Dorytocus ornithorhynchus Emeljanov et Shcherbakov, 2018

Emeljanov, A. F. & Shcherbakov, D. E., 2018, The longest-nosed Mesozoic Fulgoroidea (Homoptera): a new family from mid-Cretaceous Burmese amber, Far Eastern Entomologist 354, pp. 1-14 : 4-10

Dorytocus ornithorhynchus Emeljanov et Shcherbakov , sp. n.

Figs 1–22

MATERIAL. Holotype PIN 5608 /3, nymph of supposed instar V (right hind leg broken off distal to mid-tibia); paratypes PIN, nymphs: 5608/4, supposed instar III

(translucent, eyes transparent, but not exuvium; abdomen telescoped and upcurved,

tergite I hidden under metanotum, apex of abdomen polished away; right side adjacent to a level of debris; gas bubbles on left side), likely sucked out by a spider or predatory bug; 5608/5, supposed instar II — Burmese amber, Hukawng Valley,

Kachin State, Myanmar; mid-Cretaceous, Albian–Cenomanian.

– ventral view; 3 – head, ventrolateral view; 4 – end of abdomen and distal part of hind leg,

dorsal view; 5 – distal part of hind leg, ventral view; 6 – fore and mid leg; 7 – hind tarsus,

laterodorsal view. Scale bars, 1 mm (1–3), 0.5 mm (4–6), and 0.2 mm (7).

DESCRIPTION. Nymphs. Rather slender, resembling long-headed Dictyopharinae such as Dictyophara (Chanithus) pannonicа (Germar, 1830) , Scolops Schaum,

1850 etc.

All nymphal instars (based on supposed V, III and II instar). Head produced into anteriorly directed process (degree of elongation, shape of head process and some other characters change with instar – see below). Coryphe arrowhead shaped, basally triangular, distally tapered up to narrow stripe separating lateral areas of head process (halves of acrometope) that are faced laterodorsally and nearly meet along midline. Lateral area at base separated from preocular area by carina. Coryphe depressed towards median line, V-shaped in cross-section, with vestigial Y- or T-

shaped carina in basal part. Carina between eumetope and lateral areas forming apical callus at head apex. Eumetope parabolic rounded at apex, widest anterior to

9 – ventral view; 10 – head and prothorax, lateral view; 11 – distal part of hind leg, dorsolateral view; 12 – mid and hind tarsus. Scale bars, 1 mm (8–10) and 0.2 mm (11–12).

eye, with simple median carina, without intermediate carinae (represented only by lateral areas with sensory pits). Eumetope in profile shallowly concave anterior to eyes and convex distally, in cross-section tectiform, especially towards apex; head process distally diamond-shaped in cross-section. Boundary of eumetope and postclypeus (epistomal suture) nearly straight. Postclypeus with carinae as sharp as on eumetope, slightly tapered apically, about twice as long as wide. Anteclypeus elongate, about as long as postclypeus. Rostrum long, slender, dark and acuminate at apex, reaching at least abdominal segment VII; apex of middle segment far beyond mid coxae. Eys not much projecting laterally, mostly concealed by pronotum from above. Antennae small; pedicel twice longer than scape.

view; 14 – ventral view; 15 – lateral view; 16 – end of abdomen, dorsal view; 17 – end of abdomen and hind tarsi, ventral view. Scale bars, 1 mm (13–15) and 0.2 mm (16–17).

Pronotum inverted V-shaped in dorsal view. Disc of pronotum produced forwards up to level much anterior to eyes, forming angulate pronotal ledge to conceal posterior margin of coryphe. Pronotum bounded anteriorly with jugal carina. [In nymphs, this

“primary carina of pronotal dorsum” was termed either lateral (Yang & Yeh, 1994)

or jugal (Emeljanov, 2001). The former term is inappropriate, because this carina is rather oblique-transverse, not developed as a whole in adults, and does not fit into accepted nomenclature of adult pronotal carinae, including the version proposed and corrected by Emeljanov (1980, 1996). In nymphs of many families, the jugal carina is developed as integral carina uniting the anterior carina of disc, postocular carina, and main portion of the adult lateral carina.] Lateral margin of pronotal dorsum sinuate above eye. Posterior angles of pronotum reaching beyond midlength of mesonotal disc. Posterior margin of pronotum deeply angulately incised, incision reaching level of anterior orbitae or nearly so and occupying more than half of pronotal length.

