Platynectes (Platynectes) garciai, Gustafson & Short & Miller, 2016

Gustafson, Grey T., Short, Andrew E. Z. & Miller, Kelly B., 2016, New species of diving beetles in the subgenus Platynectes s. str. from the Guiana Shield (Coleoptera: Dytiscidae: Agabinae), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 79-102 : 88-90

Platynectes (Platynectes) garciai sp. nov.

( Figs 6 , 11 , 15 , 16 )

Type material. HOLOTYPE: J, “ VENEZUELA: Bolivar State / 4°31′19.1″N, 61°31′34.0″W, 860 m / Gran Sabana, E Pauji , Salto Catedral / 16.vii.2010; leg. Short, Tellez, Arias / marsh/stream; VZ10-0716-03 A [white label, typed black ink]”, “ SEMC0909157 / KUNHM-ENT [white label with barcode, type black ink]” ( MIZA) . PARATYPES (18 spec.): same a holotype except: 1km E Pauji:trib. Of Rio Pauji , N4°28.782′ W61°34.904′, 853 m, 16.vii.2010, along stream, VZ10-0716-01 A, SEMC0906675 (1 spec. SEMC) ; same as previous except: Pauji: Esmeraldes , N4°28.233′ W61°35.559′, 867 m, 16.vii.2010, detrital pools by forested stream, VZ10-0716-02 A, SEMC0908246 , SEMC0908253 , SEMC0908282 (3 spec. SEMC) ; same state as previous except: Rio Aponwao , N5°50′49.2″ W61°28′2.4″, 1340 m, 31.vii.2008, leg. A. Short, M. Garcia, small streamlet, AS-08-060b, SM0830156 (1 spec. SEMC) ; “ Venezuela: Bolivar, Gran Sabana, Pauji: Esmeraldes , 867 m, 16.vii.2010, 4°28.233′N 61°35.559′W, Short,Arias, Tellez (VZ10- 0716-02 A (ABTC-02189)”, “MB 6288” (1 spec. ZSMG), “ GUYANA: Region XIII, 5°10.514′N, 59°28.970′W, 400 m, Kaieteur Natʼl Park, trail by guest house ; small forest stream, leg. A. Short ; 15.iii.2014, GY14-0315-03 A, SEMC1329009 – SEMC1329012 , SEMC1329014 – SEMC1329016 , SEMC1329020 , SEMC1329022 , SEMC1329025 (10 spec. SEMC) ; same as previous except:rock savanna, large seepage area; leg. A. Short , 16.iii.2014: GY14-0316- 01C, SEMC1313872 – SEMC1313873 (2 spec. SEMC) .

Diagnosis. Larger in size (6.6–6.7 mm in length), evenly oval in dorsal habitus, elytron with very subdued maculae, at most four yellow spots present on elytron, two most evident being parascutellar, others variously developed, especially humeral spots.

Description. Size. Male: TL = 6.6–6.7 mm, TL-h = 6.0– 6.1 mm, TW = 4.1–4.2 mm; female: TL = 6.6 mm, TL-h = 6.0 mm, TW = 4.2 mm.

Body evenly oval, lateral margins evenly curved and continuous between pronotum and elytron ( Fig. 6 ).

Coloration ( Fig. 6 ). Head orange grading into diffuse, light yellow region medially on frons and testaceous to black mediad and posteriad of eyes, in some specimens extending anteriorly around eye to lateral margin of frons. Pronotum broadly black or testaceous medially along anterior and posterior margins, black regions meeting medially in lighter, testaceous transverse band; posterolateral margins of pronotum narrowly black, lateral surfaces yellow, extending medially to dark region; scutellum darkly colored, often black. Elytron testaceous, with narrow, lateral diffuse pale band and four variously developed yellow spots, one parascutellar most evident, one humeral least evident, one slightly posterior of middle near lateral margin, one anteapically. Appendages of head, legs and ventral surfaces, including elytral epipleuron, pale orange to reddish, somewhat darker on thoracic sterna and metacoxae; apical abdominal tergite yellow.

