Sennius lawrencei Johnson, 1977

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 : 514-515

Sennius lawrencei Johnson, 1977

( Figs 29–37 )

Sennius lawrencei Johnson, 1977: 121 (description, figures, type designation, taxonomy, distribution, host); Johnson & Kingsolver 1981: 419 (catalog, distribution); Udayagiri & Wadhi 1989:104 (catalog).

Redescription. Dimension. BL: 2.0–2.6 mm; BW: 1.2–1.8 mm.

Integument color. Head generally black, sometimes with mouthparts red-orange and/or small red-orange postocular macula ( Fig. 31 ); antennomeres 1–4 red–orange, 5 red-orange to reddish brown, 6–11 reddish brown, ventral surface of segments red-orange ( Figs 30, 31 ). Elytra completely red-orange, red-orange with narrow external border of dark brown to black, or black with red-orange rounded macula on submedian region, which extends from 3rd to 9th interstices, occupying more than half of each elytron ( Fig. 29 ). Pronotum and prosternum dark brown to black, remaining thorax red-orange to black; fore and mid leg red-orange, except for brown to dark brown tarsus; hind leg entirely black to entirely red-orange ( Fig. 30 ).

Pubescence. Head with small dense patch of white setae posterior to post-ocular lobe, remainder with sparse white setae; labrum with scattered golden setae, denser apically ( Fig. 31 ). Pronotum with white, golden and brown setae ( Fig. 29 ). Dark specimens: Pronotum with gold and brown setae, dense white patch at basal lobe and part of lateral third from 3rd strial interval to humerus. Elytra with golden and brown setae, except for vertical strip on 1st strial interval and part of 2nd strial interval with moderately dense white setae ( Fig. 29 ). Ventral surface with moderately dense white setae, except setae denser on base of mesepimerum, posterior margin of metepisternum and distal region of hind coxa ( Fig. 30 ). Pygidium with even and moderately dense white setae, eventually denser on median line, extending from base to apex ( Fig. 32 ).

Head with frons convex, frontal carina present and ocular sinus deep, about half length of eye ( Fig. 31 ). Antennomeres 1 and 2 moniliform, 3 and 4 filiform, 5–10 wider than long, 11 globular but pointed apically. Disc of pronotum strongly sulcate at basal lobe. Elytra with denticles at base of 2nd and 4th strial ( Fig. 33 ). Hind femur on ventral margin with very prominent tooth (0.07–0.12 mm), microserrate ( Fig. 34 ); hind tibia with lateroventral carina extending half its length ( Fig. 35 ).

Male genitalia. Median lobe strongly sclerotized, about 4 times longer than wide medially, apex slightly expanded; ventral valve triangular with truncate apex and lateral margins concave. Internal sac with hinge sclerites long, strongly curved and thin; apical region without spicules; subapical region with short and dense group of spicules; submedian region with two elongated and lateral groups of long spicules; latero-basal lobes of internal sac with dense and long spicules; basal region with denticles and spicules not denser near gonopore ( Fig. 36 ). Tegmen with lateral lobes separated by emargination about 0.8 times their length ( Fig. 37 ).

Material examined. Types (4): Sennius lawrencei Johnson, 1977 . Holotype and Allotype not examined, deposited in CNCI, with the labels: “ Panama. Canal Zone: Frijoles, 24-4-64, reared seeds Cassia reticulata, L. J.

Bottimer collection # 119g. CNC # 15059”. Four paratypes studied, deposited in USNM with labels: PAN: Colon: 2, “ Gamboa \ PANAMA C. Z. \ III-4-1964 \ L. J. Bottimer” (White) “Reared seeds \ Cassia reticulata ” (White) “Emerged by \ III-21-64 ”(White) “L. J. Bottimer \ Collection \ Nº 122J”(White) “ PARATYPE ”(Blue) “ Sennius \ lawrencei Johnson \ det C. D. Johnson”(White) (USNM); 2, “ Gamboa \ PANAMA C. Z. \ I-24-1964 \ L. J. Bottimer” (White) “Reared seeds \ Cassia reticulata ”(White) “Emerged by \ II-7-64 ”(White) “L. J. Bottimer \ Collection \ Nº 119G”(White) “ PARATYPE ”(Blue) “ Sennius \ lawrencei Johnson \ det C. D. Johnson”(White) (USNM). Note: The information on holotype and allotype labels are from Johnson (1977) and the paratypes studied are part of the type material designated in the same paper. In addition to the museums mentioned above, others paratypes were deposited in CNCI, CAS and MCZ.

Non-type (7): PAN: Colon: Zona del Canal: 3, 3 /04/1985, M. Baca, Cassia reticulata (TAMU). BRA: Amazonas: Manaus: 4, 09 /VII/2002, A. Menezes Jr., Senna sp. (DZUP).

Distribution. PAN (Colon). New record —BRA (Amazonas).

Host Plant. FABACEAE : Caesalpinioideae : Senna reticulata (Willd.) Irwin & Barneby.

Diagnosis. The specimens of S. lawrencei with black elytra each with red-orange rounded macula superficially resembles S. rufomaculatus (subgroup 1). The male genitalia of S. lawrencei is more similar to S. rufomaculatus and S. nappi (both subgroup 1) however S. lawrencei differs externally from S. nappi by the lack of a horizontal stripe of white setae on the median basal region and from S. rufomaculatus by the lack of a white setal patch at the base of the interstices. The male genitalia in these three species are similar, but the internal sac of S. lawrencei lacks spicules in the apical region (present in S. rufomaculatus and S. nappi ), the subapical region has one short group of spicules (two long group of spicules in S. rufomaculatus and three in S. nappi ) and the submedian region has two elongated, lateral groups of long spicules ( S. rufomaculatus with four, grouped in pairs, and S. nappi with three, two lateral and one medially).

Figures

FIGURES 29 – 37. Sennius lawrencei. 29, dorsal view; 30, lateral view; 31, head, frontal view; 32, pygidium; 33, base of elytra strial; 34, part of hind leg, internal view; 35, hind tibia, external view; 36, 37 male genitalia: 36, median lobe with hinge sclerites, others sclerites magnified and latero-basal lobes of internal sac; 37, tegmen.