Melon Weevil, Vol. 5, No. 15
Your Extension Experts
August 19, 2010
August 12, 2010
August 6, 2010
June 18, 2010
April 9, 2010
Ok, there is really no such creature as a melon weevil, but it is a bit of a wonder that there is not. With over 80,000 known species, weevils represent one of the largest families of living organisms on earth, the family Curculionidae. There are more species of weevils than all species of vertebrate animals combined. That’s all mammals, all birds, all reptiles, all amphibians, and all fish verses just one family of beetles.
Why are there so many weevils? Pick any plant and there are probably one or more species of weevils that feed on that plant. But weevils are specialists, with most species having a small host range. It’s this combination of diversity at the family level and host specificity at the species level that results in so many weevils.
The fake weevil in the corny photo exhibits one of the most distinguishing characteristics of adult weevils—that long slender snout*. This snout causes many people to mistakenly assume weevils have piercing-sucking mouthparts like stink bugs or mosquitoes. But weevils are beetles and all beetles have chewing mouthparts, and there is a pair of tiny mandibles at the end of the snout. Most female weevils use these mandibles to chew a hole into the fruit, seed or bark of the host plant and lay their eggs into these holes. When the larvae hatch, they are surrounded by food because they are inside some type of seed, fruit, or other nutrient rich plant material. This means weevil larvae do not have to travel to find food and explains why weevil larvae have no legs.
Following are a few examples of some species of real weevils we have in the Southeast and a brief description of how they feed. How many of these are you familiar with?
Boll Weevil: larvae feed in flower buds and bolls of cotton
Strawberry Weevil: larvae feed in flower buds of strawberries and blackberries.
Pecan Weevil: larvae feed inside pecan and hickory nuts
Acorn Weevils: many species; larvae feed inside acorns
Pales Weevil: larvae feed under bark of pine stumps and roots
Deodar Weevil: larvae feed under the bark of pine trees
Hunting Billbug: larvae feed on roots and crowns of turfgrasses
Maize Weevil: larvae feed inside dried kernels of corn, wheat and other grains
Cowpea Curculio: larvae feed inside ripening cowpea seeds
Plum Curculio: larvae feed inside peaches, plums and other fruits
Vegetable Weevil: larvae feed externally on leaves of brassica and other vegetables
Yellow Poplar Weevil: larvae feed as leaf miners in magnolia and yellow poplar leaves
*Recently, bark beetles, which includes species like southern pine beetles and Ips beetles have been placed in the family Curculionidae. Bark beetles do not have snouts, but their larvae are legless, and they share other common weevil characters. As the name suggests, the larvae of most bark beetles feed on the inner bark of trees.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
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