Pachydema megalops Micó, 2009

Micó, Estefanía & Galante, Eduardo, 2009, A new species of Pachydema Laporte (Coleoptera: Scarabaeoidea: Scarabaeidae: Melolonthinae: Pachydemini) from the Canary Islands, Zootaxa 2284, pp. 41-47 : 42-45

Pachydema megalops Micó sp. nov.

( Figs. 1–10 )

Description. Male: Length 12.1–13.0 mm. Dorsum uniform light brown. Clypeus with anterior border emarginate, margin clearly elevated ( Fig. 1 ); 2.5–2.8 times wider than long. Frontoclypeal suture slightly sinuate and partially hidden by punctures. Frons 1.0–1.3 times wider (at the middle) than long, moderately to densely punctate. Frons 2 times wider than dorsal diameter of eye. Eye canthus short and thin, with 13–20 setae. Antenna ( Fig. 2 ) with 10 antennomeres; antennal club brownish yellow, setose, with 5 antennomeres 1.5–1.9 times longer than the preceding 4 antennomeres combined. Galea and lacinia of maxilla ( Fig. 3 ) with well-developed teeth; base of galea strongly sinuate; last maxillary palpomere ( Fig. 4 ) longer than the two preceding palpomeres combined, wider than 2.1–2.9 times the wide of preceding palpomere. Sensory spot of last maxillary palpomere wide, flat, or nearly convex. Mentum ( Fig. 5 ) with a circular, deeply concave smooth area surrounded by slender, brownish yellow setae; apex flat and notched; apex with a group of several setae on each side. Pronotum ( Fig. 6 ) 1.5 times wider than long. Pronotal disc with deep, round punctures irregularly distributed (from sparse to confluent); anterior angles acute, lateral and inferior borders smoothly angled; apical margin with long setae. Lateral margin of scutellum bordered by more or less deeply impressed groove, mostly broken at the tip ( Fig. 7 ). Elytra convex with maximum width just behind the middle; surface moderately punctate, more dense along first interstria; elytral striae smoothly defined; humeral callus rounded; setae present at base and along lateral margins. Metasternum with long, dense, brownish yellow setae. Protibia tridentate, with an apical spur. Mesotibia and metatibia with two subequal apical spurs. Metatibia internal border dilated ( Fig. 8 ); transversal carina of dorsal face interrupted at the middle. Protarsomeres 2–3 slightly widened ( Fig. 9 ); venter covered by dense and short pilosity. Metatarsus 1.6–1.7 times longer than metatibia. Pygidium nearly convex with fine and disperse punctures. Parameres longer than the rest of aedeagus; slightly arrow shaped at apical third ( Fig. 10 ).

Variability. The pronotum punctation is variable. Range of variation in total size and other measures is detailed in the description.

Material examined (4 specimens). Holotype male: SPAIN, Gran Canaria, Las Huesas, January, 24, 1989. Rafael García B. Leg. Paratypes (three males): same data as Holotype. Holotype is deposited in Rafael García collection. Paratypes are deposited in R. García collection, DZUL, and CEUA.

Natural history data. All specimens were captured in January, at an elevation of 75 m in an abandoned orchard. Specimens were hidden under stones (R. García, Santa Cruz de la Palma, Tenerife, Spain; personal communication).

Remarks. The large eyes of this species are similar to P. castanea (Brullé) and P. l e s n e i Peyerimhoff. However, characters such as the presence of punctures in the scutellum disc, the metatibia internal border not dilated at middle (as in Fig.17 a), and the parameres forcep shaped ( Fig. 16 e–h) are shared by P. castanea , P. fuscipennis (Brullé) , P. obscurella (Wollaston) , and P. gomerae López-Colón and clearly separate this group of species from P. megalops sp. nov. In fact, the new species seems to share more characters with other species also present in Gran Canaria, such as P. bipartita and P. l e s n e i. The shape of parameres is very similar in P. bipartita (Brullé) and P. m e g a l o p s (see Figs. 10 and 16 l), however eye size can be used to easily distinguish these species. P. megalops and P. l e s n e i share a similar eye-size character but are distinguishable by other characters such as the shape and size of the apical maxillary palpomere, the shape of third and fourth antennomeres, and the shape of parameres (see Figs. 2, 4, 10 and Figs. 13 c, 15c, 16i).

Etymology. The specific epithet is a Latinized Greek noun in apposition (invariable), meaning "large eye", referring to the large eyes exhibited by this species.

Figures

FIGURES 1 – 10. Pachydema megalops Micó sp. nov. 1 — Head. 2 — Antenna. 3 — Galea and lacinia of maxilla. 4 — Apical maxillary palpomere. 5 — Mentum. 6 — Pronotum. 7 — Scutellum. 8 — Metatibia. 9 — Protarsus. 10 — Parameres, dorsal view. Scale bar in mm.

FIGURES 16 – 17. 16 — Parameres, dorsal view: a) P. obscura, b) P. tinerfensis, c) P. fortunatorum, d) P. jeannei, e) P. castanea, f) P. fuscipennis, g) P. obscurella, h) P. g o m er a e, i) P. l e s n e i, j) P. keithi, k) P. m e n i e r i, l) P. bipartita, m) P. wollastoni, n) P. navatteae. 17 — Metatibia. a) P. obscurella, b) P. ke i t h i. Scale bar in mm.

FIGURES 11 – 15. 11 — Mentum: a) P. ob s cu ra, b) P. ob s cu rell a, c) P. keithi. 12 — Galea and lacinia of maxilla: a) P. obscura, b) P. obscurella. 13 — Antenna: a) P. o b s c u r a, b) P. oromi, c) P. l e s n e i. 14 — Head: a) P. o b s c u r a, b) P. oromi, c) P. castanea. 15 — Apical maxillary palpomere: a) P. fuscipennis, b) P. o b s c u re l l a, c) P. l e s n e i, d) P. keithi, e) P. m e n i e r i, f) P. wollastoni, g) P. bipartita, h) P. navatteae. Scale bar in mm.