Mucomyia emersa Kvifte and Curler, 2018

Kvifte, Gunnar Mikalsen, Curler, Gregory R. & Marshall, Stephen A., 2018, Aquatic insects in the forest canopy: a new genus of moth flies (Diptera: Psychodidae) developing in slime on aerial roots, Journal of Natural History 52 (3 - 4), pp. 137-153 : 140-146

Mucomyia emersa Kvifte and Curler , sp. nov.

( Figures 1–6 )

Type material

Holotype male. COSTA RICA, Heredia Province: Braulio Carrillo National Park, Quebrada Gonzalez loop trail, ( WGS84 ) 10°9ʹ39.23ʺN 83°56ʹ18.41ʺW, 527 m, 15.viii.2013, leg. S.A. Marshall; deposited in MRCA. Specimen dissected, mounted on micro-slide.

Other material

Same data as holotype, 1 instar IV larval exuvia, 1 pupal exuvia (mounted in Canada Balsam on one slide); deposited in LACM .

Diagnosis

Frontal scar patch without dorsal extension leading to eyebridge. Parabasal processes parallel to upper margins of parameres, lateral base less than twice as broad as (medial) apex. Parameres not distinctly hooked apicolaterally. Aedeagus with two distal phallomeres of slightly different length. Surstylus with single apical tenaculum.

Description

Adult male (n = 1). Head ( Figure 5 (a)) broadly oval; vertex a third of head length, hind margin of head nearly straight except median thoracic joint; eyebridge of four facet rows, separated by 1.5 facet diameters; interocular suture broadly V-shaped; more than 20 supraocular setae present, reaching stems of interocular suture, uniseriate dorsal to eyebridges, biseriate dorsal to eye, triseriate laterally; frontal scar patch broadly oval with median posterior extension reaching level of anterior margin of eyebridge; clypeus trapezoid, anterior margin about half as broad as posterior margin, sides tapering evenly; frontoclypeal suture complete, broadly U-shaped; labrum, maxillae and labium as long and wide as anterior width of clypeus; labellae fleshy, lateral margins more strongly sclerotized, with six dorsolateral and three ventral setae; palp of four segments, cylindrical except fourth segment spool-shaped; fourth palp segment fully sclerotized; length of palp segments 50:60:70:70; antennae incomplete in type specimen, with only scape, pedicel and first five flagellomeres preserved; scape cylindrical, pedicel globular, flagellomeres nodiform symmetrical; ascoid attachments paired, present on all flagellomeres; flanked by smaller circular or spiniform sensilla (hard to ascertain in specimen); length of scape, pedicel and first five flagellomeres 70:55:100:90:90:90:85; ascoids Y-shaped; thorax ( Figure 3 ) with dorsum, anepisternum, laterotergite, scutellum and ventral half of katepisternum setose; postpronotal lobe, anepimeron, katepisternum and meron naked; prothoracal spiracle naked, metathoracic spiracle densely setose; coxae all with dorsoventral anterior aseriate rows of setae, densest at ventral half of mid coxa; pointed extensions present on anterior side of front tibia and posterior end of mid and hind tibiae; tarsomere 5 without dorsal extension; wing ( Figure 3 ) 1.4 mm long, not fully sclerotized in type specimen, veins generally hard to discern; C with two breaks, Sc terminating in wing membrane but approaching R 1, reaching halfway between base of M 1+2 and R 5; wing membrane setose; R 5 terminating in wing apex; radial fork distal to medial fork, complete; medial fork hard to discern; jugum broadly angulate oval, setose; narrow oval patch of setae present dorsal to jugum; male genitalia ( Figure 5 (b)) with hypandrium membranous, curved concavely at median, reaching tips of gonocoxites; gonocoxites reniform-cylindrical, 1.3 × length of gonostyles; gonostyles conical with blunt apices, with scattered sensilla; aedeagus with basiphallus narrow at base, distally with median keel; distiphallus apparently spatulate with two phallomeres originating from lateral margins of apex of basiphallus; phallomeres narrow, pointed apically, left phallomere slightly longer than right; gonocoxal condyles wing-shaped, flat, approaching medially but not touching, with margin strip-like, thicker and more strongly sclerotized than rest of condyle; subtriangular parameres present, presumably originating from sclerotized posterior margin of gonocoxite, hooked at medial basal end at junction with subepandrial membrane, distally hooked towards the lateral; parameres as long as gonocoxite; epandrium ( Figure 5 (b)) broader than long; base with strip-like apodeme, concave without laterobasal projections; single oval aperture present at median; fleshy setose projections present laterally on distal third; hypoproct oval with slightly pointed lateral edges, fused with subepandrial membrane; subepandrial membrane triangular, tapering towards base; epiproct (not illustrated) present as strip-like sclerite on ventral distal edge of hypoproct; surstyli cigar-shaped, about as long as epandrium; with single distal tenaculum; tenaculum spatulate with longitudinal striations, apex slightly pointed but without fringes.

