Saturday, June 27, 2020

[Entomology • 2020] Ustyurtia zygophyllivora & U. charynica • Ustyurtiidae, A New Family of Urodoidea (Lepidoptera) with Description of A New Genus and Two Species from Kazakhstan, and Discussion on Possible Affinity of Urodoidea to Schreckensteinioidea

Ustyurtia zygophyllivora Kaila, Heikkilä & Nupponen

in Kaila, Nupponen, ... et Heikkilä, 2020.

Ustyurtiidae Kaila, Heikkilä & Nupponen, a new family of Urodoidea is introduced. The family is based on the genus Ustyurtia Kaila, Heikkilä & Nupponen, gen. n. The genus includes the type species U. zygophyllivora Kaila, Heikkilä & Nupponen, sp. n. and U. charynica Kaila, Heikkilä & Nupponen, sp. n., both from Kazakhstan. These two species, in particular the immature stages, have morphological attributes apomorphic of Urodoidea. The close affinity is also supported by DNA data based on several markers. We consider this new family warranted due to its sister group position to the remaining Urodoidea and a number of significant morphological differences in wing venation, male genitalia and the structure of the cocoon, apomorphic for Ustyurtiidae on the basis of an earlier published phylogeny. All other recognized genera of Urodoidea belong to the family Urodidae. The closest relatives and phylogenetic position of Urodoidea are not firmly established, but Urodoidea and Schreckensteinioidea have morphological similarities which, in the light of genetic analyses appear synapomorphic and possibly uniting these groups, rather than homoplasious as assumed earlier. The affinities of these superfamilies are discussed.

Keywords: Ditrysia; phylogenetics; morphology; Zygophyllum; Ustyurtia

Ustyurtia zygophyllivora, a moth species new to science that did not belong to any known Lepidoptera family.

Fig. 6. Adults of Ustyurtia zygophyllivora sp. n. in their natural posture, a. male; b. female.

The caterpillars of Ustyurtia zygophyllivora have distinct warning coloration, an indication of their toxicity.

Ustyurtia zygophyllivora sp. n., a. larva in lateral view, displaying the elongate prolegs; b. larva in dorsal aspect. Explanations of abbreviations: D1–2 = dorsal setae 1 and 2, SD = subdorsal setal group, L1–3 = lateral setae, D2 = dorsal seta 2, A8 = segment 8 of abdomen, L1–2 = lateral setae 1 and 2, V = ventral setal group; c. cocoon and pupal exuvia.

Ustyurtiidae Kaila, Heikkilä & Nupponen fam. n.

 Ustyurtia Kaila, Heikkilä & Nupponen, gen. n.

Type species: Ustyurtia zygophyllivora Kaila, Heikkilä & Nupponen, sp. n.

Diagnosis. Ustyurtia is distinguished from all other urodid genera by the stalked Rs3 and Rs4 and the absence of an accessory cell in the forewing. Male genitalia are distinctive from all other urodid genera by the immobile, basally fused valvae, the long, curved, strongly sclerotized uncus, and the vinculum that is prolonged to form a long and slender saccus. The structure of the cocoon is similarly meshed as in other Urodidae. Yet unlike in others, it is densely filled with silk that forms a stiff layer, and has longitudinal ribs that cephalically separate the cocoon into several lobes during adult eclosion. In addition, the male is distinguished from Urodus Herrich-Schäffer, 1854, Wockia Heinemann, 1870 and Incawockia Heppner, 2010 by the absence of a costal hair-pencil in the hind wing. Spiladarcha Meyrick, 1913 and Anomalomeuta Sohn, 2013 have small black dots of raised scales along the upper side of the forewing veins, which are absent from Ustyurtia. From Geoesthia Sohn, 2014, Anomalomeuta, Incawockia, Spiladarcha, and Wockia it also differs by the absence of a patch of raised scales on the forewing median line. From Anchimacheta Walsingham, 1914 and Glaucotunica Sohn, 2014 Ustyurtia differs by the male genitalia, the absence of a bilobed uncus in the latter being one of the most conspicuous differences.

Etymology. The generic name alludes to the geographical origin of the type species, the Ustyurt plateau in southwestern Kazakhstan.

Fig 7: a–d. Ustyurtia zygophyllivora sp. n., a. male holotype; b. male paratype; c. female paratype; d. ovipositor;
e–f. Ustyurtia charynica, sp. n. male. e. holotype, f. paratype.

Ustyurtia zygophyllivora Kaila, Heikkilä & Nupponen sp. n.

