Udea momella Mally, 2022
Mally, Richard, Aarvik, Leif, Karisch, Timm, Lees, David C. & Malm, Tobias, 2022, Revision of Afrotropical Udea Guenee in Duponchel, 1845, with description of five new species of the U. ferrugalis (Huebner, 1796) group (Lepidoptera, Crambidae, Spilomelinae), Nota Lepidopterologica 45, pp. 315-353 : 315
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|Udea momella Mally|
Udea momella Mally sp. nov.
Tanzania, Arusha Region, Mount Meru, Arusha National Park, Momella, 1600-1800 m.
Holotype: Tanzania • 1 ♂; Tanganyika sept. [N Tanzania], Mount Meru, Momella; 1600-1800 m a. s. l.; 10-19 Feb. 1964; W. Forster leg.; Mally genitalia dissection no. 1187; ZSM.
Externally, the single known specimen resembles most closely U. ferrugalis (Fig. 2 View Figures 1–5 ). Forewing colouration is not a reliable character distinguishing the two species, as U. ferrugalis can be similarly coloured. Udea momella is best distinguished by the forewing postmedian line, which is a long wide arch spanning from 3/4 length of the costa to about 2/3 length of anal margin, more resembling the forewing pattern of certain Pyraustinae such as Achyra nudalis ( Hübner, 1876) than that of Udea ; in U. ferrugalis , the forewing postmedian line usually forms a wide half-circle around the distal discoidal stigma that leads into an oval loop on the anal side of that stigma before running towards the anal margin. Furthermore, the forewing costa is mostly straight and slightly curved in the distal 1/4, giving the wing apex and the entire forewing a more triangular shape, whereas in U. ferrugalis the distal 1/3 of the forewing costa forms a long curve, resulting in an overall slenderer forewing shape. In U. momella , the hindlegs’ proximal spur pair has a minute outer spur, whereas in U. ferrugalis this spur is well developed and about half as long as the inner spur.
It is also very close to U. ferrugalis in the male genitalia, especially in the shape of uncus, juxta, phallus and cornutus. The clearest differences between the two species are in the orientation of the fibula - ventrad in U. ferrugalis (Fig. 22 View Figures 21–23 ) -, and in the shape of the fibula base, which is as long as the fibula that is protruding from it in U. momella (Fig. 25 View Figures 24–26 ), while the base is only half as long as the fibula in U. ferrugalis .
Description of adults.
Head: Dorsal side ochre-brown, ventral side beige; labial palps porrect, stretched triangular, about twice as long as eye diameter, dorsal side ochre-brown, ventral side beige, laterally with first meron and a narrow ventral area on second meron beige; maxillary palps well developed, long enough to touch each other at apex, terminal meron with spatulate brush of long scales; haustellum fully developed, basally with cream-coloured scales; frons ochre-brown, margins beige, flatly rounded; compound eyes large, hemispherical; antennae ochre-brown, scapus short, hidden in scales of vertex, pedicellus large, somewhat swollen, flagellum about 2/3 length of forewing, anteroventrally with short dense ciliation; vertex in centre and behind ocelli with tuft of long beige and cream-coloured scales, neck dorsally with a crest of a few broadly spatulate scales. Thorax: Ochre-brown dorsally, beige-cream ventrally. Tegulae large, ochre-brown, with lighter brown tip. Legs beige-cream, foreleg with tibia and proximal tarsus with brownish scales. Outer tibial spur half as long as inner spur in midleg, in hindleg distal spur pair with outer spur 2/3 length of inner spur, proximal pair with long inner spur, spanning most of its tarsus segment’s length, and minute, barely visible outer spur, mostly hidden by leg scales around spur (only one hindleg preserved on holotype). Wings: (Fig. 5 View Figures 1–5 ) Forewing length of male 8 mm. Frenulum bristle in male appears to consist of two fused bristles. Forewings with light brownish-orange ground colour, interspersed with brownish scales; costa somewhat darker. Very faint diffuse brownish antemedian line in first quarter of forewing. Proximal discoidal stigma not evident, distal one a diffuse, roughly circular brownish spot. Postmedian line brownish, leaves costa at about 3/4 in an arc around distal discoidal stigma before continuing straight towards 2/3 of anal wing margin. Subterminal area a narrow light orange band devoid of interspersed brownish scales. slightly arching inwards from subapex to subtornus, on terminal side fading into subterminal area. Veins on costa apex and outer margin marked with dark brown dots. Outer fringe basally light orange, followed by a brown line at about 1/3 fringe width, outer 2/3 light brown. Hindwing dorsally with cream ground colour, with veins light orange; proximal discoidal stigma absent, distal discoidal stigma a small brown dot. Postmedial line a diffuse brownish line leaving costa at about 2/3, circling distal discoidal stigma, fading out towards anal margin. Outer margin light brown, broad at apex, narrowing towards tornus; veins on outer margin with dark markings; fringe light orange, much like in forewing’s subterminal area. Ventral wing sides: forewing ochre with brownish subcostal streak, diffuse but clear brown distal discoidal spot, brownish postmedial line in costal half of wing, and clear dark brown dots on vein ends of apical costa and termen; fringe as on dorsal side. Hindwing whitish, semi-transparent, ochre costal band, apex and veins, small brownish discoidal spots, brown postmedial line in costal half of hindwing, vein ends and fringe as on dorsal side. Abdomen: Colour of abdomen not investigated prior to genitalia dissection. Tympanal organs (Fig. 15 View Figures 11–20 ) with lobulus well developed, almost as long as broad. Male genitalia: (Fig. 25 View Figures 24–26 ) Ovate uncus head with stiff bifid, anteriad directed chaetae on dorsal surface, neck slender, elongate, lateral sides sparsely set with stiff chaetae, base of uncus broadly attached to tegumen and each side with a small dorsolaterad protrusion, connection to tegumen laterally notched; tegumen broad, approximately rectangular; vinculum large, together with saccus forming a broad U; saccus broad, U-shaped; juxta large, sclerotised, basal part roughly circular to hexagonal, distal part with parallel sides that taper into a pair of slender ventrad processes, forming a broad U-shaped central recess; valvae long, elongate, slender, narrowest around half costa length; costa slightly concave, apex obtusely rounded, ventral valva margin concave in apical half, at sacculus convex; sacculus large, roughly triangular, dorsal corner closely approaching base of fibula and costa; fibula emerging alongside basal from an elongate base, forming slender fang-like structure bending towards centre of genitalia in situ (but pointing dorsad in the embedded genitalia preparation). Phallus evenly sclerotised, slender, thinnest in mid-section, anteriorly with short coecum; vesica with short, blunt cornutus emerging from an elongate base, further posterior with a sclerotised dentate area. Female genitalia: Unknown.
So far only known from the type locality on the eastern side of Mount Meru in Tanzania.
The species is named after Momella, the type locality located on the eastern flank of Mount Meru.
The species is placed in the U. ferrugalis species group (sensu Mally and Nuss 2011) based on the male exhibiting one of the two apomorphies for the group: the presence of a cluster of small cornuti on the vesica. The second apomorphy concerns female genitalia, which are not available for study at this time.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.