Wireworms, the larval stage of click beetles, are common soil inhabitants found in gardens and agricultural fields. These slender, hard-bodied larvae range from 1/4 to 1 1/4 inches in length and exhibit a yellowish-brown, segmented appearance. They spend several years underground, feeding on plant material before transforming into adult click beetles. This article clarifies the impact of wireworms on human health and their role as agricultural concerns.
Do Wireworms Pose a Threat to Human Health?
Wireworms are not considered harmful to humans or pets. They do not possess mouthparts capable of biting or stinging people, nor do they transmit diseases to humans or animals. Their interaction is primarily with plants, specifically their underground parts. Wireworms do not transmit diseases to humans through contaminated soil or food. Direct contact with wireworms does not pose a health risk.
Wireworms as Agricultural Pests
While not directly harmful to humans, wireworms are significant pests in agriculture and home gardens. They cause damage by feeding on seeds, roots, tubers, and underground stems of various crops. This feeding can lead to stunted plant growth, wilting, or the death of young seedlings, resulting in reduced plant stands.
Wireworms affect a wide range of crops, including corn, potatoes, carrots, sugar beets, beans, grains, and lettuce. In crops like potatoes, wireworms tunnel into the tubers, which can render them unmarketable. Crop losses due to wireworm damage in North America can range from 5% to 25%, highlighting their economic impact on agricultural production.
How to Manage Wireworm Infestations
Managing wireworm infestations involves a combination of strategies to reduce their populations and protect crops. Crop rotation is an effective cultural practice, as certain crops can reduce wireworm numbers or deter them. For instance, including alfalfa or mustards in rotation can help decrease wireworm populations. Conversely, planting susceptible crops immediately after grasses or pasture can increase infestation risk.
Soil management practices also play a role in control. Intensive plowing or tillage can expose wireworm larvae to predators, heat, and desiccation, reducing their survival. Good soil drainage and removing plant debris can also make the environment less favorable for wireworms. Controlled soil drying or flooding can reduce populations.
Biological control methods include the application of beneficial nematodes. These microscopic roundworms infect and kill wireworms in the soil, offering an environmentally sound control option. Chemical treatments, primarily seed treatments, are available for agricultural use to protect germinating seeds and young seedlings. These treatments are preventive and require application prior to planting, as rescue treatments are not effective once damage is observed.