Weevil Scientific Name: Curculionoidea

Weevil Facts

There are over 60,000 types of weevils, which means it is likely you will come in contact with them at one time or another. Weevils are actually beetles from the Curculionoidea superfamily, and are sometimes found in cupboards, pantries or other places where grain, flour, or nut products are stored. They prefer a dry, cool area and are also likely to infest foods which have a long shelf life. Weevils are known for their destructive behavior and have a diet which consists of over 100 types of plant species; this makes them a garden pest if they’re left uncontrolled.

Weevils may cause damage to plants and can also infest food sources if left untreated. They can be a cumbersome pest in the garden but are not classified as a domestic pest. You can find weevils by looking underneath leaves in the springtime evening or by noticing signs of damage to plants. Weevils come in an assortment of bright colors but are remarkably small and hard to see. They are native to America and prefer dry, cool climates located in the northern states but inhabit most states.

Weevil Identification

Outdoor weevils are noted for their incessant chewing of leafs during the developmental stages. Grubs may produce a distinctive set of teeth marks which inflict the edges of leaves rather than the vein or flat portion, which is common to many other insects. You can also detect their presence in cupboards when noticing that flour sticks together, as though woven in a web. Adult weevils will be found underneath leaves or in mulch during the day.

Physical appearance depends on the weevil’s maturity. Adult weevils are distinguished by a hard, glossy shell and have six legs. They have a pair of antenna and are a remarkably small, long creature; weevils rarely extend to one full inch in length. Undeveloped weevils will take on the appearance of a grub, which is indifferent to many other developmental stages of insects. These chubby, worm-like creatures will feed regularly and will continue to develop into adults within as little as a few weeks.

Weevils Habitat

Weevils predominately live outdoors but may extend into the house seeking food and shelter. In this setting, they will seek out cupboards, pantires and other dry, cool storage spaces in kitchens, or less frequently, basements and attics. Outdoors, weevils are known to exist and eat from a wide range of plant life and will seek out cool, temperate climates that have a strong Eco-system, abundant vegetation, and little disruption. Adult weevils depend on bridging leaves to move between locations, as they cannot fly.

As with many insects, weevils are most active at night. During the day, weevils are likely to be found hiding under leafs or hidden in mulch that is placed at ground level. They only move up at night to feed. There are some plants; Blue Peter, Ruby Hart, and Creeping Jenny, which have been shown as preferential, but weevils will generally eat any plant.

Weevil Life Cycle

Weevils will emerge from their pupation cocoons in May or June of each year, and will begin to eat vigorously until they are prepared to lay their eggs. It is widely considered that weevils are strictly female, as no males have been found in America to date, but this also means they are hermaphrodites and are able to reproduce without the aid of a partner.

Damage to plants is caused by grubs, which is a developmental stage the weevils undergo before reaching maturity. The grubs require significant amounts of food in order to collect the required energy required for undergoing pupation. Weevils are rare in that they do not follow the usual mating or courtship rituals of their rival species.

The hatched weevils will appear during the following springtime, and will undergo a period of pupation before reaching sexual maturity. This period lasts for four to six weeks and will be followed by four to six weeks of feeding before the next generation of eggs are laid. The young will resemble their parent once mature. Eggs will hatch within two to three weeks and adults may expect to live between 100 to 200 days.

Weevils and Humans

Weevils may be a rare occurrence in the home. They can be removed and the area sanitized with ease. Weevils in the garden, however, can cause serious damage, especially in the early summer months when grubs are hungry and seeking food. They can become a problem if left untreated. Weevils are harmless to humans and are only one component of our Eco-system.

Weevil Control

Identification of the developmental stage can help determine which pest control method is most appropriate. In either case, sanitation can help prevent weevils from returning and will be required to remove any shredded skin, urine or fecal matter. Weevils are most active during the early evening, and control methods should be incorporated at this time for maximum effect.

Where adults are found:

Preventative measures: Ensure food items are stored securely, especially food items which are stored long term and used less frequently. Gardening can also help, as healthy plants have shown to be less attractive. You should reduce low-level branches and leaves to prevent easy access to the plant.

Green methods: Taking a damp that which has a small amount of dish soap and washing leaves can help remove weevils and prevent them from returning. This is also useful for the plant and should be carried out in the early evening for best effect.

Biological measures: Nematodes may be introduced to the soil as a biological control agent. These tiny worms prey on weevils and can help control population counts. This treatment is only valid in situations where soil temperatures remain bellow 55 degrees Fahrenheit.

Chemical measures: Chemical treatments may damage plant life and should only be considered once other measures have failed.

Where grubs are found:

The above methods may be of benefit, but it is worth noting that springtime preventative measures should be established to prevent weevils from returning. The sightings of grubs are an indication you are about to see many new weevils surface and that immediate action should be taken. Weevils can be managed in the home without professional assistance.

Weevils Entomology

Weevils belong to the animalia kingdom and are classed as insecta. They also belong to the arthropoda phylum, which is common to many other insects. Weevils is a common name for over 60,000 types of beetle; all of which belong to the Curculionoidea superfamily. They share the polyphaga suborder with other closely related insects but are specific to the Cucujiformia infra-order.