Structure and sculpture. Head broad and short, anterior clypeal margin broadly rounded; entire dorsal surface of head with small highly irregular cells, each cell with fine punctures, additional irregular covering of fine punctation throughout. Pronotum broad and short; lateral bead distinct and broad, evenly curved, about width of antennomere V; surface shiny, covered with fine microreticulation of irregular cells, cells with fine punctures, additional punctation consisting of a row of large coarse punctures on anterior and posterior margin, punctures separated by ca. 0.5–1× diameter of a puncture anteriorly, posteriorly mostly effaced by reticulation, punctures irregularly present posterolaterally, absent medially. Elytron with lateral margins evenly curved to slightly angulate apex, lateral epipleural carina distinctly visible throughout length; surface covered with weakly impressed, but distinct microreticulation of large irregular cells, cells also with fine punctures; elytral epipleuron slender, evenly tapered to apex. Prosternum medially moderately long, longitudinally swollen; prosternal process broad, lateral margins broadly curved to somewhat pointed apex, surface flat to slightly curved, smooth. Metaventrite with anterior process broad, with broadly curved emargination for reception of prosternal process; lateral wings broad, WC/WS = 4; surface smooth, microreticulation mostly effaced, punctation nearly imperceptible. Fore- and midlegs slender, surfaces punctate, protibial apices with largest spine longer than protarsomeres I+II; mesotibal apices with longest spine shorter than length of mesotarsomeres I+II, extending 1/2 mesotarsomere II length, mesotarsal spurs elongate slender, slightly sinuate, nearly as long as mesotarsomere I+II; metacoxae smooth, microreticulation exceptionally weakly impressed, composed of short, irregular cells, punctation nearly imperceptible, metacoxal lines distinct, broadly divergent anteriorly; hind legs slender, smooth, metafemur with fine weakly impressed reticulation composed of elongate cells, almost imperceptible weakly impressed punctation, setigerous punctures on anterior surface of metatibia and metatarsomere I, metatrochanter apically spinous, metatibial spurs slender, anterior spur shorter than metatarsus I, posterior spur as long as metatarsus I+II. Abdominal ventrites broad, smooth and unmodified, with fine weakly impressed reticulation, composed of irregular elongate cells, punctation nearly imperceptible.

Male genitalia ( Fig. 11 ). Median lobe broad, in left lateral view weakly curved, apex expanded, dorsal surface weakly sinuate, apex broadly rounded, covered in pores in apical 2/3; ventral groove in right lateral view strongly narrowed at half length, abruptly widened in apical 1/4.

Sexual dimorphism. Only one female was available for study, which was similar in size to the other males.

Variation. Only six specimens were available for study, all were similarly sized.

Differential diagnosis. Platynectes garciai sp. nov. is most similar to P. tafelbergensis sp. nov. in elytral maculation, having a very subdued maculation pattern with less than five yellow spots on each elytron, but differs in being larger (body length = 6.6–6.7 mm), more evenly rounded, and having distinct parascutellar maculae ( Fig. 6 ). Having distinct parascutellar maculae with up to three other subdued yellow spots should generally prevent its confusion with any other species within the P. submaculatus -group.

Etymology. The specific epithet honors our aquatic beetle worker and Venezuelan colleague Mauricio García for his passionate work to better understand the aquatic beetle fauna of Venezuela.

Natural history. All collecting events for this species were stream-associated, either along the margins of small streams among detritus, or in small detrital pools alongside small creeks ( Fig. 16 ).

Distribution. This new species is known from the Gran Sabana region of southeastern Venezuela and from Kaieteur National Park in central Guyana ( Fig. 15 ).

Figures

Figs 1–6. Dorsal habitus of Platynectes species. 1 – P. meru sp. nov. 2 – P. decemnotatus (Aubé, 1838). 3 – P. elaskanaima sp. nov. 4 – P. tafelbergensis sp. nov. 5 – P. submaculatus (Laporte, 1835). 6 – P. garciai sp. nov. Scale bar = 2 mm.

Figs 7–13. Median lobe of aedeagus of Platynectes species, top row left lateral view, bottom row right lateral view. 7 – P. submaculatus (Laporte, 1835). 8 – P. elaskanaima sp. nov. 9 – P. meru sp. nov. 10 – P. decemnotatus (Aubé, 1838). 11 – P. garciai sp. nov. 12 – P. tafelbergensis sp. nov. 13 – P. agallithoplotes sp. nov.

Fig. 15. Distribution map of Platynectes species of northern South America.

Figs 16–19. Habitat of Platynectes species. 1 – Collecting Event AS-08-060b, Venezuela, Bolivar State: Rio Aponwao (P. garciai). 2 – Collecting Event SR10-0829-01A, Suriname, Sipaliwini District, along Sipaliwini River (P. decemnotatus). 3 – Collecting Event SR13-0819-05B, Suriname, Sipaliwini District, Tafelberg Tepui summit (P. decemnotatus, P. tafelbergensis). 4 – Collecting Event SR13-0819-02A, Suriname, Sipaliwini District, Tafelberg Tepui summit (P. tafelbergensis).