A new entomopathogenic nematode Heterorhabditis atacamensis from Chile

An entomopathogenic nematode, Heterorhabditis atacamensis- Nematode Information New entomopathogenic nematode species was found in the soil collected from Atacama Desert in Chile and was named after Atacama Desert as Heterorhabditis atacamensis. I like the way nematode taxonomists (Edgington et al., 2011) used individual morphological characteristics to differentiate this new species from other morphologically similar species of entomopathogenic nematodes. For example, these researchers showed that the H. atacamensis differed from H. marelatus, H. downesi and H. amazonensis based on position of hemizonid (a nematode sensory organ), position of excretory pore and female tail terminus shape, and number and position of genital papillae, respectively.  Using molecular techniques, Edgington et al. (2011) were also able to distinguish H. atacamensis from closely related entomopathogenic nematode species, H. safricana.

 Research Paper

Edgington, S., Buddie, A. G., Moore, D., France, A., Merino, L. and Hunt, D. J. 2011. Heterorhabditis atacamensis n. sp (Nematoda: Heterorhabditidae), a new entomopathogenic nematode from the Atacama Desert, Chile. Journal of Helminthology 85: 381-394.

Influence of potting media on the virulence of entomopathogenic nematodes against black vine weevil, Otiorhynchus sulcatus

It has been demonstrated that five different types of commercial potting media including peat, bark, coir, and peat blended with 10% and 20% compost green waste can influence the virulence of entomopathogenic nematodes against third-instar black vine weevil, Otiorhynchus sulcatus.  For example, Heterorhabditis species including Heterorhabditis bacteriophora UWS1 strain, H. megidis, H. downesi can cause 100% mortality of black vine weevil grubs in all the five types of media but  Steinernema species including Steinernema feltiae, S. carpocapsae, and S. kraussei can cause 100% black vine weevil grub mortality only in the peat blended with 20% compost green waste.  These results suggest that when growers are selecting entomopathogenic nematodes to control black vine weevil, Otiorhynchus sulcatus in their nurseries/greenhouses, they should take into consideration the type of potting media used in growing their plants. Please read following paper for the information on the method of nematode application rates and timings.

Ansari, M. A. and Butt, T. M. 2011.  Effect of potting media on the efficacy and dispersal of entomopathogenic nematodes for the control of black vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae). Biological Control 58: 310-318.

Ansari, M.A., Shah, F.A. and Butt, T.M. 2010.  The entomopathogenic nematodeSteinernema kraussei and Metarhizium anisopliae work synergistically in controlling overwintering larvae of the black vine weevil, Otiorhynchus sulcatus, in strawberry growbags. Biocontrol Science and Technology. 20: 99-105.