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Acorn Weevil (Conotrachelus posticatus)

Detailing the identifying qualities of the Acorn Weevil, including physical features and territorial reach.

 Updated: 1/30/2018; Authored By Staff Writer; Content ¬©

  Acorn Weevil  
Picture of Acorn-Weevil

The nut-loving Acorn Weevil efficiently uses acorns that it collects: as larvae, acorns are food, and as adults, acorns are a secret nursery.

Acorn Weevils have a long snout reminiscent of an elephant's trunk. This unique proboscis makes it easier to identify this type of beetle. This snout has chewing mouth parts at the end. Females lay a fertilized egg into the soft tissue of a young acorn, the seed of oak trees, when they first start growing.

Through summertime, the acorn grows and hardens. Inside the weevil larva feeds on the seed's interior. In early autumn, the acorn falls off the branch onto the ground below. Soon after, the weevil larva (now a curvy, legless grub) chews a small hole into the acorn seed and leaves the acorn in early winter, burrowing into the soil. There it can remain hidden from predators while it develops into an adult. The larvae are a protein-packed food source for many other insects, as well as spiders and small animals.

Acorn Weevils can inhibit oak tree expansion if an area is infested. Their larval diet of acorns can result in fewer new oak trees in that area, however, existing trees are not in any danger. Adult Acorn Weevils are hunted by a variety of Weevil Wasps and can eventually become living meals for hatching wasp larvae.

Acorn Weevil Information

Category: Beetle
Common Name: Acorn Weevil
Scientific Name: Conotrachelus posticatus
Other Name(s): Nut Weevil

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Coleoptera
     Arrow graphic Family: Curculionidae
      Arrow graphic Genus: Conotrachelus
       Arrow graphic Species: posticatus

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 4 mm to 10 mm (0.156 inches to 0.39 inches)
Identifying Colors: brown, black
Additional Descriptors: snout, trunk, nose, hairy, fuzzy, flying

North American Territorial Reach (Though Not Limited To): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan; Mexico

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

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