Driftless Prairies: Native Habitat Restoration

Nature inspires awe!

Curculionidae (Snout & Bark Beetles)

This is the biggest family of living beings!! North America has 3,100 species and the world has 60,000 weevil species – that’s more than any other invertebrate! Although they sport long, pointed-appearing snouts, weevils are chewing insects. They have a distinctive beak that allows them to bore into the protective shells of nut, fruits, and bark so they can feed on the soft insides. Females will use these same holes to insert their eggs into the plant tissue. The larval feeding cause the fruit to drop allowing the pupa to mature in the soil. Adults overwinter in the soil.

While there are weevil pests, the majority of weevils are beneficial, attacking dandelions, thistles, purple loosestrife, and other unwanted non-native plants.

This is a large family with many species, their life histories, morphologies, and behaviors are fairly variable. However, none have palpi or a labrum (otherwise present in nearly all beetles); none are predators, none are detritivores, none are fungivores (at least, not as larvae), none are parasites on other animals, none are free-swimming (though some are amphibious), and all larvae are non-ambulatory (they develop inside their food source). With those restrictions, almost anything else goes, and essentially any living or dead plant or plant part is fair game. They are the most successful and diverse group of obligate herbivores on earth, and you have to go pretty far out on their family tree before anything related to them is not an herbivore or fungivore, so, really, the lineage they belong to is well over 110,000 plant feeding species. That’s why they’re considered pests. Species-wise, most do not have long snouts; those with long slender snouts generally drill into seeds or hard fruits. –Doug Yanega

Certain species of potter wasps (Eumenes spp) will prey on this family of beetle larvae. Another tiny and rare wasp group in the Vespidae family hunts weevil larvae as well. For those weevils that are considered pests in the garden, these tiny wasps are big heros!