Pupa ( Figures 4 (c), 4(d) and 6(e–h)). Cuticle glabrous, without pigment. Respiratory organ digitiform; apical 1/3 of respiratory organ curved anteriorly, with paired, longitudinal row of pores dorsally, with two pores at mid-length of organ, at apices of bumps. Mesonotum with conspicuous transverse bands of microtrichia inserted anteriorly, dorsally. Abdominal segments 1–8 with fringe of prominent microtrichia along posterior margins; segment 9 with four protuberances lateroventrally on each side; lateroventral protuberances each with a seta inserted apically; hook-shaped protuberances posterodorsally, conical protuberances posteroventrally; posteroventral protuberances each with a prominent seta inserted apically; genital lobes each with a spiniform protuberance flanked by setae apically.

4th instar larva ( Figures 4 (a), 4(b) and 6(a–d)). Head capsule ovate, brown; antenna composed of single prominent mushroom element, one digitiform, six globular

sensilla basiconica, two sensilla trichodea; labrum covered with simple microtrichia ventrally, with one sensilla basiconica inserted anteriorly on each side; maxillary palp cylindrical, rounded apically, with single seta inserted at apex; lacinia composed of spiniform and setiform microtrichia; mandibles each with five dentations apically; prostheca composed of one brush-like seta and one simple seta; postmentum truncate, without teeth. Anterior spiracles digitiform, inserted laterally on posterior annulus of prothorax. Trunk: cylindrical; integument pale, except brown tergal plates; segmentation typical of Psychodinae : pro, meso and mesothorax, abdominal segment 1 with two annuli, abdominal segments 2–7 each with three annuli; hirsute, covered with inconspicuous microtrichia; microtrichia more numerous, entangled laterally, ventrally; tergal plates quadrangular, each with multiple, irregular, transverse rows of microtrichia; microtrichia along posterior margins of tergites more prominent; protergites without setae, mesotergites with transverse row of four setae, metatergites with two setae dorsally, flanked by paired setae dorsolaterally; mesosternum of segments 1 and 2 with transverse, clustered rows of prominent microtrichia along anterior and posterior margins; mesosternum of segments 3–7 with transverse bands of less prominent microtrichia, not arranged in rows; anal division with dorsal and ventral sclerites fused laterally, encircling anal division basally, conical apically, with inconspicuous microtrichia distributed evenly on surface; flabellar processes not elongate, approximately 1/8 the length of anal division, with fringe of spathiform setae; length of ventral flabellar processes approximately two times that of dorsal processes.

Distribution

Known only from the type locality in Braulio Carillo National Park , Costa Rica .

Biology

Mucomyia larvae were observed moving freely within the mucilaginous matrix on root tendrils hanging at c. 150–200 cm above ground. The same mucilaginous masses also held several dead thrips (Thysanoptera) and some unidentifiable remains of other insects, suggesting that this sticky, viscous material is only hospitable for some insects. Larvae did not make contact with either the root tissue or the embedded, dead insects and during the short (less than one hour) period of observation prior to collection, no obvious feeding behaviour was observed.

The plant from which this species was collected could not be identified beyond family ( Araceae ). In order to identify it to genus and perhaps species, flowers must be examined; unfortunately, the plant encountered in this study was not flowering. Multiple genera of Araceae are known to have mucilage covering their hanging roots (Paul Hanson, pers. comm.)

Etymology

Past tense of Latin emertare, ‘emerge’, referring to the type material being a reared specimen. The epithet is to be treated as a participle and thus follows the grammatical gender of the genus.

Figures

Figure 1. Araceae plant from which Mucomyia emersa larvae were collected. (a) Habitus of plant, (b) detail of plant mucilage inhabited by larvae.

Figure 2. Habitus of Mucomyia emersa larvae in plant mucilage.

Figure 3. Habitus of Mucomyia emersa male, head and abdomen removed.

Figure 4. Mucomyia emersa immature stages. (a) Larval head capsule, ventral view; (b) larval mouthparts, ventral view; (c) segment IX of pupa, dorsal view; (d) segment IX of pupa, ventral view. Scale bars = 0.1 mm. Abbreviations: lm = labium; lr = labrum; mc = maxillary cardo; md = mandible; mp = maxillary palp.

Figure 5. Mucomyia emersa adult male. (a) Male head, frontal view, (b) male terminalia, dorsal view. Scale bars = 0.1 mm. Abbreviations: ae = aedeagus; ea = ejaculatory apodeme; ep = epandrium; gc = gonocoxal condyle; gs = gonostyle; gx = gonocoxite; ha = hypandrium; ho = hypoproct; pm = paramere; ss = surstylus; tn = tenaculum.

Figure 6. Scanning electron micrographs of larval and pupal Mucomyia emersa. (a) Antenna of larva, dorsal view; (b) anal division of larva, dorsal view; (c) segment VII of larva, dorsolateral view; (d) detail of posterior spiracles of larva, dorsal view; (e) respiratory organ of pupa, anterodorsal view; (f) mesonotum of pupa, anterodorsal view; (g) partial thorax and abdomen of pupa, anterodorsal view; (h) segment IX of pupa, dorsal view. Scale bars = 10 µm (a–f), 100 µm (g, h). Abbreviations: m = mesotergite; me = mushroom element; mt = microtrichia; p = protergite; pr = pores; ps = posterior spiracles; st = setae; t = metatergite.