A new species of entomopathogenic Steinernema nematodes / by Ganpati Jagdale

A new species of entomopathogenic Steinernema nematode that isolated from southwest Bohemia, Czech Republic was identified and named as Steinernema poinari sp. n. (Nematoda : Steinernematidae) using both morphological and molecular techniques (Mráček et al., 2014). This new species was recovered from soil using Galleria baiting technique described by Bedding and Akhurst (1975). Morphological identification of Steinernema poinari was based on morphometric measurements of its males, females and infective juveniles whereas its molecular identification was based on sequences of ITS and DNA regions of its ribosomal DNA. Based on molecular data, this new species was found to be closely associated with ‘affine/intermedium’ group of Steinernema spp. Based on the molecular characteristics (Genbank data) of previously reported Steinernema species and their close similarity with Steinernema poinari, these researchers suggested that this new species may be widely distributed in the Palearctic region (Mráček et al., 2014).  Infective juveniles of Steinernematid nematodes generally carry species specific symbiotic bacteria (Xenorhabdus spp.) in their gut and use them as weapons to kill their insect hosts. However, currently there is no information available on the association of specific symbiotic bacteria with Steinernema poinari. According to Mráček et al (2014), the area from which these nematodes were collected was mostly covered by naturally growing willow and alder bushes. This suggest that the different kinds of insect pests of both willow and alder buses may be serving as susceptible hosts for Steinernema poinari nematodes. Both willows (Salix spp.) and alder (Alnus spp.) are deciduous trees or shrubs that are grown for their colorful buds or catkins, stems, or contorted shape. Like other plants, these plants also have a wide range of insect pest that can reduce their aesthetic value. Two important insect pests of willow including Elm leaf beetle, Xanthogaleruca (=Pyrrhalta) luteola and the redhumped caterpillar, Schizura concinna can be good hosts of Steinernema poinari nematodes because their mature larvae generally moves in the soil for pupation. Infective juveniles of Steinernema poinari nematodes can easily find, infect and kill both the mature larvae and pupae of these insects and recycle themselves in the soil. The larvae of leaf flea beetles that cause dame to alder lease can be a susceptible host of Steinernema poinari nematodes.


Bedding, R.A. and R.J. Akhurst. 1975. A simple technique for detection of insect parasitic rhabditid nematodes in soil. Nematologica. 21: 109-110.

Mráček, Z., Půža, V. and  Jiří Nermuť, J. 2014 Steinernema poinari sp. n. (Nematoda: Steinernematidae) a new entomopathogenic nematode from the Czech Republic. Zootaxa 3:336-350.

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