Friends of Allestree Park

Allestree Park in Derby, England

The Acorn Weevil in Allestree Park by Bill Grange

Weevils are the largest class of beetles in terms of number of species - the characteristic feature being a snout or rostrum on the head which bears the antenna and jaws at the tip.

The Acorn Weevil occurs quite commonly in Allestree Park. They are about 1cm long and have snouts with small, saw- like teeth. With their large eyes and long snouts, they can possibly be called 'cute'! however, the downside is that they can reduce the capacity of oaks to reproduce by damaging their acorns.

Adults feed on the acorns, chewing or or drilling into the shells to feed on the tissue inside. They generally feed on acorns still attached to oak trees. After eating their fill, females often lay eggs in the acorns on which they've fed. They lay their eggs in the holes drilled into acorns during feeding. The pictures here show the weevils boring through the cup of the acorn - which would offer more purchase.

Legless larvae hatch a few days after laying. There may be one to several acorn weevil larvae in each acorn. Larvae typically go through five growth stages, or instars. Each instar ends with moulting or shedding of the old skin. After a few weeks the larvae chew their way out of the acorn and burrow into the soil to pupate, eventually emerging as adults after one or more years.


acorn weevil comp

Acorn Weevil, Curculio glandium

Two different females: The one on the left is burrowing into the cup of an acorn, using its long 'snout', correctly called a rostrum. On the right, a different female is laying an egg in the burrow she has just made. Photos taken in Allestree Park by Bill Grange and Steve Plant,  September 2012.

Sept. 2012

Friday, January 18, 2019