Moiradiomus clotho, Vandenberg & Hanson, 2019

Vandenberg, Natalia J. & Hanson, Paul E., 2019, Overview of the lady beetle tribe Diomini (Coleoptera: Coccinellidae) and description of a new phytophagous, silk-spinning genus from Costa Rica that induces food bodies on leaves of Piper (Piperaceae), Zootaxa 4554 (1), pp. 255-285 : 272-273

Moiradiomus clotho sp. nov.

( Figs. 13, 14 , 25 , 29 )

Diagnosis. Most readily distinguished from its congeners by the male genitalia ( Fig. 29 ) with basal lobe terminating in a hook-shaped process ( Fig. 29d ) resembling a vulture’s head, and parameres relatively slender, weakly expanded distally, with longest setae subequal in length to paramere. The adult can be distinguished by the elongated terminal maxillary palpomere ( Fig. 13, 14 ). It differs from M. lachesis in possessing a larger head and eyes, and narrower frons. It is also distinguished by its larval host plant: P. holdridgeianum W. C. Burger, 1971 .

Description of holotype (male) ( Fig. 13 ). Length 1.9 mm, width 1.0 mm. Form elongate, oval, weakly convex. Metathoracic wing present. Dorsal surfaces feebly shining, distinctly punctate, pubescent with fimbriate borders. Head, pronotum, appendages including mouthparts, straw yellow, with meso- metacoxae slightly darkened; head slightly darker and oranger than pronotum; scutellar shield medium brown; elytron medium brown with apex narrowly yellow, epipleuron yellow brown; pubescence shiny, off white. Venter predominantly brown, darkest on meso-, metaventrite; prosternum pale yellow; mesepimeron paler than surrounding sclerites with margins narrowly darkened; abdomen pale brown, lighter, yellower toward apex; tarsal claw, mandibular apex dark reddish amber. Dorsal punctation moderately coarse; punctures separated by approximately 1× diameter, on elytron equal in width to eye facet, finer on head, pronotum. Dorsal pubescence semi erect, moderately dense, evenly distributed, lacking distinct setal pattern; individual setae equal to about 2/3 to 1× length of scutellar shield, arcuate; elytral setae mostly directed posteriorly except directed outwardly at sides of body, posterolaterally near suture. Head large, 0.70× width of pronotum; eye large, finely facetted, with interfacetal setae, weakly notched near antennal insertion by small rounded ocular canthus; inner orbits arcuate, strongly diverging toward vertex, weakly diverging toward clypeus, with minimum separation at slightly below midlength; interocular distance 1.5× width of eye in frontal view. Antenna composed of 10 antennomeres; antennomere 3 elongate, about 2.3× length of antennomere 4; last 4 antennomeres forming gradual club expanding apically from antennomere 7–9; antennomere 10 subrhomboidal, slightly narrower, slightly longer than 9. Maxillary palp with terminal palpomere elongate, moderately expanded distally; with oblique apex. Pronotum transverse, width 2.0× length, weakly, evenly convex. Elytron in dorsal view with lateral margin weakly arcuate; elytral apices dehiscent. Ventral surfaces pubescent, distinctly punctate, except glabrous, impunctate in posterior 4/5ths of metacoxal plate; punctation coarser, denser on abdomen. Prosternum ( Fig. 25 ) with carinae of intercoxal process extending nearly to apex, weakly convergent, framing subtriangular depression with broadly rounded apex. Suture between abdominal ventrites 1 and 2 distinct, linear; 5 th, 6 th ventrite with apex shallowly, roundly emarginate in median ½. Tarsal claw with broad scythe-like inner tooth extending from base to apical 1/3 rd or beyond.

Male genitalia ( Fig. 29 ). Basal lobe in ventral view ( Fig. 29b ) subparallel in basal half, strongly tapered toward apex in distal half, terminating in small hook-shaped swelling resembling vulture's head ( Fig. 29d ), distinctly shorter than paramere; in lateral view weakly sinuous ( Fig. 29a ), with apex nearly flat; paramere elongate, gradually expanded, apically rounded, about 3.0× as long as wide, subequal in length to longest setae. Penis ( Fig. 29c ) lacking apical flagellum, slender with wedge-shaped capsule.

Female ( Fig. 14 ). Similar to male except slightly smaller on average with more extensive brown pigmentation; base of head orange brown; pronotum brown with anterolateral margins yellowish; posterolateral angle of hypomeron, submentum medium brown; prosternum dark brown. 5 th abdominal ventrite with posterior margin linear; 6 th ventrite with posterior margin arcuate. Tarsal claw with short triangular tooth near base, not extending beyond apical ½.

Variation. Length 1.5–2.0 mm. Individuals vary slightly in the extent and intensity of dark pigmentation on dorsal and ventral surfaces.

Trophic relations. Larvae develop on food bodies of P. holdridgeianum .

Etymology. Clotho, proper noun in apposition, Classical Latin from Greek κλΏΘΩ (klotho), to spin. In Greek mythology, the youngest of the three Fates or Moirae; the spinner of the thread of life.

Type material. Holotype (male) with labels: “ COSTA RICA: San José : Zurqui de Moravia, 1600m, II– III.2014, P. Hanson / ex. Piper holdridgeiana ” ( USNM) and 5 paratypes (2 males, 3 females) with same labels as holotype (2, USNM; 3 MZUCR).

Figures

FIGURES 13–16. Moiradiomus species habitus illustrations. 13, M. clotho: holotype, male; 14, M. clotho: paratype, female. 15, M. lachesis: holotype, male; 16, M. lachesis: paratype, female. Scale bar = 0.5 mm.

FIGURES 25–28. Diagrammatic ventral view of Moiradiomus prosterna (setae, color patterns, and surface punctation not indicated): 25, M. clotho; 26, M. lachesis; 27, M. atopos; 28, M. nanita.

FIGURES 29–32. Male genitalia of Moiradiomus species (a, left lateral view of phallobase; b, ventral view of phallobase; c, left lateral view of penis; d, apex of basal lobe, enlarged): 29, M. clotho; 30, M. lachesis; 31, M. atopos; 32, M. nanita.