Magnoculus obscurus Olivier, 1885

Campello, Lucas, Vaz, Stephanie, Mermudes, Jose R. M., Ferreira, Andre L. D. & Silveira, Luiz F. L., 2022, Comparative morphology and key to Amydetinae genera, with description of three new firefly species (Coleoptera, Lampyridae), ZooKeys 1114, pp. 131-166 : 131

publication ID	https://dx.doi.org/10.3897/zookeys.1114.77692
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scientific name	Magnoculus obscurus Olivier, 1885
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Figs 17 View Figure 17 , 18 View Figure 18 , 19 View Figure 19 , 20 View Figure 20 , 21 View Figure 21 , 22 View Figure 22 , 23 View Figure 23

Megalophthalmus obscurus Olivier, 1885: 146.

Magnoculus obscurus (Olivier, 1885)- Constantin 2011: 153; Silveira et al. 2021: 283, 286, 289.

Diagnosis.

Elytra with inner margin dehiscent (i.e., sinuose inner margin) at posterior 1/3 (Fig. 17C View Figure 17 ); pronotum semilunar, with rounded and obtuse posterolateral angles (Fig. 19A, B View Figure 19 ), 2 × wider than long; frons raised (Fig. 18D View Figure 18 ); eyes separated by the same length of maxillary palpomere III (Fig. 18B View Figure 18 ); antennomere III as long as wide (Fig. 18G View Figure 18 ); antennae shorter than 0.5 × body length (Fig. 17A-C View Figure 17 ); posterior margin of mesoscutellum straight (Fig. 20A View Figure 20 ); phallobase symmetrical (Fig. 23A-H View Figure 23 ); sternite IX symmetrical (Fig. 23I View Figure 23 ); pygidium with posterior margin bisinuate (Fig. 23K View Figure 23 ).

Redescription.

