Meibomeus juarez Romero and Johnson

Romero, Jesús & Johnson, Clarence Dan, 2002, Five New Species Of Meibomeus Bridwell From The New World With Host Records For Them And Six Named Species (Coleoptera: Bruchidae), The Coleopterists Bulletin 56 (2), pp. 182-202 : 190-192

Meibomeus juarez Romero and Johnson , new species

Male. Length (pronotum­elytra) 2.1–2.5 mm. Width 1.2–l. 5 mm. Maximum thoracic depth 1.0– 1.3 mm.

Integument Color. Integument black, not metallic; some specimens with first three or four antennal segments dark brown; eyes dark red to shiny black.

Vestiture. Moderately dense, grayish, not variegated; dense white hairs on scutellum, small apical portion of mesepisternum, and ocular sinus.

Structure. Head. Frons with fine medial longitudinal carina; eyes not sexually dimorphic, in some specimens facets coarse, about 5 rows of facets behind ocular sinus; interocular ratio about 0.15–0.31; antenna extended to about 0.8 length of elytron, pedicel about 0.25–0.75 of scape length and about 0.4–0.6 as long as segment 3, segment 11 slightly more elongate than 10, acuminate at apex.

Prothorax. Disk subcampanulate with many punctations in no apparent pattern; cervical sulcus deep, extending from near coxal cavity to 0.6 distance to pronotal midline; lateral prothoracic carina vague, extending from base to about 0.3 distance to coxal cavity; prosternum separating procoxae for about 0.5 their length; short median basal line on median basal lobe often obscured by hairs.

Mesothorax and Metathorax. Scutellum small, quadrate, bifurcate at apex; stria subequal at base, sometimes slightly abbreviated at base; elytron about twice as long as broad; striae deep, punctate; strial intervals punctulate; metasternum deep, rounded in profile; metasternum with 2 strong medial spines at base on either side of midline projecting ventrally, spines of metasternum followed by a narrow, elongate sulcus; hind femur constricted basally and apically, expanded medially to slightly more than width of coxa ( Fig. 7); inner ventral surface without longitudinal carina; lateral margin of femur in a long gentle curve to apex; inner margin armed with 4–5 small, subapical acuminate spines each about 0.3 as long as width of tibial base; tibia with ventral, lateroventral, lateral and dorsomesal glabrous carinae; dorsal surface of tibia without fossa; tibial corona with one vague lateral spinule, mucro small, about 0.1 as long as first tarsomere; tarsomere 1 with distinct ventral, lateral and mesal longitudinal carinae.

Abdomen. First abdominal sternum without polished lateral apical band; sterna 2–4 unmodified, fifth sternum elongate, 3.6–5.5 as long as fourth, gently curved at apex, not emarginate, apex produced ventrally. Pygidium with many fine punctations, wide, apex gently curved ventrad.

Genitalia. Median lobe slightly constricted on lateral margins; ventral valve acuminate apically but modified laterally with elongate projections, each projecting well beyond apex of ventral valve, distance between lateral margins of projections 3.5 times as wide as most narrow portion of median lobe, each projection with small area laterally with fine setae ( Fig. 8 ); dorsal valve rounded apically; armature of internal sac with triangular, medial sclerite near apex flanked by two large curved sclerites, internal sac lined on medial third with minute flattened spines, basal third lined with fine denticles ( Fig. 8 ). Lateral lobes cleft to 0.4 their length, each lobe curved and with medial spine about 0.2 from apex to give appearance of large, curved forceps ( Fig. 9 ).

Female. Length (pronotum­elytra) 2.2–2.5 mm. Width 1.2–l. 5 mm. Maximum thoracic depth 1.1–1.2 mm.

Similar to male except interocular ratio about 0.23–0.42, metasternum without two strong spines basally; hind femur with 4 to 5 strong subapical spines on medial margin; fifth sternum smaller 2.5–2.7 as long as fourth, pygidium less rounded apically.

Host Plants. Indigofera thibaudiana DC. : México. Oaxaca: 28 km N Pochutla , I­4­80, C.D. Johnson collector ( CDJ #1350­80 ).

Type Series. Holotype male, allotype female and paratypes: México. Oaxaca: 28 km N Pochutla , I­4­80, C.D. Johnson collector . Holotype and allotype deposited in the U.S. National Museum of Natural History , Washington, D.C., U.S.A. Paratypes deposited in the CDJ, JRN, AT, CIB and FDA collections.

Distribution. México (Oaxaca).

Discussion. This is the only species of Bruchidae that we know in which males (or females) have two strong spines on the basal portion of the metasternum. The male genitalia are very different from other species of Meibomeus ( Figs. 8, 9 ). The basal metasternal spines and structure of the male genitalia are differentiating external and internal features of this species and leave no doubt that this is a distinct species. Meibomeus juarez shares the pecten without a large tooth and with four to five small teeth on the hind femur ( Fig. 7) with M. serraticulus (Sharp) and M. viduus (Sharp) . The integument color is similar to M. hidalgoi Kingsolver and Whitehead , but M. juarez differs because its first abdominal sternum does not have a polished lateral apical band. M. juarez has a robust body shape as does the holotype of M. howdeni Kingsolver and Whitehead but the latter does not have basal metasternal spines.

Etymology. This species is named for our friend Betty Juarez. The specific epithet is a noun in apposition to Meibomeus .

Figures

Figs. 8–9. Meibomeus juarez male genitalia. 8) Median lobe; 9) lateral lobes.