Median carina of pronotum double. Pronotal paranota more or less rhomboidal,

with horizontal and vertical carinae, the latter joining lower margin before posterior angle of pronotum. Disc of mesonotum for most of its length embraced between paradiscal parts of pronotum; median and lateral carinae of mesonotal disc sharp;

lateral carinae of the disc running along margins of pronotal incision, continuing their direction caudally, and continued with inner margins of forewing pads; posterior margin of mesonotal disc transverse, wavy. Metanotum sinuate posteriorly, with sharp median carina.

Legs rather slender. Fore and mid tibiae flattened, with foliaceous dorsal (outer)

and ventral (inner) edges. Hind tibiae thin, terete, without lateral teeth; apical pecten asetigerous, i.e. without subapical setae on dorsal sides of apical teeth, but with long setae on plantar surface. Fore and mid tarsi 2-segmented, with 2nd tarsomere twice longer than 1st. Hind tarsus 3-segmented (instar V) or 2-segmented, in instar

III with lateral teeth on apical tarsomere. Pretarsus with powerful, curved claws and relatively narrow, pear-shaped arolium.

Abdomen from segment IV gradually tapered posteriorly. Very short tergite I and shortened tergite II not reaching lateral margins of abdomen; slightly elongated tergite III longer than each of subequal tergites IV–VI; elongate tergites IX and X

not retracted between lateral lobes of tergite VIII. Tergites II–X with sharp median and intermediate carinae; tergites III–X with lateral carinae, on III–IX foliaceous.

Laterotergites faced ventrally. Segment IX longer than VIII or X. Segment X longer than wide, at apex with long tongue-like dorsal sclerite (epiproct) and subtriangular lateral sclerites (paraprocts), sometimes (instar II paratype) with everted rectum .

Sensory pits (based mainly on the paratypes, III and II instar; less well preserved pits in the holotype instar V conform the pattern; the description is given for one side only). Eumetope at each side with 2 longitudinal rows, lateral and median; pits of lateral row smaller than those of inner row and generally alternating with them ;

between eyes additional intermediate row of minute pits; few minute extraserial pits.

Pronotum dorsally with 2 somewhat irregular, oblique longitudinal rows of pits varying in size, 12 pits in posterior (inner) row, 8 in anterior (outer) row; 4 poste-

riormost pits without counterparts in anterior row; several minute extraserial pits anteriorly and posteriorly. Disc of mesonotum with two pit rows medial to laterodiscal carina (5 pits along carina and 5 medial to former row); paradiscal area with 2–4 pits; forewing pad with 4 pits. Metanotum with group of 5 pits (3 small in anterior row and 2 large posteriorly) in discal area and 2–3 pits on hind wing pad.

Abdominal tergites III–VIII with 1 minute medial pit, 1 small intermediate pit, and 2

or 1 lateral pits (smaller outer pit absent on tergite III and sometimes on tergite IV);

tergite IX with 3 pits and 1 small pit anterior to inner pit.

Lateral carinae of postclypeus, carinae of coxae, femora, tibiae and tarsi, and lateral carinae of abdomen with long hairs.

Nymphal instars differ in proportions, head shape, degree of tibia flattening, hind leg armature, number of tarsomeres etc. Each next instar is ca. 1.4 times longer than the preceding one, which is consistent with the assumption that all the studied instars are conspecific.

dorsal view; 19–20 – paratype instar III nymph: 19 – body, dorsal view; 20 – head and pronotum, lateral view; 21–22 – paratype instar II nymph: 21 – body, dorsal view; 22 – head ,

pro- and mesonotum, ventral view. Scale bars, 1 mm.

Instar V. Head process nearly straight and parallel-sided, very narrow, x6.5 as long as wide, 1/4 of body length and 0.85 of thorax length. Eumetope without pale oval area, in apical 1/4 darker and without discernible pits except near apex. Thorax

x1.9 as wide as head. Fore- and hind wing pads acuminate, almost reaching posterior margin of abdominal tergite III; metanotum without laterodiscal carinae. Fore and mid tibia foliaceous (thrice as wide as middle part of hind tibia), fore lanceolate,

mid nearly so, dorsal edge with long, ventral edge with long and distally with shorter, stronger setae, 3–4 of which grouped comb-like at apex anteroventrally.