Diagnosis. The adult of U. zygophyllivora is very unlike other members of Urodoidea, in being rather narrow-winged and stout-bodied, and the female with a relatively large abdomen and a conspicuous ovipositor. Rather, its appearance resembles that of species of Brachodidae. The forewing is grey, with a pattern of a brownish grey outwardly angled fascia at the basal ⅓ of the wing, and a fused pair of small spots of the same colour at distal ¾ of wing. The male differs from other urodoids in having strongly capsulated genitalia with the valvae immobile and without strong setae or spines. The female genitalia lack a large dilation at base of the ductus seminalis, typical of most representatives of other urodoid genera. Separation of U. zygophyllivora and U. charynica is explained in the diagnosis of U. charynica. The larva possesses the family synapomorphies of Urodidae listed above, and elaborated below. In outer appearance it is colourful with black ground colour and large, black pinacula that are surrounded with circles, and laterally with a broad, orange longitudinal line. The cocoon is shaped as an upturned boat, mesh-structured, densely filled with silk that forms a stiff layer, and with longitudinal ribs that cephalically separate the cocoon into lobes during adult eclosion.

Distribution. SW Kazakhstan. The species is known only from three sites in a restricted area along shores of a large salt lake located in southern Ustyurt plateau.

Biology. The species inhabits gypsum deserts by shores of a salt lake (Fig. 12). Caterpillars appear in early spring, beginning of April in average year, and pupate no later than early May. The larva feeds on Zygophyllum spp. (Zygophyllaceae), preferring flowers at least in early instars. Zygophyllum turcomanicum Fischer ex Kar. and Z. pinnatum Cham. were verified as hosts in the field. Larvae are most active during the hottest time of the day in the early afternoon; they stay exposed all the time. Pupation takes place in a cream-coloured cocoon attached to a stem or branch of the host. Adult males fly at daylight, from early afternoon to late evening. The moth flies rapidly rather short distances (appr. 10 m) close to the soil surface. Its behavior resembles that of a pyralid moth Ratasa alienalis (Eversmann, 1844). Wings of the female are full-sized, but due to the large abdomen the female is probably capable of flying only very short distances, if at all.
Etymology. The species name refers to its larval host plant, Zygophyllum spp.

Ustyurtia charynica Kaila, Heikkilä & Nupponen sp. n.

Diagnosis. Only the male of Ustyurtia charynica is known. It is distinguished from the male of U. zygophyllivora by the wing pattern, male genitalia and DNA barcodes. The forewings of U. charynica are almost unicolourous dark grey with paler grey peppering with a pair of dark grey spots at ¾ wing length barely visible; these markings as well as a dark, outwards angled fascia at ⅓ wing length, are distinctive in the considerably paler U. zygophyllivora. The base of the uncus is narrower in U. charynica than in U. zygophyllivora. The uncus is also somewhat dorsally directed in U. zygophyllivora, unlike in U. charynica. In dorsal aspect the tegumen is narrower in U. charynica than in U. zygophyllivora. The apex of the ventral margin of the valva is blunter and less tapered in U. charynica than in U. zygophyllivora.

Distribution. SE Kazakhstan, Charyn.

Biology. The specimens were swept in the forenoon at a rocky steppe slope with sparse vegetation. Zygophyllum sp. was present at the collecting site.

Etymology. The species name refers to its geographical origin, the Charyn canyon in southeastern Kazakhstan.

Fig. 12. Host-plant and habitat of Ustyurtia zygophyllivora sp. n.,
a. Zygophyllum pinnatum. b. and c. Gypsum desert of Onere along the southern shore of the salt lake, Ustyurt Nature Reserve, SW Kazakhstan.

The habitat of the Ustyurtia zygophyllivora species is the extremely arid and rugged gypsum desert in Kazakhstan.

The newly described family Ustyurtiidae shares most traits specific to Urodidae (Urodoidea), yet differs in some significant ways from other constituent genera. This, along with its position based on molecular analyses, supports its status as a distinct family of Urodoidea and the sister group relationship between Ustyurtiidae and Urodidae. The only molecular analyses that include both Schreckensteinioidea and Urodoidea give a signal, yet weak, that these superfamilies might be closely related. This view is supported by a number of shared immature characters. However, we deem the current evidence not sufficient to unite these superfamilies, pending on better coverage of immature stages of more urodoid genera or stronger molecular support.

Lauri Kaila, Kari Nupponen, Pavel Yu. Gorbunov, Marko Mutanen and Maria Heikkilä. 2020. Ustyurtiidae, A New Family of Urodoidea with Description of A New Genus and Two Species from Kazakhstan, and Discussion on Possible Affinity of Urodoidea to Schreckensteinioidea (Lepidoptera).  Insect Systematics & Evolution. 51(3); 444–471. DOI:  10.1163/1876312X-00002209
Finnish researchers discover a new moth family via @helsinkiuni @EurekAlert