Timorus sarcophagoides

Vanin, Sergio A. & Guerra, Tadeu J., 2012, A remarkable new species of flesh-fly mimicking weevil (Coleoptera: Curculionidae: Conoderinae) from Southeastern Brazil, Zootaxa 3413, pp. 55-63 : 56-59

Timorus sarcophagoides , sp nov.

( Figs. 1 ─15)

Type material. Brazil. Holotype male (dissected). Minas Gerais, "Santana do Riacho - Serra do Cipó 43o35'W 19o17'S, altitude 1100–1300m, XII.2007 T.J. Guerra col.; campo rupestre, on Psittacanthus robustus , Loranthaceae ", ( MZSP). Paratypes: same data as holotype, 4 ♂ (1 dissected), 7 ♀ (2 dissected) ( MZSP); Minas Gerais, "Lagoa Santa, 26.XI.1960, Araújo e Martins", 1 ♀ ( MZSP). Rio de Janeiro, "Rio de Janeiro (Corcovado), X. 1957, M. Alvarenga", 1 ♂ dissected ( MZSP).

Description. Length (rostrum excluded), male: 6.3–8.4 mm; female: 8.7–10.0 mm. Body rhomboidal. Integument black, vestiture formed by colored scales; frons ochreous, yellow above and behind eye; middle longitudinal carina and lateral triangular-shaped area behind eye glabrous and shiny-black; rostrum with whitish scales, denser in basal half. Prothorax with one broad patch of dense carmine scales on anterior margin, extending down to flanks; yellow scales forming irregular fringe almost bordering each carmine patch laterad and posteriad, and less dense yellow scales forming three pairs of spots, one elongate oval on each side of median longitudinal pronotal carina and two irregular-shaped behind carmine patch; basal third of elytra with ochreous and yellowish-white scales concentrating densely on interstriae 2, 4, 6 and 8, while interstriae 1, 3, 5 and 7 blackish, resulting in contrasting pattern of light and dark irregular stripes; epipleura with two dark spots. Ventral margin and legs covered by elongate whitish scales; with oval patch of ochreus scales on each side, extending from ventrite II to base of ventrite V, surrounded by yellow scales. Metespisternum and base of ventrites I and II glabrous.

Head ( Figs. 5 ─7) Eyes oval, acuminate inferiorly, inner margin sinuous, large and well separated, narrowest distance in front about 0.9X width of rostrum at base; inferiorly more separated by distance about 1.2X width of rostrum at base; front shallowly concave between eyes, with middle carina extending from base of head to central fovea. Rostrum slightly longer than pronotum, moderately stout, weakly curved, feebly depressed in basal half, with dorsal carina more developed in males, with tuberculiform process at base; antennal insertion behind middle. Antenna with scape clavate, not reaching base of eye, shorter than funicle; funicle with seven antennomeres; antennomeres 1st and 2nd with similar lengths; 3rd and 4th subequal, about 0.7X as long as 2nd, 5th to 7th subequal, about as long as broad, slightly shorter than 4th; club oval, about as long as length of three preceding antennomeres combined, basal antennomere about half as long as club length.

Prothorax ( Figs. 1 ─4) subtrapezoidal, rather convex, transverse, slightly broader than long (1.1–1.2X); rounded at posterior angles, wider near posterior fifth and there converging gradually towards weakly constricted apex; anterior margin straight with acuminate angles, posterior margin bisinuous and with basal lobe produced and emarginate posteriad before scutellum; dorsal middle carina not attaining frontal and hind margins, anterior half of carina sharp, posterior half wider, flattened and sulcate at middle; pronotal disc with depressed areas smoother, surrounded by densely rugosely punctate and bare areas. Postocular lobes prominent.

Scutellum exposed, free, rounded, tuberculiform, with withish scales.

Elytra ( Figs. 1 ─4) 1.3─1.4 times as long as broad, wider than prothorax, elongate, margins gently converging posteriorly and abruptly constricted near apices, sharply margined externally by acute carina on intestriae 9; humeri prominent; apices obliquely truncate, each produced into a minute spine. Elytral striae poorly developed, each puncture with small scale inside; alternate interstriae 3, 5, 7 and 9 with sharp, bare and shiny carina from base to elytral declivity; alternate interstriae 2, 4, 6 and 8 with feeble carina; interstriae 1 and 2 adjacent to scutellum slightly depressed; margin of elytron recovered by slender yellowish scales, outer margin minutely crenulated

Venter ( Fig. 8 ). Rostral canal formed by prosternum and sides of forecoxae extending to mesosternum. Prosternum with deep canal, bordered by sharp carina reaching the anterior region of forecoxae; inner side of each forecoxae prolonged posteriad by flattened process forming continuing margin of rostral canal. Mesosternum declivous posteriad, depressed anteriad at middle accommodatingtip of rostrum. Metaventrite convex.

