Sennius abbreviatus (Say, 1824)

Viana, Jéssica Herzog & Ribeiro-Costa, Cibele Stramare, 2013, Review of the largest species group of the New World seed beetle genus Sennius Bridwell (Coleoptera: Chrysomelidae), with host plant associations, Zootaxa 3736 (5), pp. 501-535 : 507-509

Sennius abbreviatus (Say, 1824)

( Figs 1–8 )

Curculio abbreviatus Melsheimer, 1806: 30 (catalog name).

Bruchus abbreviatus Say, 1824: 308 (description); Dohrn 1879: 187 (citation); Pic 1913: 19 (catalog).

Sennius abbreviatus: Bottimer 1968: 1025 (taxonomy, distribution); Johnson 1969: 55 (list); Johnson & Kingsolver 1973: 17 (description, key, figures, type designation, taxonomy, host); Johnson & Kingsolver 1981: 419 (catalog, distribution); Udayagiri & Wadhi 1989: 99 (catalog); Baskin & Baskin 1977: 61 (biology); Kingsolver 2004: 200 (key, diagnosis, figures, host, distribution); Johnson & Romero 2004: 404 (biology).

Bruchus bivulneratus Horn, 1873: 325 (description, key, distribution); Dohrn 1879: 187 (citation); Riley & Howard 1892: 494 (biology, host); Schaeffer 1907: 293 (distribution); Blatchley 1910: 1237 (catalog); Fall 1910: 165 (key); Cushman 1911: 494 (biology, host); Pic 1913: 19 (catalog); Zacher 1952: 461 (catalog); Bottimer 1968: 1025 (synonym).

Mylabris bivulneratus: Leng 1920: 305 (catalog).

Sennius bivulneratus: Bradley 1947: 39 ; Blackwelder & Blackwelder 1948: 45 (catalog); De Luca 1965: 68 (catalog); Johnson 1968: 1270 (type designation); Schoonhoven 1976: 692 (distribution).

Redescription. Dimension. BL: 2.1–3.0 mm; BW: 1.5–2.1 mm.

Integument color. Head black with maxillary and labial palpi dark brown; antennomeres 1–4 red-orange to reddish brown, 5–11 red-orange to brown ( Figs 2, 3 ). Elytra black, each with rounded red-orange macula covering most of anterior region from 2nd or 3rd interstices to behind humerus. Remaining thorax black ( Figs 1, 2, 4 ). Foreleg pale to dark brown. Mid femur usually dark brown to black. Mid and hind tibiae pale brown to black. Hind femur dark brown to black, sometimes with small area of lighter color. Tarsus red-orange ( Fig. 2 ).

Pubescence. Head with small white dense setal patch posterior to post-ocular lobe, remainder of head with sparse white setae; labrum with scattered golden setae, denser at apex ( Fig. 3 ). Pronotal setae medially sparse golden and brown, sometimes laterally denser and white. Elytra with sparse golden and brown setae ( Fig. 1 ). Pygidium with sparse white setae, denser at base, forming dense medial patch, or sometimeswhite median vertical strip ( Fig. 4 ). Ventral surface with moderately dense white setae ( Fig. 2 ).

Head with convex frons, frontal carina slightly evident and ocular sinus deep, more than half length of eye ( Fig. 3 ). Antennomeres 1 and 3 filiform, 2 and 4 moniliform, 5–10 wider than long, 11 globular but pointed apically. Disc of pronotum strongly sulcate at basal lobe. Elytra without denticles at strial base. Hind femur on ventral margin with slightly prominent tooth (0.01–0.05 mm), not microserrate ( Fig. 5 ). Hind tibia with lateroventral carina not reaching half its length ( Fig. 6 ).

Male genitalia. Median lobe strongly sclerotized, about 5.6 times longer than wide medially, apex slightly expanded; ventral valve rounded with round apex and lateral margins convex. Internal sac with hinge sclerites short, slightly curved with apex broader; apical region without spicules; subapical region with long and dense group of short spicules; submedian region with two lateral groups of long spicules; latero-basal lobes of internal sac with spicules denser at base; basal region with spicules and denticles denser near gonopore ( Fig. 7 ). Tegmen with lateral lobes separated by emargination about 0.9 times their length ( Fig. 8 ).

Material examined. Types: Bruchus abbreviatus Say, 1824 . In the revision of Sennius, Johnson & Kingsolver (1973) indicated the type was lost. Bottimer (1968) synonymized Bruchus bivulneratus Horn, 1873 with Bruchus abbreviatus and Johnson, in the same year, designated a lectotype for Bruchus bivulneratus (Type locality : “Southern and Western States”) which is deposited in MCZ. This material was studied based on photos available in MCZ website and male genitalia illustrated in the revision of Johnson & Kingsolver (1973). Note: Until the publication of the work of Mawdsley (1993) it was believed the entire Say collection was lost, however this author recorded 56 species described by Say and deposited in MCZ. However, Bruchus abbreviatus was not listed in this paper.

