10 August 2022
Mmulti-species lure proves itself in development work.
Agriotes beetles are one of the most economically damaging pests of arable and horticultural crops. Their slow-growing larvae (wire worms) feed on the roots of a potatoes, making them unfit for human consumption. Plant damage includes boring and feeding of roots and injury to stem bases, patchy seedling emergence and wilting of seedlings.
Three most common pest species are Agriotes lineatus (lined click beetle), Agriotes obscurus (dusky wireworm) and Agriotes sputator (common click beetle). Globally, the lined click beetle is the most common pest and is found throughout Europe, Northern Asia, North America and New Zealand. The harmful larval stage can extend from three to five years.
Because the larvae are difficult to control by conventional methods such as ploughing, the industry primarily relies upon insecticides to manage this pest. Pheromone traps are often used to monitor individual Agriotes species and growing interest in this pest has resulted in Agriotes lineatus becoming one of the most studied of all beetles.
Although pheromones have been identified for all three species and pheromone lures are commercially available for each species, until now a single lure for all three species has not been available.
Scientists at International Pheromone Systems (IPS) decided that an effective lure that attracts all three commonly encountered species would be advantageous to growers so that control strategies can be rapidly implemented if trapped numbers of either species are high in monitoring traps, It has now developed a new lure that can help farmers to monitor all three types of Agriotes beetles.
Previous traps available for monitoring were expensive and overly complex to put together and install. IPS has recently developed a new pitfall type trap for weevil pests and this design was thought to be suitable for monitoring of Agriotes beetles.
Development work was undertaken over the Spring of 2022 to assess the new trap design and three lure types: a standard single species lure; a multi-species lure using the standard polyvial dispenser format and a multi-species lure using a new dispenser design.
The new dispenser design containing a multi-species formulation significantly outperformed the other two lures and attracted all three pest species. The majority of the beetles caught were the commonest species, Agriotes lineatus but good numbers of Agriotes obscurus were also trapped in addition to small numbers of Agriotes sputator.
Technical Manager for IPS Dr Sam Jones said: “This is really good news for growers who have to battle with this very common and damaging pest species. Often when pheromone formulations are developed to attract multiple species we see a loss in efficacy when compared to a single species variant. However, this was not the case for Agriotes lineatus in this trial which showed that the IPS multi-species lure variant can be used with confidence. The IPS trap was found to perform as well other traps in the field and offers a more robust option for growers. Attraction maybe further improved by using a second lure within the bucket and this will be researched in 2023.”
The comparative trial was carried out on land used to grow a variety of root and vegetable crops for Jones Farm Shop, located close to Ellesmere Port in Cheshire, England.