Olfactometric response of selected crop pests to the scent of common nettle (Urtica dioica L.) and the influence of aqueous plant extracts on their behavior

Abstract

The study examined the impact of aqueous extracts from Urtica dioica L. and fresh nettle parts on the feeding behavior of Sitona linea¬tus L., the survival of Aphis fabae Scop. on broad bean leaves, and the feeding of L4 larvae of Leptinotarsa decemlineata Say. Olfactory responses of the insects to nettle were also investigated. Results revealed that 10, 20 and 30% concentrations of aqueous extracts from fresh nettle significantly inhibited feeding in S. lineatus females. Conversely, the 10% extract from dried nettle had the most pronounced effect on S. lineatus males. Higher concentrations of common nettle extracts increased mortality in A. fabae females and larvae, with fresh extracts exhibiting a more potent impact. The body weight of L. decemlineata larvae slightly increased with all extracts, particularly the 30% concentration of fresh nettle. While all extracts reduced food consumption by L. decemlineata larvae, no discernible differences were observed based on concentration or preparation method. Olfactometer research indicated a repellent response of L. decemlineata females to common nettle odors, but no significant influence on the behavior of S. lineatus and winged A. fabae females was observed.