Male. Coloration. Antennae dark brown (Fig. 18G, H View Figure 18 ); pronotum brown, with two sclerotized raised tubercles dark brown on the posterior 1/2 (Fig. 19A, B View Figure 19 ); elytron dark brown (Fig. 21A-C View Figure 21 ); abdomen completely dark brown (Fig. 22A-C View Figure 22 ). Head. Capsule 1.5 × wider than long (Fig. 18A View Figure 18 ); vertex convex (Fig. 18C View Figure 18 ); eyes separated by 2/3 of head width in frontal view (Fig. 18C View Figure 18 ); frons raised (Fig. 18D View Figure 18 ); labrum connate to fronto-clypeus, frontoclypeo-labral suture obliterate (Fig. 18C View Figure 18 ); antennal insertions rounded (Fig. 18C, D View Figure 18 ), separated by 0.5 × labrum width. Antennae flabellate, lamellae stiff and laterally compressed, with 11 antennomeres (Fig. 18G, H View Figure 18 ), as long as 1/3 of body length (Fig. 17A-C View Figure 17 ); pedicel 2 × wider than long (Fig. 18G, H View Figure 18 ), III-V subequal in length, V-IX subequal in length, IX-X subequal in length. Maxillary palp with four palpomeres (Fig. 18B View Figure 18 ), II-IV subequal in length, III 2 × longer than I. Labial palp with three palpomeres (Fig. 18B View Figure 18 ), I-II subequal in length, III 2 × longer than II. Occipital foramen subcordiform in posterior view (Fig. 18E, F View Figure 18 ). Thorax. Pronotum semilunar (Fig. 19A-D View Figure 19 ), almost 2 × longer than head length in ventral view (Fig. 17A View Figure 17 ), 2 × wider than long in dorsal view (Fig. 19A View Figure 19 ), with contiguous and equidistant punctures along the entire surface, except for two sclerotized raised tubercles on the posterior 1/2, equidistant from sides (Fig. 19A, D View Figure 19 ); hypomeron 2 × longer than tall (Fig. 19C View Figure 19 ); prosternum wider than 1/5 of pronotum width in dorsal view (Fig. 19B View Figure 19 ). Elytron slightly dehiscent (i.e., sinuose inner margin), subparallel-sided (Fig. 21A-C View Figure 21 ). Hind wing (Fig. 21D View Figure 21 ) with radial cell evanescent, 2 × wider than long; vein r3 as long as 1/4 r4 length, vein CuA1 absent; vein CuA3+4 present; vein J as long as 1/3 the length of vein AP3+4. Metanotum as long as wide, posterior margin emarginate medially, allocrista distinct (Fig. 20B View Figure 20 ). Mesoventrite sclerotized (Fig. 20B View Figure 20 ), posterior margin rounded; suture between mesoventrite and mesanepisternum visible (Fig. 20C View Figure 20 ), mesendosternum with two irregular, flap-like projections (Fig. 20E View Figure 20 ); metaendosternum spatulate, diamond-shaped (Fig. 20D View Figure 20 ). Tibial spurs absent (Fig. 21E-G View Figure 21 ), tarsus I>V>IV>II=III (Fig. 21E-G View Figure 21 ). Abdomen. Lanterns occupying almost the entire area of sternite VI and VII (Fig. 17A View Figure 17 ); sternites II-VII with sides rounded (Fig. 22A View Figure 22 ), II, III, VI and VII with posterior margin medially emarginate; sternite VIII mucronate (Fig. 23J View Figure 23 ); sternite IX symmetrical (Fig. 23I View Figure 23 ), 1.5 × longer than wide, posterior margin rounded. Pygidium 1.5 × wider than long (Fig. 23K View Figure 23 ), sides rounded, posterior margin bisinuate (Fig. 8F View Figure 8 ), posterolateral angles obtuse, central 1/3 extending slightly longer than posterolateral angles (Fig. 23K View Figure 23 ). Phallus with a dorsal and ventral plate (Fig. 23H, I View Figure 23 ) dorsal plate acuminate from apical 1/2 on, skewed to the anatomical left (i.e. left of the specimen), extending about a 1/4 longer than ventral plate towards the base (Fig. 23A, B, F, G View Figure 23 ), ventral plate bilobed (Fig. 23B-E View Figure 23 ), lobes spoon-shaped and separated by a deep cleft reaching basal 2/5, projected dorsolaterally to right under dorsal plate, dorsal plate extending a 1/3 beyond parameres; parameres symmetrical and spatulate (Fig. 23A, D, F, H View Figure 23 ), anterior margin rounded, apically separated from each other (i.e., not fused), and 1/2 shorter than the phallus (Fig. 23A View Figure 23 ); phallobase symmetrical (Fig. 23A View Figure 23 ).

Females and immature stages. Unknown.

Biology.

Fourteen individuals were collected in hilly areas in Ilha Grande State Park between 160-345 m a.s.l. Six specimens were collected using Malaise traps: three at 160 m a.s.l. in August 2017, December 2017, and January 2018; two at 170 m a.s.l. in November 2017 and April 2018; one at 345 m a.s.l. in August 2017. In addition, nine specimens were collected by active searches in July 2017 (five specimens), September 2017 (two specimens), and July 2018 (two specimens). Ma. obscurus has a yellowish-green glow, and males often fly between 0.1 and 4 m a.s.l., sometimes reaching up to approximately 7 m a.s.l. towards the forest canopy. Adults are apparently active in the early twilight hours. About five to ten males were observed flying close together in the same visual field.

Remarks.

Magnoculus obscurus is the second species of genus to be redescribed (see Zaragoza-Caballero 1995 for redescription of Ma. cf. guatemalae ). The few species recently studied and illustrated in detail by Constantin (2011) and Zaragoza-Caballero (1995) allowed us to find interesting commonalities and differences among Magnoculus species. For example, Ma. obscurus shares the following characteristics with its congeners: elytra with three raised costae; pronotum with two sclerotized raised tubercles on the posterior 1/2 and posterior angles obtuse; and sternite VIII mucronate.