Hind tibial pecten of 6 asetigerous teeth, 3 in medial and 3 in lateral group. Hind tarsus 3-segmented; 1st tarsal pecten of 8 setigerous teeth, 2nd of 6 setigerous teeth.

Claws with 3 setae in basal third. Abdomen widest at segment III. Bilobed genital rudiment beyond posterior margin of sternite VIII. Segment IX about as long as wide, much longer than VIII, slightly tapered distally. Segment X slightly longer than wide, as long as VIII, twice narrower than IX. Cuticle dark, mottled with pale.

Body 10.5 mm long.

Instars II–III. Coryphe in profile straight basally and convex distally. Eumetope before head apex with pale oval area devoid of sensory pits; pits near head apex smaller and denser. Cuticle pale with dark markings, including dark streaks on thoracic nota, abdominal tergites, and flattened tibiae. Dorsum with fine cover of microscopic wax particles.

Instar III. Head process widest about midlength, slightly constricted near base,

rather narrow, x2.5 as long as wide, about 1/5 of body length and 0.6 of thorax length. Thorax x1.6 as wide as head. Forewing pads reaching midlength of metanotum, hind wing pads poorly projecting backwards; metanotum without laterodiscal carinae. Fore and mid tibiae as in instar V — foliaceous (thrice as wide as middle part of hind tibia), lanceolate, with short setae grouped comb-like at apex. Hind tibial pecten of 6 asetigerous teeth: 3 long inner, 1 long outer, and 2 shorter in between. Hind tarsus 2-segmented. 1st tarsal pecten of 6 teeth, with narrow diastema,

teeth (possibly except for outermost) with long subapical seta. 2nd tarsomere about midlength with a pair of teeth at sides, inner (posterior) tooth double. [Taking into account the presence of subapical setae, this pattern corresponds to instar III in the tribe Ranissini ( Dictyopharidae Orgeriinae); all the same in Dictyopharinae , but their nymphs have no subapical setae (Emeljanov, 1995, 2001).] Claws with 1 seta in basal third. Abdomen widest at segment III. Body 4.2 mm long as preserved;

reconstructed body length (based on head+thorax length) ca. 5.3 mm.

Instar II. Head process widest at base, tapered towards apex, short, x1.4 as long as wide, 1/8 of body length and 0.37 of thorax length. Thorax x1.4 as wide as head.

Forewing pads not reaching midlength of metanotum, hind wing pads poorly projecting backwards; metanotum with faint laterodiscal carinae. Fore and mid tibiae less flattened than in instar III (twice as wide as middle part of hind tibia). Hind tibial pecten of 6 asetigerous teeth. Hind tarsus two-segmented; 1st tarsomere large,

wider and longer than 2nd, with pecten of 6 setigerous teeth (setae not visible on two inner teeth); apical tarsomere terete, without lateral teeth marking apex of future middle tarsomere. Claws without setae, less curved than in instar III. Abdomen widest at segment IV. Body 3.8 mm long.

REMARKS. From one of amber dealers, several photographs of an adult were obtained, probably the same species. Habitually somewhat similar to leafhoppers

Adelungia Melichar, 1902 ( Cicadellidae Adelungiinae). Head process very long,

constituting more than 1/3 of the body length (with wings), ensiform, acuminate,

deflected dorsally. Pronotum inverted V-shaped, with deep triangular incision posteriorly. Tegmina leathery, as long as the head process, not much projecting beyond the apex of abdomen; (SC+)R forked basally, CuA forked before wing midlength, M much later. Legs slender. Body mottled with dark. About 20 mm long.

ETYMOLOGY. From the Greek ornis (bird) and rhynchos (snout); alluding to the head process as in the duckbill).

Figures

Figs 1–7. Dorytocus ornithorhynchus sp. n., holotype instar V nymph: 1 – dorsal view; 2

Figs 8–12. Dorytocus ornithorhynchus sp. n., paratype instar III nymph: 8 – dorsal view;

Figs 13–17. Dorytocus ornithorhynchus sp. n., paratype instar II nymph: 13 – dorsal

Figs 18–22. Dorytocus ornithorhynchus sp. n.: 18 – holotype instar V nymph, body,