Evil Weevil – are weevils all bad?

Beetles, the hundreds of thousands of insects belonging to the Order Coleoptera, inhabit nearly every ecological niche on the planet. Approximately 350-400,000 beetles have been described since Carl Linnaeus began to re-classify life with binomial nomenclature in 1758. Weevils make up about 20% of the beetle order with over 60,000 known species making it the largest family in the animal kingdom. Yet, despite its impressive numbers man mostly knows it as a pest.

weevil snout
weevil snout

They get their pest reputation from the herbivorous members of the group, which make up about ½ of weevils. This type of weevil has mouthparts formed into a long protuberance, not for sucking as they might seem, but tiny chewing mouthparts at the end of their trademark snouts allowing them to pierce and dig into their food. The snout may also be used to make cavities for laying eggs in buds, seeds, stems, and roots of plants. As the larva and adults chew their way through their host they can cause much damage to the plant. Name almost any grain, fruit, or vegetable, and it is likely that at least one kind of weevil enjoys eating it. We are familiar with many of them devastating our crops and raiding our dried goods in our kitchen cabinets. This is where they get their bad reputation – but are Weevils truly evil? Perhaps there is still chance for the little beetles to redeem themselves.

mile a minute weed
Mile-a-minute weed invading

The invasive vine Persicaria perfoliata, also known as the “Mile-a-minute Weed”, aggressively spreads and chokes out native plants throughout the eastern U.S. Originally from Asia, it is speculated that the seed was spread to the United States with Rhododendron stock in the early 1900’s. Nothing could stop this weed until a weevil came to the rescue. Then, in 2004, the USDA approved the rearing and release of a Chinese weevil called Rhinoncomimus latipes, which was a specialist at consuming this meddlesome weed. In addition to eating the plant, weevils have demonstrated their lifestyles also delay seed production, stunt plants and cause mortality. Weevils that were grown in a lab were released into distressed areas for several years until the population was very well established. Some monitored sites throughout the areas of concern have shown a spring seed reduction within one to three years. So let us revisit our question are Weevils truly Evil?

Evil is typically associated with conscious and deliberate wrongdoing. While their wrong doings in our common perception might make them seem like quite the rebellious hellion, they are also qualified for good. With in the same undesirable aspects, in context, has been reversed into a desirable or positive quality suitable for helping us tame the damage we have done to our natural habitat. As with all insects, they are an invaluable member supporting our world’s natural ecosystems as pollinators, decomposers and protein rich food for animals, concluding that the only evil in a we”evil” in it’s name. Take a look at Weevil Knievel – he gives an impression of rebellion but is really a nice weevil when you meet him.

Megan Pearl/Kevin Clarke