Desmopachria signatoides Miller, 2000

Miller, Kelly B., 2001, Descriptions Of New Species Of Desmopachria Babington (Coleoptera: Dytiscidae: Hydroporinae: Hyphydrini) With A Reassessment Of The Subgenera And Species Groups And A Synopsis Of The Species, The Coleopterists Bulletin 55 (2), pp. 219-240 : 225-226

Desmopachria signatoides Miller , new species

Figs. 8–10, 14

Diagnosis. Distinguishable from other members of D. convexa group by shape of male genitalia ( Figs. 8–10 ); median lobe in dorsal aspect elongate, narrow, apically deeply bifid and with rami slender and apically pointed ( Fig. 8 ); articulable spur of lateral lobe short and lateral lobe broad apically in dorsal aspect ( Figs. 8, 10 ).

Description. Measurements. n = 1, TL = 1.29 mm; GW = 0.88 mm; TL/ GW = 1.46.

Habitus. Small; broadly rounded laterally in dorsal aspect, posteriorly round­ ed; dorsoventrally slightly flattened; brown with indistinct yellow maculae.

Coloration. Head and pronotum yellow. Elytron brown with irregular yellow maculae anteriorly and with elytral apex yellow. Antennae and palpi yellow. Pro­ and mesothoracic legs yellow; metathoracic legs brown. Prosternum black; other thoracic and abdominal sterna yellow.

Sculpture and structure. Head very finely and sparsely punctate, but punctures distinct; anterior clypeal margin produced anteriorly and distinctly bead­ ed; antennae short, antennomeres 6–10 short, cylindrical, together very compact ( Fig. 14 ). Pronotum impunctate medially, indistinctly punctate laterally and along basal margin; lateral margin moderately rounded; lateral bead very narrow, slightly widened anteriorly. Elytron with punctures very fine and sparse, but distinct; epipleuron narrow, impunctate. Prosternum narrow, transversely strongly carinate and produced anteriorly, medial tubercle absent; prosternal process broad, apically broadly acuminate, surface slightly convex. Metasternum impunctate. Metacoxa very finely punctate, punctures inconspicuous. Abdominal sterna impunctate; sternum six with apicomedial tumidity, apex margined and with medial furrow extending from tumidity to apex.

Male genitalia ( Figs. 8–10 ). Median lobe in ventral aspect anteriorly broad and widely bifurcate, posteriorly with elongate, narrow section, with lateral margins slightly divergent with deep apical emargination making apex strongly bifid ( Fig. 8 ); in lateral aspect with medial broad area, apical portion elongatecurved with apex narrowly rounded ( Fig. 9 ). Lateral lobe in ventral aspect moderately broad, divided into two sections, apical section apically broad with laterally acutely pointed apex, with small region of setae subapically, posteriorly with distinct articulable lobe or spur; in lateral aspect with anterior portion very broad and robust, apical portion narrow with articulable lobe distinctly visible medially ( Fig. 10 ).

Female. Unknown.

Taxonomy. This species is a member of the D. convexa group (see Discussion below for clarification of group classification) based on the presence of an articulable spur on the lateral lobe, though it differs from all other species except D. signata Zimmermann in the shape of the male genitalia and the presence of elytral maculae. The species appears to be closely related to D. signata since both have maculate elytra and a bifid median lobe. However, the median lobe appears to be considerably longer and differently shaped in D. signatoides (see Figs. 8–10 , 32 ).

Etymology. This species is named signatoides for its similarity to the species D. signata in shape of male genitalia and elytral maculation.

Natural History. The single specimen of this species was collected from an artificial cattle watering pond in a relatively dry area of the Bolivian lowlands.

Material Examined. Holotype: ϐ in MHNB, labeled, ‘‘ϐ/ BOLIVIA: Dpto. Sta Cruz. Prov. Chiquitos 2.2km E San Jose. artificial cattle pond 26 June 1999 KB Miller, colr./ 17°51'00̎ S 60°43'02 ̎W 315m #2–12 / HOLOTYPE Desmopachria signatoides K.B. Miller, 2000 [red label with double black line border].’’ This species is known only from the holotype.

Figures

Figs. 2–14. Desmopachria spp., male genitalia. 2–4) D. amyae; 2) median lobe and left lateral lobe, dorsal aspect; 3) same, median lobe, right lateral aspect; 4) same, right lateral lobe, right lateral aspect; 5–7) D. challeti; 5) median lobe and left lateral lobe, dorsal aspect; 6) same, median lobe, right lateral aspect; 7) same, left lateral lobe, left lateral aspect; 8–10) D. signatoides; 8) median lobe and left lateral lobe, dorsal aspect; 9) same, median lobe, right lateral aspect; 10) same, right lateral lobe, right lateral aspect; 11–13) D. volatidisca; 11) median lobe, dorsal aspect; 12) same, median lobe, right lateral aspect; 13) same, right lateral lobe, right lateral aspect; 14) Desmopachria signatoides, left antenna, dorsal aspect. bars = 0.1 mm

Figs. 21–33. Desmopachria convexa group, male genitalia. 21) D. aspera; 22) D. cenchramis; 23) D. circularis; 24) D. convexa; 25) D. defloccata; 26) D. glabella; 27) D. grana; 28) D. isthmia; 29) D. laesslei; 30) D. lewisi; 31) D. majuscula, median and lateral lobes; 32) D. signata, median and lateral lobes; 33) D. tarda. a = median and lateral lobes, b = lateral lobe.