Report of nine species of criconematide nematodes from forests of the Mazandaran Province, Iran

The Mazandaran Province occupies more than half of the area of Hyrcanian forests in the north of Iran and has a very diverse vegetation.In order to be aware of the entry of important plant parasite nematodes into these forests and to prevent their spread to downstream farms and gardens, continuous monitoring and determination of the density of important plant parasite nematodes in this area was necessary.Ninety rhizosphere samples of forest trees, including maple, birch, oak, raspberry, alder, walnut, and hornbeam, were collected from this province in 2020.Nematodes were extracted from the samples by wet sieving and centrifugation method, and after fixing, permanent slides were prepared from them and their morphological indices were measured and identified using valid keys.Also their frequency in the samples and their population density in 200 cm 3 rhizosphere were determined.Nine nematode species from the superfamily Criconematoidea were identified from the rhizosphere of these trees under the following names: Criconemoides informis, Criconemoides parvus, Mesocriconema solivagum, Mesocriconema xenoplax, Crossonema civellae, Crossonema menzeli, Ogma fagini, Xenocriconemella macrodora, and Paratylenchus straeleni.Among these nematodes, C. parvus had the highest frequency, and population density in the rhizosphere of alder trees in the Dohaz forest of this province.Some of these plant parasitic nematodes in high populations, in addition to direct damage to the roots, cause the spread of some plant diseases and exacerbate the effects of frostbite.