PATHOGENICITY OF <i>Phasmarhabditis hermaphrodita, Heterorhabditis bacteriophora, Steinernema carpocapsae</i> and <i>Diplogaster</i> spp. AGAINST THE CLOVER LAND SNAIL, <i>Monacha cantiana</i>

GENENA M.A.M.¹, MOSTAFA F.A.M.^2
1Department of Agricultural Zoology, Faculty of Agriculture, Mansoura University, Mansoura, Egypt.
²Department of Agricultural Zoology, Faculty of Agriculture, Mansoura University, Mansoura, Egypt.

Received : 04-11-2013     Accepted : 03-12-2013     Published : 28-12-2013
Volume : 2     Issue : 1       Pages : 17 - 20
World Res J Agr Biotechnol 2.1 (2013):17-20

The pathogenicity of four nematode species namely, <i>Phasmarhabditis hermaphrodita, Diplogaster spp, Heterorhabditis bacteriophora</i> and <i>Steinernema carpocapsae</i> were tested at three inoculum levels i.e. 2000, 5000 and 7500 individuals against the clover land snail, <i>Monacha cantiana</i> after one, two and three weeks of exposure periods. Results indicated that all tested nematode species were found to be pathogenic to <i>M. cantiana</i> but in different proportions. A positive correlation has noticed between percentage mortality of tested snails and exposure time to tested nematode species and also within their inoculum levels. The rhabditid nematode, <i>P. hermaphrodita</i> was the most effective one against the clover land snail, <i>M. cantiana</i> in all inoculum levels followed by the diplogasteroid nematode, <i>Diplogaster</i> spp., then the entomopathogenic nematodes, <i>H. bacteriophora</i> and <i>S. carpocapsae</i> with mortality percentages amounted to 73.0, 30.0, 20.0 and 13.3%, respectively after three weeks of treatment. On the other hand, a comparative study on the two indigenous isolates of the rhabditid nematode, <i>P. hermaphrodita</i> against the clover land snail, <i>M. cantiana</i> under laboratory conditions indicated that Mansoura isolate (85.3%) reared <i>in vitro</i> exhibited the highest mortality percentage followed by Assiut isolate reared <i>in vitro</i> and <i>in vivo</i> with values of 72.3 and 66.6%, respectively, while Mansoura isolate (46.6%) reared on infested snails exhibited the lowest mortality percentage. Best results were obtained with the rhabditid nematode, <i>P. hermaphrodita,</i> rearing on <i>Pseudomonas fluorescens</i>.