FEEDING A VOIDANCE OF TERRESTRIAL GASTROPODS TO CONSPECIFIC AND NONSPECIFIC MATERIAL

In laboratory tests the terrestrial gastropods Arion fasciatus,Deroceras reticulatum, Arianta arbustorum and Bradybaena fruticumpreferred control leaf discs over discs treated with an aqueoussuspension of crushed conspecifics. The response to suspensionsof different species was weaker. The strength of the responseincreased with the concentration of the suspension. The suspension'seffect in deterring feeding was inactivated within 18 to 32hours. Hunger reduced normal responsiveness to conspecific fluids;the quality of the control food also affected the response.The results also imply that ranking among individuals is labile.Spraying lettucc with the suspension affected the dispersalof the animals only in early summer. The article discusses thebiological significance of the response and the use of substancesobtained from slugs and snails in the control of pest gastropods. (Received 21 March 1991; accepted 5 September 1991)