Biological control of Myriophyllum aquaticum using the weevil Phytobius vestitus
Myriophyllum aquaticum (Haloragaceae: EPPO List of Invasive Alien Plants) is an invasive aquatic plant which is utilised as aquarium plant. It is invasive in the EPPO region and North America. Native to South America, M. aquaticum can reduce native biodiversity and have negative impacts on ecosystem services (e.g. reducing human activities in waterbodies, blocking irrigation channels). Traditional control methods, for example mechanical and chemical control, are either difficult to implement or not suitable for use in and around waterbodies. Biological control is one potential solution that is being explored for North America. The weevil Phytobius vestitus (Coleoptera: Curculionidae) was identified as a potential biological control agent for M. aquaticum. Experiments using olfactometer-based bioassays were conducted using eight closely related species in the family Haloragaceae, the target M. aquaticum, and seven non-target species. Choice (the weevil is presented with bioassays from more than one plant species) and no-choice tests (single plant bioassay) were conducted. The results show that P. vestitus was more attracted to the olfactory cues emitted by M. aquaticum compared to the other plant species. The results highlight that P. vestitus should be assessed further as a potential biological control agent for M. aquaticum.
Sources
Pessina A, Humair L, Naderi R, Röder G, Seehausen ML, Rasmann S, Weyl P (2024) Investigating the host finding behaviour of the weevil Phytobius vestitus for the biological control of the invasive aquatic weed Myriophyllum aquaticum. Biological Control 192, 105509. https://doi.org/10.1016/j.biocontrol.2024.105509