Abdomen with ventrites 3 and 4 equal in length. Pygidium covered.

Legs ( Figs. 1, 3 ). Femora curved, compressed and weakly clavate, carinate on both inner and outer surfaces and armed beneath with oblique tooth; hind femora larger than fore and midfemora, their apices just exceeding posterior margin of ventrite 3. Tarsal claws simple.

Male terminalia. Aedeagus (Figs. 14, 15): median lobe slender, feebly curved, 3.3 X as long as wide (median struts excluded), lateral margins converging gradually from base to near apex, then more strongly convergent and ending in triangular point; median lobe about 1.3 X as long as median struts; endophallus with a pair of uncinate sclerites. Tegmen as in Figs. 12, 13.

Female terminalia. Coxites (Fig. 10) elongate, weakly sclerotized; stylus apical, elongate, cylindrical, slightly curved outwards, apex rounded and setulose; sternite VIII elongate (Fig. 11), setulose, apex truncate. Spermatheca (Fig. 9) U-shaped, ramus and collum closely approximate.

Etymology: Greek, sarcophagoides , like sarcophagid flies.

Type-locality: Brazil, Minas Gerais, Santana do Riacho - Serra do Cipó 43o35'W 19o17'S, altitude 1100–1300m ASL.

Geographic distribution: the new species is represented in Southeastern Brazil, in the states of Minas Gerais and Rio de Janeiro.

Biology. Timorus sarcophagoides was found exclusively on live, adult and reproductive woody mistletoes, Psittacanthus robustus Mart. (Loranthaceae) ( Fig. 16 ). The new species is a specialized phytophage feeder on P. robustus in both adult and larval stages. During two consecutive years of observation adult weevils were found exclusively from November to February, overlapping the flowering period of the host plant species. Adult weevils fed mostly on flower buds (Fig. 17). They usually pierced receptacles chewing soft tissues of the ovaries, but also on the tips of closed buds feeding on pollen grains and stamens. Weevils also fed on soft tissues in leaf axils (Fig. 18). In January and February females were observed chewing tiny roles in the haustorial root of the host plant (Fig. 19) where they oviposited (Fig. 20). The larva is rhizophagous, developing as a borer inside the haustorium of the host plants (Fig.21). Larvae were found from March to September, during the dry season. Pupae were found exclusively inside haustorial roots in October, suggesting that the metamorphosis ends just before the beginning of the rainy season. Adults emerged from mistletoes in November 2009, coinciding with the beginning of the host plant blooming period. While moving, weevils perform unusual jerking movements of the legs and a stereotypical leg scrubbing behavior mimicking the behavior of flesh-flies. Disturbed weevils usually hide on the underside of leaves or shoots moving in the opposite direction of the threat stimuli. More effective capture attempts usually induced weevils to drop off of the host plants. Hand-captured individuals performed thanatosis (Fig. 22). The new species is diurnal and at night individuals were observed resting completely motionless on leaves. Adult weevils walk throughout the whole area of the host plant, rarely leaving mistletoes by flight. While chewing, weevils inserted their long rostrum in host tissues, and this feeding behavior made it difficult for them to drop off or move away quickly, probably making them more susceptible to attacks of natural enemies.

Figures

FIGURES 8 ─ 15. Timorus sarcophagoides, sp. nov. FIGURES 8 ─ 11, paratype from Santana do Riacho: 8, body, ventral view, head, median and hind legs omitted; 9, spermatheca, lateral view; 10, coxites and styli, dorsal view; 11, sternite VIII, ventral view; FIGURES 12 ─ 15, holotype, male terminalia: 12, tegmen, lateral view; 13, tegmen, dorsal view; 14, median lobe, lateral view; 15, median lobe, dorsal view.

FIGURES 16 ─ 23. FIGURE 16, host plant Psittacanthus robustus Mart. (Loranthaceae); 17 – 22, Timorus sarcophagoides, sp. nov; 17, weevil feeding on flower receptacle and detail of pierced flower bud; 18, weevil on leaf axils; 19, female chewing host plant; 20, oviposition placed in the haustorium; 21, weevil larva developing inside host plant; note the excavated tunnel inside haustorium; 22, thanatosis behavior of a captured weevil; 23 a flesh-fly model (Sarcophagidae) perched on host plant.

FIGURES 1 – 7. Timorus sarcophagoides, sp. nov., habitus: 1, male holotype (length: 8.4 mm), lateral view; 2, male holotype, dorsal view; 3, female paratype from Santana do Riacho (length: 8.7 mm), lateral view; 4, female paratype, dorsal view; male paratype from Rio de Janeiro (length 6.3 mm), detail of head and pronotum, lateral view; 6, same, frontal view of head and rostrum; 7, female paratype from Santana do Riacho, frontal view of head and rostrum.