Weevils

A Costa Rican weevil Cholus cinctus in flight. [Canon 1D MkII, Canon 16-35mm, 2 speedlights Canon 580EX]

A Costa Rican weevil Cholus cinctus in flight. [Canon 1D MkII, Canon 16-35mm, 2 speedlights Canon 580EX]

J. B. S. Haldane, the British geneticist, is often quoted for proclaiming, “The Creator, if He exists, has a special preference for beetles.” (*) With between 275,000 to 350,000 described species of beetles it is hard to argue with this statement. Of these, about 60,000 species belong to a single family, the weevils (Curculionidae), making it not only the largest among beetles, but also of all living organisms. Their evolutionary success may be based in the morphology of their mouthparts, which in most species are situated at the tip of a long rostrum or snout. This allows such species to bore deep holes in even the hardest seeds or nuts in order to deposit their eggs there, providing developing larvae with a safe environment and a rich supply of food. It is also certain that the weevils’ success is related to the diversification of flowering plants, which began in the Cretaceous. A process known as coevolution, which can be compared to an arms race between plant-feeding beetles and their hosts, has led to a steadily increasing specialization of beetle species in response to the evolution of better defensive strategies of plants, and an almost exponential increase of their numbers.

[An excerpt from my book "The Smaller Majority."]

(*) The exact wording of Haldane’s famous phrase has never been confirmed, but only this sentence appeared in print in a summary of his speech given to the British Interplanetary Society in 1951; the wording that includes the phrase “inordinate fondness of beetles” is probably apocryphal.

The bearded weevil (Rhinostomus barbirostris) is a species with an interesting sexual polymorphism. A proportion of males in each population is smaller than other individuals of this sex, and resembles females in their appearance. This allows them to sneak unnoticed past the larger males and approach the female without being challenged (Costa Rica). [Canon 1Ds MkII, Canon 180mm macro]

The bearded weevil (Rhinostomus barbirostris) is a species with an interesting sexual polymorphism. A proportion of males in each population is smaller than other individuals of this sex, and resembles females in their appearance. This allows them to sneak unnoticed past the larger males and approach the female without being challenged (Costa Rica). [Canon 1Ds MkII, Canon 180mm macro]

The long “neck” of the giraffe weevil (Trachelophorus giraffe) is used in ritualized male combat (Madagascar). [Nikon D1X, Sigma 180mm macro]

The long “neck” of the giraffe weevil (Trachelophorus giraffe) is used in ritualized male combat (Madagascar). [Nikon D1X, Sigma 180mm macro]

2 thoughts on “Weevils

  1. I suspect now the staphylinid people might argue theirs is the largest family…regardless weevils are fascinating. Great photos as usual!

  2. Pingback: Links 12/18/12 | Mike the Mad Biologist

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