Yara maculata Short, Joly, and García, 2010

Short, Andrew E. Z., Joly, Luis J. & García, Mauricio, 2010, Discovery of the Skiff Beetle GenusYaraReichardt and Hinton (Coleoptera: Myxophaga: Hydroscaphidae) in Venezuela, with Description of a New Species, The Coleopterists Bulletin 64 (2), pp. 151-156 : 152-154

Yara maculata Short, Joly, and García , new species

Type Material. Holotype (♂): “ VENEZUELA: Amazonas State / 5°48.414′N, 67°26.313′W, 80m / nr. Iboruwa: “Tobogancito”/ 13.i.2009; leg. A. Short; shallow/ backwater of streamlet over/ bare rock; VZ09-0113-02A”. Deposited in the Museo del Instituto de Zoología Agrícola ( MIZA), Universidad Central de Venezuela (Maracay, Venezuela) . Paratypes (483): Venezuela: Amazonas: Same data as holotype (336 exs.) ; same data except: river

margin, VZ09-0113-02C (10 exs.); Tobogán de la Selva, 5°23.207′N, 67° 36.922′W, 125 m, 14.i.2009, L. J. Joly, M. García, side seepage, VZ-09-0114-01B (2 ♂♂); Canturama, S. Puerto Ayacucho, 5°30.623′N, 67°36.109′W, 15.ix.2007, M. García, L. J. Joly, A Short (1 ♂); River nr. confluence of Orinoco and Sipapo Rivers, 5°03.707′N, 67°46.768′W, 92m, 15.i.2009, leg. A. Short, shallow backwaters, VZ09-0115-01C (130 exs.). Bolívar: ca. 25 km E. El Burro, 6°13′4.6″N, 67°14′26.4″W, 60m, 7.viii.2008, leg. L.J. Joly, rocky morichal, AS-08-077 (3 ♂♂, 1 ♀). In addition to MIZA, paratypes will be distributed in the following institutions: Division of Entomology , University of Kansas (Lawrence, KS, USA) , Museo de Artrópodos , Universidad del Zulia (Maracaibo, Venezuela), United States National Museum of Natural History (Washington, DC, USA) , Vienna Natural History Museum (Vienna, Austria) , Czech National Museum (Prague, Czech Republic) , the Field Museum of Natural History (Chicago, IL, USA) and Museu de Zoologia da Universidade de São Paulo (São Paulo, Brazil) .

Description. Total body length 1.50–1.75 mm. Body fusiform, very elongate. Color: Clypeus and central third of frons and central third to half of pronotum brown, with remaining regions of head

(elytra removed), C) Male sternites VIII and IX.

and pronotum yellow. Elytra brown with yellow spots. Abdominal tergites III-VII light brown, with segments sometimes margined in yellow; tergite VIII dark brown in apical two-thirds, with basal third yellow.

Head. Dorsal surface distinctly microreticulate. Eyes not bulging or protruding, in same plane as dorsal surface of head, and forming continuous, unbroken outline laterally ( Fig. 2 ). Antennal scape elongate, about as long as pedicel and antennomere III combined; antennomeres III-VIII short and similar in size; segment VIII elongate, slightly asymmetrical, as long as antennomeres III-VII combined. Frontoclypeal suture present. Maxillary palp 4-segmented; palpomere III greatly swollen, with apical palpomere small and partly recessed into apex of previous palpomere.

Thorax. Dorsum of elytra covered with moderately long setae; base of each seta set in arched groove, such that surface appears to have rough sculpturing ( Fig. 3 ). Lateral margin of elytra slightly attenuated in posterior half; mesad apex evenly rounded, without tooth or projection. Metathoracic wings well developed, with marginal fringe (condition of wings examined in approximately 50 specimens, including both males and females). Metacoxae with ventral plate-like extension restricted to mesal half, only covering extreme base of femur. Trochanter with 6 sharp, thickened, spinelike setae along lateral margin ( Fig. 4A ).

Abdomen. Tergite IV not materially differentiated from remaining abdominal segments; without dense patch of setae; set with few thickened setae anteriorly ( Fig. 4B ). Tergite VIII of males slightly tapered to blunt, flat distal margin; tergite VIII of females narrowly tapered, with small shallow emargination at apex. Sternite VIII of males with deep, asymmetrical notch apically; left side of notch set with row of 4, thickened curved setae ( Fig. 4C ). Females with segment IX apparently absent or reduced, such that segment VIII appears as last visible segment ( Fig. 5A ). Males with segment IX well developed and exposed, such that it appears as last visible segment; tapered to acute point in apical third ( Fig 5B ). Aedeagus with short forked base articulated to basal bulb of long, filamentous median lobe ( Fig. 6).

Etymology. The name is a Latin participle and adopted for the yellow patterning on the dorsum.

Biology. The vast majority of specimens were collected at a few collecting events in the early dry season (January) in streams flowing over solid granite ( Fig. 7 ). During these collecting events, large numbers of specimens were collected in shallow (<5 cm) marginal areas that were connected to the stream but represented side pools, and not actively flowing. Algae were growing on the rock substrate. Specimens were not collected in nearby rock seepages or by scrubbing the rock substrate in the stream flow, suggesting the species occupies a very narrow habitat along the slack margins of streams with rock substrate. While slightly fewer than 500 specimens were mounted, the species was present in the thousands at the type collecting event.

Figures

Fig. 2. Head of Yara maculata, A) Dorsal view, B) Ventral view, C) Frontal view, D) Front of head showing clypeus and frontoclypeal suture.

Fig. 3. Elytra of Yara maculata, A) Dorsal view, B) Ventral view.

Fig. 4. Thorax and abdomen of Yara maculata, A) Meso- and metathorax, ventral view, B) Tergites III and IV

Fig. 5. Abdomen of Yara maculata, dorsal view, A) Female, B) Male.

Fig. 7. Habitat of Yara maculata in Amazonas, Venezuela, A–B) Type locality and habitat, C) Adult beetles crawling on fine micron netting during collecting event VZ09-0113-02A, D) Second locality where adults were collected in moderate abundance, VZ09-0115-01A.