Linogeraeus tonsilis (Boheman)

Prena, Jens, 2009, A Review of the Species of Geraeus Pascoe and Linogeraeus Casey Found in the Continental United States (Coleoptera: Curculionidae: Baridinae), The Coleopterists Bulletin 63 (2), pp. 123-172 : 164-165

Linogeraeus tonsilis (Boheman)

( Figs. 55, 56 , 63 , 79 )

Centrinus tonsilis Boheman 1844:218 . Type material in NHRS; not examined.

Centrinus (Odontocorynus) tonsilis ; Casey (1892).

Geraeus tonsilis ; Champion (1908).

Centrinaspis tonsilis ; Casey (1920).

Linogeraeus tonsilis ; Kuschel (1983).

Centrinaspis compar Casey 1920:407 . Holotype male, labeled ‘‘Mex’’ [encoded; stands for Cuernavaca], ‘‘Casey/ bequest/ 1925,’’ ‘‘Type USNM/ 37838,’’ Casey’s handwriting ‘‘compar/ Csy.’’ Synonymy by Kuschel (1983:39).

Centrinaspis logica Casey 1920:408 . Syntypes, 1 male, 2 females, labeled (1) ‘‘ Temax / N. Yucatan / Gaumer,’’ ‘‘σ,’’ ‘‘ Casey / bequest/ 1925,’’ ‘‘ Type USNM/ 37840 ,’’ Casey’s handwriting ‘‘logicus/ Csy’ ’; (2–3) ‘‘ Temax / N. Yucatan / Gaumer ,’’ ‘‘ Casey / bequest/ 1925,’’ ‘‘logica-2 [other specimen numbered 3]/ Paratype USNM/ 37840 .’’ Synonymy by Kuschel (1983:39).

Centrinaspis nugax Casey 1920:408 . Holotype female, labeled ‘‘ Mex,’’ ‘‘ Estado / Hidalgo,’’ ‘‘ Casey / bequest/ 1925,’’ ‘‘ Type USNM/ 37841 ,’’ Casey’s handwriting ‘‘nugax/ Csy.’’ Synonymy by Kuschel (1983:39).

Centrinaspis retracta Casey 1920:407 . Syntypes, 3 males, labeled (1) ‘‘Iguala/ Gro. Mex./ Wickham,’’ ‘‘Casey/ bequest/ 1925,’’ ‘‘Type USNM/ 37839 ,’’ Casey’s handwriting ‘‘retractus/ Csy’’; (2–3) ‘‘Iguala/ Gro. Mex./ Wickham,’’ ‘‘Casey/ bequest/ 1925,’’ ‘‘retracta-2 [other specimen numbered 3]/ Paratype USNM/ 37839 .’’ Synonymy by Kuschel (1983:39).

Centrinaspis scenica Casey 1920:407 . Holotype female, labeled ‘‘ Yzabal / Guatemala,’’ ‘‘ 100 ft,’’ ‘‘σ,’’ ‘‘ Casey / bequest/ 1925,’’ ‘‘ Type USNM/ 37837 ,’’ Casey’s handwriting ‘‘scenicus/ Csy.’’ Synonymy by Kuschel (1983:39).

Centrinaspis sparsella Casey 1920:400 . Holotype female, labeled ‘‘ Chilpancingo / Guerrero./ Hoege.,’’ Champion’s handwriting ‘‘ Geraeus / tonsilis/ Boh ,’’ ‘‘ Casey / bequest/ 1925,’’ ‘‘ Type USNM/ 37842 ,’’ Casey’s handwriting ‘‘sparsellus/ Csy.’’ Synonymy by Kuschel (1983:39).

Recognition. In the United States, L. tonsilis has a rather dense, uniform grayish vestiture and can be confused especially with L. finitimus and L. neglectus . Male L. tonsilis can be identified easily by the lack of prosternal spines, which are present in the other two species. Most female L. tonsilis can be identified by the shapes of the rostrum, pronotum, and body, as described in the key. Stout specimens, which are particularly common in northern Mexico and the United States, require careful comparison with identified material. Specimens from central Mexico tend to be larger and more slender, the body of the aedeagus is longer, and the vestiture typically consists of more elongate yellowish scales.

Distribution. The species occurs from the southern United States south to Costa Rica ( Fig. 79 ).

Type locality. Mexico .

Material examined. United States: Arizona ( CWOB 4 , JPPC 2 , USNM 5 ), Kansas ( USNM 1 ) , Nebraska ( UNSM 3 ) , New Mexico ( CWOB 2 , TAMU 2 , USNM 9 ), Oklahoma ( CWOB 1 , TAMU 1 ), Texas ( CMNC 2 , CWOB 92 , TAMU 20 , USNM 2 ) . Costa Rica ( USNM 1 ) , El Salvador ( TAMU 3 , USNM 7 ) , Honduras ( CWOB 1 , TAMU 15 , USNM 1 ) , Mexico ( CWOB 68 , TAMU 50 , USNM 72 ) , Nicaragua ( TAMU 1 ) . Total 363 specimens .

Temporal occurrence. June to September.

Plant associations. Poaceae : Z. mays (Harrison and Fraser, reared from stalk; several collectors, observations; interceptions from Mexico, Guatemala, and Honduras).

Note. Linogeraeus tonsilis is newly recorded for the United States. The first specimens were collected close to the Mexican border, in New Mexico 1908 and in southwest Texas 1914. In the 1940s, the species had already reached Kansas and Nebraska, and expert opinion was requested for the first time. USDA weevil specialist Lee Buchanan identified these weevils in 1947 as Centrinaspis nugax Casey , now considered a synonym of L. tonsilis . However, further specimens submitted during the 1960s were not identified to species. The progressing range expansion combined with the continued interceptions at ports of entry in New Mexico and Texas leave little doubt that L. tonsilis is an adventive species in the United States.

Figures

Figs. 49–56. Linogeraeus species, dorsal and lateral aspects; scale bar 1 mm. 49, 50) L. finitimus, male; 51, 52) L. neglectus, male; 53, 54) L. squamirostris, female (dorsal), male (lateral); 55, 56) L. tonsilis, female, New Mexico, U.S.A.

Figs. 61–70. Geraeus and Linogeraeus species; 61–63, aedeagus, dorsal aspect of apical portion; 64–67, rostrum, dorsal aspect; 68–70, antenna. 61) L. finitimus; 62) L. neglectus; 63) L. tonsilis; 64) L. finitimus, male; 65) L. finitimus, female; 66) L. neglectus, male; 67) L. neglectus, female; 68) G. picumnus, female; 69) G. timidus, female; 70) L. capillatus, female.

Figs. 78–79. Map of United States (without northwestern part) and Central America showing distributions of L. hospes, L. laevirostris, L. perscitus, L. tonsilis, and L. squamirostris.