Non-type (82): No locality : 1, 16 /III/[19]76 (USNM); USA: Arkansas: Washington: 1, 18 /IV/1906 (TAMU); 3, 7 /VIII/1907 (TAMU). New York: 1, no further data (TAMU). Illinois: Pope: 13, 27 /XI/[19]51, E. E. Piler. (TAMU); St. Clair: 4, Kahokia, 5/VIII/1902, G. W. Bock (TAMU). Indiana: N. Albany: 1, no further data (USNM). Ohio: Athens: 2, 5 /X/[19]38, L. P. Reynouds (CNCI). Wooster: 3, 17 /VI/2000, A. E. Miller (2, FSCA; 1, TAMU). Pennsylvania: No location : 2, 1929 (TAMU). Camphill: 11, 1923(TAMU); 1, 4 /VIII(TAMU). Kansas: Topeka: 1, Popenoe (USNM). Onaga: 1, 15 /VI/[19]23, Crevecoeur (TAMU). Missouri: No location : 1, W. G. Dietz (TAMU); 1, Chittenden (USNM). St. Louis: 1, V/[19]22 (TAMU); 4, “St. Louis - Mo.” (CNCI); Creve Coeur: 1, Lake St Louis, IX-16-94, G. W. Bock (TAMU). Virginia: 2, no further data, (1, TAMU; 1, NHRS). Fairfax: 2, 26 /IV/1928, L. J. Bottimer (CNCI); 2, 6 /XII/1928, L. J. Bottimer (CNCI). Lee: 2, Hubbard & Schwarz (USNM). Vienna: 1, 1928, L. J. Bottimer (CNCI); 3, 23 /III/[19]28, L. J. Bottimer (CNCI); 3, 2 /VI/[19]28, L. J. Bottimer (CNCI). Maryland: No location : 3, Otto Lugger (TAMU). Odenton: 1, 27 /VII/1918, H. Dietrich (TAMU). Tennessee: Nashville: 1, VIII/[19]12, Osburn. (USNM). Guyot Smoky Mountains: 1, 20 /VII/1940, Dieke (USNM). North Carolina: No locality : 1, C. W. Leng (TAMU); 1, Chevrol. (NHRS). Georgia: GarIowns: 2, 17 /VIII/[19]68, Jan Foster (USNM). Kentucky: Brooklyx: 1, Cornell U., 29/VI/1925 (TAMU); 1, Crew, (CNCI); North America: 1, Germar (NHRS); 1, Sturm. (NHRS).

Distribution. USA (Washington, New York, Illinois, Indiana, Ohio, Pennsylvania, Kansas, Missouri, Virginia, Maryland, Tennessee, North Carolina, Georgia, Arkansas, Kentucky, Missouri).

Host plant. FABACEAE : Caesalpinioideae : Senna marilandica (Linn.) Link.

Diagnosis. Sennius abbreviatus (subgroup 1) is externally similar to S. durangensis , S. medialis (subgroup 2) and S. rufomaculatus (subgroup 2) in having the pubescence regularly distributed on almost all elytra and the redorange maculae. Sennius abbreviatus differs by having most of the macula at the basal region of each elytron which in S. durangensis is more elongated occupying most of each elytron; in S. rufomaculatus the maculae are usually irregular; in S. medialis the maculae are more oval and smaller at the base and apex. Besides, S. abbreviatus differs in the distribution of pubescence on the dorsum, which is sparse in S. abbreviatus , and moderately dense in S. medialis ; in the coloration of setae on the dorsum, which is white and brown in S. abbreviatus and only white or white and gold in S. durangensis ; without dense patches on 3rd and 5th interstices in S. abbreviatus and present in S. rufomaculatus ; and in the pubescence pattern on pygidium, which is homogeneous in S. abbreviatus and S. durangensis and denser basally in S. medialis and S. rufomaculatus .

The male genitalia of S. abbreviatus is similar to that of S. rufomaculatus . Both species are placed in subgroup 1, but S. abbreviatus differs by the hinge sclerites with apex broader and slightly curved, and S. rufomaculatus with hinge sclerites broader at the base and strongly curved.

Figures

FIGURES 1 – 8. Sennius abbreviatus. 1, dorsal view; 2, lateral view; 3, head, frontal view; 4, pygidium; 5, part of hind leg, internal view; 6, hind tibia, external view; 7, 8, male genitalia: 7, median lobe with hinge sclerites (HE), others sclerites magnified and latero-basal lobes (LBL) of internal sac; 8, tegmen. AR: apical region; SMR: submedian region; SBR: subbasal region; BR: basal region.