Insecticidal activity of Ageratina adenophora (Asteraceae) extract against Limax maximus (Mollusca, Limacidae) at different development stages and its chemical constituent analysis

Abstract

Abstract The great grey slug, Limax maximus is one of the common agricultural pests, which infesting the growing period of vegetables by making holes or lacerations in the leaves of vegetables, especially seedlings and tender leaves. To evaluate the insecticidal activity of Ageratina adenophora extract against slugs, the fecundity, growth, hatching rate, offspring survival rate, protective enzyme and detoxifying enzyme activity of slugs in different periods exposed to LC50 of the extract for two different time intervals (i.e., 24 h, 48 h), and extracts phytochemical variability were studied. The LC50 values of the A. adenophora extract against L. maximus was 35.9 mg/ml. This extract significantly reduced the hatching rate of eggs and the survival rate of offspring hatched from exposed eggs compared to the control, which exposed for 48 hours was lowest. The survival, growth, protective enzyme and detoxification enzyme activity of newly hatched and 40-day-old slugs decreased. In the A. adenophora extracts, tannins, flavonoids and saponins were identified, which may be beneficial in their biological effects. These results suggest that A. adenophora extract can be used as an alternative drug to kill slugs to effectively control the species.