Suitability of three trunk traps for capturing larvae of Lymantria dispar (L.) (Lepidoptera, Erebidae)

In this paper, we present the results of field investigations on the suitability of three types of trunk traps (‘Commercial 1’, ‘Commercial 2’, and ‘Prototype’) for capturing spongy moth (Lymantria dispar) larvae in two areas with different climates and forest ecosystems. In areas of NE Slovenia, which were characterized by Pannonian climate and regular rainfall during the research period (2022–2024), the ‘Commercial 2’ trap was the most suitable for the capture of old larvae. In a forest with 20–30 m tall trees with the dominant species Quercus robur, Carpinus betulus, and Pinus sylvestris, it proved easy to set ‘Commercial 2’ on trunks and change their parts upon inspection for captures. ‘Commercial 1’ traps proved to be less suitable, since their bags quickly were filled with water during downpours and consequently fell out of the traps. ‘Prototype’ traps proved to be the most suitable in an area with a Mediterranean climate (Greece), where the trees (Quercus spp.) were smaller (3–4 m) and both younger and older larvae could more easily come into contact with the sticky surface of the inner part of the trap, of which longer-lasting effectiveness was possible in a drier climate. For the mass trapping of larvae in urban areas with a more humid climate, we therefore suggest the use of ‘Commercial 2’ traps, and in areas with a drier climate, the use of ‘Prototype’ traps.