Texas Beetle Information

Return to Texas Entomology - Compiled by Mike Quinn


Giant Palmetto Weevil

Rhynchophorus cruentatus (Fabricius 1775)

Family Curculionidae, Subfamily Dryophthorinae, Tribe Rhynchophorina


The largest weevil in North America

Palmetto Weevil - Rhynchophorus cruentatus (Fabricius 1775)

(male - at bait)

World Birding Center HQ
Bentsen-Rio Grande Valley State Park
Mission, Hidalgo County, Texas
April 24, 2008 (Joshua S. Rose)

Josh reported an additional record, same location, Nov. 3, 2008.


Range: Native to Florida.

Texas:

McAllen, being the City of Palms, likes to plant everything that looks like a palm. Much palm nursery stock comes from or passes through Florida. Larry Pressler, Director of McAllen's Parks and Recreation Department, reported (pers. comm. Apr. 2008) periodically finding the weevil in McAllen since ca. 1983.

Brownsville area - Tong-Xian Liu, Professor of Entomology, Texas A&M System, Weslaco reported (pers. comm., Apr. 2008) a palm nursery in Brownsville ca. 2005 having weevil infested stock that came from the Miami area.

Mission area - Joshua S. Rose, Ph.D. reported a Palmetto Weevil coming into bait at Bentsen-Rio Grande Valley State Park on April 24, 2008.

Despite EXTENSIVE beetle surveys of the Sabal Palm Audubon Center (south of Brownsville) and surrounding regions, there are only two Texas records in the TAMU Insect Collection:

1-TX: Galveston Co. Galveston, III-2004, Coll. W. Johnson. 
1-TX: Bexar Co., San Antonio, near Sea World, V-2000, N. Riggs, 
            "found crawling in parking lot, may have been assoc. with introduced Sabal palms"

Staff contacted April 2008 at both Sabal Palm Audubon Center and Lennox Foundation Southmost Preserve report no records of the Palmetto Weevil from their palm forests.

Hosts

It's natural host is the Cabbage Palmetto - Sabal palmetto, a palm native to the southeastern U.S.
However, adults and larvae associated with a WIDE variety of genera and species in the palm family Arecaceae.
It is NOT known to be a pest of the Texas Sabal Palm Tree - Sabal mexicana.

Significant pest on the following non-native palms:

Chinese windmill palm - Trachycarpus fortunei - (Larry Pressler, pers comm, Apr 2008)
Canary Island date palm - Phoenix canariensis - (Hunsberger, et al. 2000).

Flight Period: 

These active fliers and can be found throughout the year in Florida. However, adult activity is usually more noticeable in the late spring and early summer months.

Biology

Larvae feed in the crown of the palm. If infestation is severe, the the integrity of the crown is compromised and the top of the palm falls over. The entire life cycle, from egg to adult, takes about 84 days. Adults may live for several weeks (up to 26 weeks in captivity).

Similar Species: 

Rhynchophorus palmarum (Linnaeus 1758) - South American Palm Weevil - photo - found in California

Weblink: palmetto weevil - Featured Creatures - University of Florida

Photos: Adult Palmetto Weevils vary in color from solid black to almost completely red with a variable black pattern.

adult - series showing size and color variation

Note: Larvae of palm weevils are considered "culinary delights", see: The Impressive Rhynchophorus

EtymologyRhynchophorus cruentatus (Fabricius 1775)

rhynch, -o, =us (G). A snout, beak
phor, -a, -e, -i, -o (G). Carry, bear
cruent (L). Bleeding, bloody

Biography: Johan Christian Fabricius (1745-1808) - Wikipedia


References:

Arnett, R.H., Jr., M.C. Thomas, P. E. Skelley & J.H. Frank. (editors). 2002. American Beetles, Volume II: Polyphaga: Scarabaeoidea through Curculionoidea. CRC Press. 861 pp.

Borror, D.J. 1960. Dictionary of Word Roots and Combining Forms. National Press Books, Palo Alto. v + 134 pp.

Hunsberger, A., R.M. Giblin-Davis, & T.J. Weissling. 2000. Symptoms and population dynamics of Rhynchophorus cruentatus (Coleoptera: Curculionidae) infestation in Canary Island date palms. Florida Entomologist, 83(3): 290-303.

Wattanapongsiri, A. 1966. A revision of the genera Rhynchophorus and Dynamis (Coleoptera: Curculionidae). Department of Agriculture Science Bulletin, Bangkok, Thailand. 1, 328 pp.


03 Nov 2008   Mike Quinn / mike.quinn@tpwd.state.tx.us / Texas Entomology / Texas Beetle Information