penetrate host roots and establish a specialized feeding site (syncytium) in the stele. They develop and become swollen round to oval females. Females rupture root cortex and protrude from root surface  (Baldwin and Mundo Ocampo, 1991; Golden et al., 1983; Wouts, 1972).

GEOGRAPHICAL DISTRIBUTION:  Thecavermiculatus species evolved on the American continent. T. andinus is a South American species occrring in  the highland Andean region of southern Peru. Specimens of this species were also collected in Chile.

HOSTS: This heteroderid reproduces on the following agronomic crops and weeds: bur clover (Medicago hispida), false mallow (Malvastrum coromandelianum), egg plant (Solanum melogena), lupin (Lupinus mutabilis), oca (Oxalis tuberosa), potato (Solanum tuberosum sbsp. andigena), quinoa (Chenopodium quinoa), shepherd’s purse (Capsella bursa-pastoris), and ulluco (Ullucus tuberosum).

CROP LOSSES: The crop loss induced by T. andinus on potato and other tuber crops has not been quantified (Jatala and Bridge, 1990).

MEANS OF MOVEMENT AND DISPERSAL: This nematode is spread through soil debris, and by infected propagative plant material and edible roots or tubers.

RATING: (L) Taking into consideration the limited chance of introduction of this nematode from the Andean regions of Peru, a low priority rating was given to this nematode for a complete risk assessment.

    Baldwin, J.G., and M. Mundo-Ocampo. 1991. Heteroderinae, cyst and non-cyst-forming nematodes. Pp. 275-362 in W. R. Nickle ed. Manual of agriculture nematology. New York: Marcel Dekker Inc.
    Golden, A. M., J. Franco, P. Jatala, and E. Astogaza. 1983. Description of Thecavermiculatus andinus n. sp. (Heteroderidae), a round cystoid nematode from Andes mountains of Peru. Journal of Nematology 15:357-363.
    Jatala, P., and J. Bridge. 1990. Nematode parasites of roots and tuber crops. Pp.137-180 in M. Luc, R. A. Sikora, andd J. Bridge eds. Plant parasitic nematodes in tropical and subtropical agriculture. Wallingford, UK: CAB International.
    Wouts, W. M. 1972. A revision of the family Heteroderidae (Nematoda: Tylenchoidea) I. The family Heteroderidae and its subfamilies. Nematologica 18:439-446.