A comparison of Ma. obscurus with species described and illustrated in detail by Constantin (2011) and Zaragoza-Caballero (1995) is given here, as follows: antennae smaller than 1/2 body length, similar to Ma. dalensi and Ma. touroulti , but longer than 1/2 body length in Ma. brulei , Ma. dewynteri , Ma. poirieri , and Ma. guatemalae ; flabellum of antennomere III as long as pronotum length, similar to Ma. touroulti and Ma. guatemalae , but 0.5 × shorter in Ma. dalensi , ~2.5 × longer in Ma. brulei , Ma. poirieri , and Ma. dewynteri ; eyes ventrally close-set in Ma. obscurus , similar to Ma. touroulti and Ma. brulei , but not in Ma. guatemalae and Ma. dewynteri (undescribed in Ma. dalensi and Ma. poirieri ); gular margins contiguous in Ma. obscurus , Ma. guatemalae , and Ma. touroulti , but open in Ma. dewynteri (no information for Ma. dalensi , Ma. poirieri , and Ma. brulei ); pronotum semilunar, 2 × wider than long, similar to Ma. touroulti , Ma. brulei , and Ma. guatemalae , but as wide as long in Ma. dalensi , triangular and as wide as long with anterior margin rounded in Ma. poirieri and Ma. dewynteri , completely yellow in Ma. poirieri , brown with an orange anterior spot in Ma. dewynteri , and completely dark brown in Ma. obscurus , Ma. brulei , Ma. dalensi , and Ma. tourolti . Pronotal disc with two sclerotized raised tubercles on the posterior 1/2, similar to Ma. brulei , Ma. poirieri , Ma. dewynteri , and Ma. tourolti , which are reduced in Ma. dalensi . Pygidium bisinuate in Ma. obscurus , as in Ma. dalensi and Ma. guatemalae , but semilunar in Ma. brulei , Ma. dewynteri , Ma. poirieri , and Ma. touroulti . Aedeagus of Ma. obscurus asymmetrical, as in Ma. guatemalae , Ma. poirieri , and Ma. touroulti , but symmetrical in Ma. brulei , Ma. dewynteri , and Ma. dalensi .

Lectotype (designated herein).

Bearing the labels: "SYNTYPE. Megalophthalmus . Megalophthalmus obscurus . Olivier, 1885. MNHN, Paris-co E. Olivier" [aged red label, typewritten]; “Muséum Paris. Coll. E. Olivier" [green label, typewritten]; “Brésil.” [aged white label, typewritten]; “Sahlberg.” [aged white label, typewritten]; " Megalophthalmus obscurus . Brésil ‘oliv’ [aged white label with green margins] (MNHN, ex. coll E. Olivier; Suppl. material 1: Fig. S2).

Olivier mentioned examining specimens in his and also in Oberthür’s collections. It is unclear how many specimens Olivier examined, and we did not have the opportunity to carefully look for them at the MNHN.

Other materials examined.

Brazil • Rio de Janeiro: Angra dos Reis: Parque Estadual da Ilha Grande), Pico do Papagaio ; 4 ♂ ; 29 Jul. 2017; L. Silveira leg. (DZRJ) • 23°08'51.5"S, 44°10'52.4"W; 345 m a.s.l.; 1 ♂; Aug. 2017 (DZRJ) • 23°10'05.7"S, 44°11'04.0"W; 170 m a.s.l.; 1 ♂, Sep. 2017 (MNRJ) • same data as for preceding; 1 ♂ , Apr. 2018 (MNRJ) • same data as for preceding, Estrada para Dois Rios ; 2 ♂ ; 22 Nov. 2017 (MNRJ) • same data as for preceding; 2 ♂ ; Jul. 2018 (MNRJ) • same data as for preceding, Poco do Soldado ; 23°10'04.7"S, 44°11'03.5"W; 160 m a.s.l.; 1 ♂ GoogleMaps ; Dec. 2017 (DZRJ) • same data as for preceding; 1 ♂ GoogleMaps ; Aug. 2017 (MNRJ) • same data as for preceding; 1 ♂ GoogleMaps ; Jan. 2018 (MNRJ).