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Weevil on cactus - Cactophagus spinolae

Weevil on cactus - Cactophagus spinolae
Hereford, just W of Hwy 92, SE flank of Huachuca Mts., Cochise County, Arizona, USA
July 12, 2008
Oak-grassland interface, 5010' elev. Beetle is feeding on Opuntia (prickly pear).
I note that a number of weevils feed on cactus.

Moved from Cactus Weevil.

I agree with the species name, but what source suggests that the genus is Metamasius?

The correct genus is Cactophagus. This name was, for a time, dropped in favor of Metamasius, but was resurrected by Kuschel in this book: "Wibmer, G.J. & O'Brien, C.W. (1986) Annotated checklist of the weevils (Curculionidae sensu lato) of South America (Coleoptera: Curculionidae). Memoirs of the American Entomological Institute, 39, i-xvi, 1-563."

Cactophagus is also listed as a valid genus in "American Beetles" (vol. 2, Arnett, Thomas, Skelley and Frank).

Also, check this source: "Anderson, R. S., 2002. The Dryophthoridae of Costa Rica and Panama: Checklist with keys, new synonymy and descriptions of new species of Cactophagus, Mesocorylus, Metamasius and Rhodobaenus (Coleoptera; Curculionoidea). Zootaxa 80: 1–94."

The correct identification is:

Cactophagus spinolae validus

The sub-species validus occurs in the United States and also differes from the other sub-species (spinolae) in that it is entirely black.

what source suggests ... Metamasius?
Apparently, Drs. Art & Jim didn't get/read/believe the resurrection memo(ir)...

They treated the spp. as Metamasius spinolae validus

Arthur V. Evans, James N. Hogue. 2006. Field guide to beetles of California. California Natural History Guides, University of California Press, Berkeley. 334 pp. (1)

That's California for you....only one source and different than the world authorities on weevils. Please refer to the 3 sources I provided. One of those sources is "American Beetles". This site relies heavily on Arnett's "American Beetles" (which uses Cactophagus).

Also, I think scientific works trump "field guides".

That's California for you.... (?)
I don't want to get in a p*ss*ng match over this, but Dr. Evens is a contributing author to American Beetles and is asso. with the Smithsonian so I wouldn't write him off too quickly...

bio 1, bio 2.

However, I agree that BugGuide mostly does (and should) follow Am. Beetles so if anyone wants to move these two pix over, feel free to do so.

One final comment, I trust you'll agree that weevil taxonomy, in general, is not as settled as that of most other beetles, save some groups such as rove beetles.

I think you misunderstand my tone. It's quite simple. The correct ID is Cactophagus spinolae validus rather than Metamasius.

Moved from Scyphophorus.

Moved from Beetles.

Look at the genus Scyphophorus here I'd say it's definitely in the subfamily Dryophthorinae

Metamasius appears to be a better fit...
The Cactus weevil - Metamasius [formerly Cactophagus] spinolae validus - occurs in AZ and feeds on Opuntia. (1) Plate 288; pg 270.

Evens and Hogue (2006) list Agave and Yucca as the hosts of the two spp. of Scyphophorus, plus the femora of Bob's bug seems to be closer to that of Metamasius... Mike

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