THE BREEDING SEASONS OF SLUGS IN GARDENS

Generalized life cycles of five slug species were ascertained from new data on weights of individual slugs together with information on the seasonal state of their genital organs in conjunction with Barnes & Weil's unpublished data on weights. Arion hortensis hatches mainly in January and February, grows through the summer months to become mature in September and October. These adults live through the winter, laying eggs and gradually losing weight and die before July of the following year. The eggs of Arion subfuscus are mainly laid in the autumn (late August and September) and hatch sporadically through the winter. The young slugs grow through the spring to become mature in July and the adults die soon after egg‐laying. Agriolimax reticulatus breeds throughout the year but the rate depends on the weather and each year there is a period of intense egg‐laying associated with the new spring vegetation, that results in a summer abundance of individuals. Milax budapestensis hatches during the autumn and winter, grows through the summer to become mature in late October and November when they mate and eggs are laid in the autumn and throughout the winter. The adults die before July of the following year. Milax sowerbii probably hatches in early spring, grows throughout the summer, becomes mature, mates and starts to lay eggs in September, October and November. The adults die soon after egg‐laying.