Monday, 4 June 2018

Insect of the Week (June 4, 2018) - Wireworms

This week's Insect of the Week is a frustrating pest of many crops: wireworm. Wireworms are the soil-dwelling larval stage of the click beetles (Elateridae). There are hundreds of click beetle species in the prairies, but the term wireworm refers to those that are pests, which in Canada is approximately 20 species.  With the loss of effective insecticides (e.g. lindane), wireworms have re-emerged in recent years as primary pests of potato, cereals, and vegetables. On the prairies, we have 3 predominant pest species (Selatosomus destructor, Limonius californicus, and Hypnoidus bicolor; see photo), and their larvae vary (among other things) in life history (2-7 years), color (white to orange), cuticle thickness, distribution, behaviour, and susceptibility to insecticides.

Wireworms are patchy in distribution, difficult to monitor, and difficult to kill. We have a lot to learn about these resilient pests. Since the mid-1990’s AAFC has had a national research team (Bob Vernon et al.) screening for effective insecticides and developing trapping and monitoring methods, cultural controls (e.g., crop rotation), and biocontrols to manage the adult and larval forms of these pests.

For more information about wireworms, check out our Insect of the Week page!
The three most troublesome wireworm species on the prairies in their adult
and larval stages. Note the different sizes and colours. From left to right,
S. destructor, L. californicus, H. bicolor.
Photo by David Shack, AAFC-Lethbridge.
For more information, please contact Dr. Haley Catton (AAFC-Lethbridge) or Dr. Wim van Herk (AAFC-Agassiz)

Also link here to access a summary of Wireworm surveying (2004-2017) conducted across the Canadian prairies by van Herk and Vernon (AAFC-Agassiz).