THE INFLUENCE OF FOOD DEPRIVATION ON THE LOCOMOTOR ACTIVITY OF SLUGS

Experimental animals used in studies of feeding behaviour areusually starved prior to observation, although little is knownof the behavioural effects of such pre-experimental treatment.This study investigated the effect of food deprivation on thelocomotor activity of two species of slugs, Deroceras reticulatumand Milax budapestensis. Locomotor activity was measured bythe quantitative assessment of mucus trails. The more surfaceactiveD. reticulatum showed a marked increase in its locomotoractivity when deprived of food, whereas the locomotor activityof M. budapestensis decreased. The implications of the resultsare discussed in relation to the ‘life-styles’ ofthe two species and the possible implications for the controlof slugs in the potato crop. ^*Present address: 59 Valley Park Drive, Clanfield, Hants. PO80PL. (Received 24 May 1986;     

LABORATORY STUDIES ON DAMAGE TO POTATO TUBERS BY SLUGS

The ability of eight species of slugs to damage intact potatotubers c .v. Maris Piper was investigated. Four species, previouslyimplicated as pests of field crops, caused primary damage totubers. Interactions between three of the species Milax budapestensis(Hazay), Arion hortensis (Fèrussac) and Deroceras reticulatum(Müller) were studied using potato tubers of five cultivars.Single species groups caused most damage to tubers and interactionbetween species reduced damage irrespective of cultivar. Theresults are discussed in relation to past work. ^*Present address: 59 Valley Park Drive, Clanfield, Hants. PO80PL. (Received 19 August 1986;     

THE INFLUENCE OF AN ALTERNATIVE FOOD ON THE EFFECTIVENESS OF PROPRIETARY MOLLUSCICIDAL PELLETS AGAINST TWO SPECIES OF SLUGS

The effectiveness of three types of molluscicidal pellets againstDeroceras reticulatum (Müller) and Arion hortensis (Férussac)was assessed in the presence and absence of potato leaf discs.Pellets containing methi-ocarb were significantly more effectiveagainst both of the slug species than either of the metaldehydeformulations, in the absence of leaf discs. When leaf discswere present, methiocarb was no more effective against D. reticulatumthan were the metaldehyde formulations. Leaf discs did not interferewith the effectiveness of methiocarb against A. hortensis. Theresults are discussed in relation to past work and more recentfield studies. (Received 24 March 1986;