Laboratory evaluation of potential molluscicides for the control of eggs of the pest slug Deroceras reticulatum (Muller) (Pulmonata: Limacidae)

Laboratory experiments were done to test the efficacy of a number of pesticides against the eggs of the field slug, Deroceras reticulatum (Muller). Research was based on paper-contact toxicity tests in which the eggs were continuously exposed to the compounds and the mortality rate assessed each day. The compounds tested included molluscicides (metaldehyde and methiocarb), herbicides (ioxynil, bromoxynil, pyridate), insecticides (thiocyclam hydrogen oxalate, imidacloprid, diflubenzuron, teflubenzuron, azadirachtin), and other compounds such as saponin, carvone and Pongamia pinnata (L.) extract. The herbicides ionynil and bromoxinyl, and the active ingredient of neem (Azadirachta indica A. Juss) oil, azadirachtin, killed all the eggs of D. reticulatum at doses <0.05 mg cm(-2) after 24-h exposure.