First record of the persian sessile nematode Cacopaurus pestis in Iran

Abstract

The plant parasItIc nematode Cacopaurus pestis Thorne, the only known species in the genus, was first described by Thorne 1943 on Persian walnut (Juglans regia L.). He considered it to be a monophagous species and an important root pathogen. The unique relationship of this nematode to Persian walnut stimulated the use of the trivial name « Persian sessile nematode ». C. pestis, however, has never been recorded from Iran or from any other country in Asia. The use of inappropriate extraction methods, the small size of the nematode, and its sedentary form of parasitism are reasons why it has been only rarely found. The nematode has been recorded only from California, USA (Thorne, 1943), southern France (Scotto la Massese, 1971), Italy (Inserra, 1973) and Spain (Bello and Belart, 1975). Besides Persian walnut, the only other known hosts are Rosa indica L., Citrus aurantium L. and Syringa vulgaris L. In August 1974 a small quantity of C. pestis females were extractcr from a single soil sample from Tabriz, Azerbeidjan, Iran, using a centrifugal flotation method. The sample was taken from the root zone of a Populus nigra L. tree growing on a rather sandy soil on the Tabriz substation of the Iranian Plant Pests and Diseases Research Institute. In soil samples from approximately 400 other localities in Iran, which were examined for nematodes by the author, C. pestis was never observed. The specimens found in Iran agree morphologically with the descriptions given for this species. From the few published reports of this nematode, it is impossible to determine its original country of origin. The fact that the species is now considered to be polyphagous, suggests that it has not necessarily been disseminated with planting material of J. regia, which originates in the region between southeastern Europe and central Asia. (The author is grateful to Mr. M. Babadoost, Tabriz substation, and Mr. A. Hodjat Djalali, Tehran-Evin, both of the Plant Pests and Diseases Research Institute, for collection and processing of the soil sample).