Tag: Elateridae

PRAIRIE GRAIN WIREWORM CAN TAKE A BITE OUT OF CROP YIELDS

This week’s instalment is a sneak peak at the soon-to-be published manual “Field Guide of Pest Wireworms in Canadian Prairie Crop Production,” written by Haley Catton, Wim van Herk, Julien Saguez, and Erl Svendsen! (stay tuned to this channel)

Wireworms are soil-dwelling insects that have challenged crop production on the Canadian Prairies since farming began in this region. They damage crops by feeding on seeds, roots or lower stems of almost all field crops, and are especially damaging to cereals. Since wireworms are often the only reason growers use insecticide-treated seed in cereals on the Prairies, understanding more about these pests can save costs and reduce unnecessary pesticide use.

Despite their common name and worm-like appearance, wireworms are not actually “worms.” Rather, they are the larval stage of a group of beetles called click beetles (Elateridae family). Their “clicking” is a defensive behaviour that when placed on their backs, projects them up to 30 centimetres (12 inches) or more into the air to escape danger and literally get them back on their legs

Selatosomus aeripennis destructor, or the Prairie grain wireworm, is the largest of Prairie pest wireworms, reaching up to 23 millimetres (1 inch). It is hard-bodied, segmented and yellowish in colour, with three pairs of legs. Adults are 8-13 mm long, black, hairless and have distinct hind angles.

More information about these pests (lifecycle, damage, control options, etc.) and others is available in the Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Management field guide. (en français : Guide d’identification des ravageurs des grandes cultures et des cultures fourragères et de leurs ennemis naturels et mesures de lutte applicables à l’Ouest canadien). Biological and monitoring information related to wireworms in field crops is posted by Manitoba Agriculture and Resource Development, and Alberta Agriculture and Forestry.

Prairie grain wireworm, larva. Photo: J. Saguez, CÉROM
Prairie grain wireworm, adult (click beetle). Photo: J. Saguez, CÉROM

Wireworms

Newly seeded fields should be scouted throughout the germination and emergence periods for a variety of insect pests – one of the most difficult to detect can be wireworms! Wireworms are the juvenile stages of a complex comprised of several species of Elateridae, commonly referred to as ‘Click beetles’. On the Canadian prairies, wireworm collections from field crops indicate that three economically important species of wireworms or click beetles can be present; Selatosomus destructor, Limonius californicus, and Hypnoides bicolor. According to van Herk and Vernon (2014), a wide variety of Elateridae have been described from across the Canadian prairies; Alberta 144 species described in Alberta, 108 species described from Saskatchewan, and 109 species described from Manitoba.

Review these two wireworm posts to learn more and supplement in-field scouting:

Wireworms – Insect of the Week (2018)

Wireworm distribution map – Weekly Update (2018)

Biological and monitoring information related to wireworms in field crops is posted by Manitoba Agriculture and Resource Development, and Alberta Agriculture and Forestry. Also, refer to the wireworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (2018; accessible in either English-enhanced or French-enhanced versions).