TRANSPORT OF UNCONTAMINATED AND MOLLUSCICIDE-CONTAINING FOOD IN THE DIGESTIVE TRACT OF THE SLUG DEROCERAS RETICULATUM (MULLER)

By X-ray analysis of food transport in the alimentary tractof Deroceras reticulatum it was shown that even ten hours afteringestion of a thorium sulfate-containing bait, this materialcan be detected in the crop. After 2.5 h, some parts of labelledfood passes down from the anterior to the posterior part ofthe gut. After 13 h, thorium sulfate-containing material canbe observed only in the gut. After 19 h, no more labelled materialis present in the alimentary tract of the animals. After addition of Cloethocarb, the animals feed on only smallamounts of food. The labelled material only enters the anteriorpart of the gut. After ten hours, the food does not move anymore and does not leave the crop even 19 h after feeding. After molluscicide application, the crop epithelium is moreinfolded than in control animals and the cells are elongated.After 30 h, cells protrude into the lumen of the digestive tract. (Received 11 May 1992; accepted 26 June 1992)     

EFFECTS OF ORALLY AND DERMALLY APPLIED METALDEHYDE ON MUCUS CELLS OF SLUGS (DEROCERAS RETICULATUM) DEPENDING ON TEMPERATURE AND DURATION OF EXPOSURE

Using light and electron microscopy in combination with histochemicaland immunocytochemical techniques, the impact of orally anddermally applied metaldehyde on mucus cells in the digestivetract, the skin, and the salivary gland of the slug Derocerasreticulatum (Müller) was investigated. The studies showedthat metaldehyde induces severe alterations and damages in mycocyteseven under low temperature and humid conditions when sufficientlyhigh doses were applied. After metaldehyde application, notonly the quantity of mucus produced by slugs but also its qualityis modified. Structural, enzymehistochemical and immunocytochemicalinvestigations revealed metaldehyde-induced effects in mucocytesto be related to influences of the molluscicide on serotoninand on energy metabolism. (Received 29 September 1997; accepted 8 December 1997)