Effects on Other Organisms

Pp. hermophrodita is considered as a lethal parasite for slugs, however, its affect on non-target organisms has not been extensively studied. Whatever, the information available makes the evidence clear that this nematode is safe for non-target snails, beneficial predators and earthworms. Under laboratory condition, the exposure of two snails, Cepaea hortensis and Monancha cantiana, to Pp. hermaphrodita showed susceptibility in snails, but no effect was found under field condition (Wilson et al. 2000). Morley and Morritt (2006) studied the effect of Pp. hermaph-rodita upon the two fresh water snails Lymnaea stagnalis and Physa fontialis at 'spray tank' concentration and a 50% diluted 'spray tank' concentration over a period of 14 days. A significant mortality in L. stagnalis was found at both application levels, however, Pp. fontialis was unaffected. When bioassay of Pp. hermaph-rodita was conducted against tenebrionid beetles Zophoba morio and Tenebrio molitor it was found that the nematodes do not infect either of the two organisms (Wilson et al. 1994). In another experiment under laboratory condition, adults of Pterostichus melanarius, the beneficial predatory carabid beetle was not killed when exposed at a high dose of Pp. hermaphrodita (Wilson et al. 1993d). The effect of a commercial formulation of Pp. hermaphrodita on the earthworm Eisenia fetida was tested. Adults of E. fetida were exposed in 1-l glass beakers to Pp. hermaphrodita at three different concentrations (1x, 10x and 50x of the field-recommended rate of 3 x 109 billion nematodes/hectare) during a 14-day period in an artificial soil substrate. Also in this experiment injured earthworms with posterior ends removed were exposed to the 10x field-recommended rate of the nematode formulation. The results showed that neither intact nor injured E. fetida was susceptible to the nema-todes during the 14 days of exposure even at a higher concentration, i.e. 10 and 50 times greater than the label dose (De-Nardo et al. 2004).

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