Zealantha, Roháček, 2007

Roháček, Jind ṙich, 2007, Zealantha thorpei gen. et sp. nov. (Diptera: Anthomyzidae), first family representative from New Zealand, Zootaxa 1576 (1576), pp. 1-13 : 3-6

Zealantha , gen. nov.

Type species: Zealantha thorpei sp. nov. (hereby designated)

Etymology: The name is an abbreviated conjunction of “ Zeal [and] + anth [omyz] a ” and is derived from the name of the country ( New Zealand) where the type species was found. Gender feminine.

Diagnosis: (1) Head ( Figs 1, 4) as long as high. (2) Eye large, convex, broadly subovoid, with longest diameter oblique, densely white pilose. (3) Occiput strongly concave. (4) Head velvety grey microtomentose; occiput with a pair of medial silvery grey microtomentose stripes. (5) Frons relatively narrow; frontal triangle narrow and poorly delimited and like ocellar triangle velvety microtomentose; (6) Ocellar triangle flat and ocelli relatively large. (7) Frontal lunule small but distinct. (8) Antenna geniculate between pedicel and 1st flagellomere; pedicel short, simple. (9) Arista short-ciliate. (10) Palpus slender, with 1 distinct subapical seta. Cephalic chaetotaxy: (11) pvt unusually long and crossed; (12) vti longest of cephalic setae (but vte, oc, and posterior ors of almost the same length); (13) vte as long as or slightly shorter than vti; (14) oc inserted outside the ocellar triangle; (15) 3 ors, 2 posterior strong, 1 anterior short, plus 1 microsetula just in front of anterior ors; (16) a single row of minute postocular setulae; (17) 1 long vi and 1 long subvibrissa; (18) peristomal setulae few in number, about twice as long as postoculars.

(19) Thorax slightly narrower than head. (20) Thorax unicolourous, dark, with dense bluish grey velvety microtomentum. Thoracic chaetotaxy: (21) 1 hu, 2 npl (anterior longer); (22) 1 small sa, 1 longer pa; (23) 1 small weak prs; (24) 2 postsutural dc, the anterior relatively strong; (25) ac microsetae in 4 rows in front of suture, in 2 rows behind anterior dc; (26) 2 sc, the apical long, the laterobasal small; (27) 1 well developed ppl; (28) 2 stpl, the anterior only slightly shorter. Legs (29) unicolourous or f 1 and t 1 somewhat darkened; (30) f 1 with short ctenidial spine ( Fig. 19); (31) t 2 with distinct ventroapical seta; (32) male f 3 with posteroventral row of setae, with those in distal part shortened and thickened ( Fig. 16). (33) Wing ( Fig. 3) moderatelly long and wide; (34) wing membrane unicolourous; (35) C with small and sparse spinulae; (36) R 2+3 long, sinuate, parallel to C with apex upcurved to it; (37) R 4+5 very slightly recurved; (38) R 4+5 and M almost parallel; (39) M straight or very slightly bent; (40) discal (dm) cell moderate, widened distally, with r-m situated near its middle; (41) CuA 1 moderately short, not reaching wing margin; (42) A 1 short, ending before wing margin; (43) alula small and narrow.

(44) Male abdomen ochreous to yellow with brown spots in posterolateral corners of T1-T5. (45) T1 separate from T2, at least dorsally; (46) T2-T5 large and broad, wrapping onto ventral side of abdomen; (47) S1- S5 much narrower and paler than terga. Male postabdomen: (48) T6 reduced to membranous bare unpigmented strip; (49) S6-S8 fused dorsolaterally; (50) S6 strongly asymmetrical, very short and transverse; (51) S7 asymmetrical, placed laterally, twice length of S6; (52) S8 relatively long, less asymmetrical and situated dorsally.

Male genitalia ( Figs 5–14). (53) Epandrium medium broad; setosity sparse, with dorsolateral seta longest. (54) Medandrium subtriangular, dorsally acute-angled ( Fig. 6). (55) Cercus small, short, pale. (56) Gonostylus simply formed, setose on inner side, micropubescent on outer side. (57) Hypandrium relatively long, simple, with internal lobes reduced; (58) transandrium ( Fig. 10) simply arched, without caudal process. (59) Pregonite fused to hypandrium, anteriorly flat and incurved, posteriorly somewhat projecting ventrally, with 2 groups of setae. (60) Postgonite robust, widened and flattened ( Fig. 9). (61) Aedeagal part of folding apparatus ( Fig. 14) covered by numerous flat spines arranged in dense curved rows. (62) Connecting sclerite ( Figs 8–10) elongately plate-shaped, situated ventrally to basal membrane. (63) Basal membrane medially with flattened spine-like excrescences. (64) Phallapodeme very robust, with widened and posteriorly forked base. (65) Aedeagus with simple frame-like phallophore and (66) distiphallus composed of larger saccus and slender sclerotized filum. (67) Saccus unusually short, largely sclerotized ( Fig. 14), with membranous part reduced and distally armed by small spinulae only; (68) filum relatively short, formed by 2 elongate sclerites, the ventral being basally robust and heavily sclerotized. (69) Ejacapodeme small, with digitiform projection.

(70) Female abdomen similarly coloured ( Fig. 15) but with broader terga (T2–T6) than in male. (71) Postabdomen ( Figs 17-18) short and broad; (72) T6 and S6 large, both transverse. (73) T7 and S7 fused to form unicolourous ring-shaped tergosternum where the boundary of S7 is indicated by a depressed line; 7th spiracles embedded in tergosternum; (74) T8 plate-shaped, transverse, with rounded posterior corners; (75) S8 short, semicircular, slightly protruding posteroventrally, with a narrow, posteromedial fissure. (76) Internal sclerotization of female genital chamber ( Figs 21–22) formed by 1 pair of posterior flat crooked sclerites and (77) 1 large anterior ovoid annular sclerite. (78) Anterior part of uterus with weakly sclerotized short-cylindrical ventral receptacle ( Fig. 23) having a terminal curved digitiform projection. (79) Accessory gland small, with stalked microglobulae on surface, connected with terminally dilated duct by thin stem. (80) Spermathecae (1+1) very short pyriform ( Fig. 20), with long cervix, body surface plain with some stalked microglobulae, spermathecal duct relatively short and finely ringed. (81) T10 small, transverse, with 1 pair of long medial dorsal setae and some micropubescence around them; (82) S10 ( Fig. 22) wider than T10, simple, almost bare except for posterior marginal setose area. (83) Cercus short and broad, with rich setae.

Discussion: The new genus is best characterized by the combination of the characters No. 2–4, 6, 9, 11, 14–15, 17, 20, 23, 27, 30, 32–35, 44, 54–55, 58–62, 67–68, 71, 73, 75–78, 80, 82 and 83. However, only some of these features can be considered apomorphic and a few of them are obviously unique (U) within the family. These include: (2) eye densely long-pilose (U), (4, 20) head and thorax with peculiar velvety dark bluish grey microtomentum (U), (11) pvt unusually long, (14) oc arising outside the ocellar triangle (this condition is otherwise only known in some species of the genera Stiphrosoma Czerny, 1928 , and Mumetopia Melander, 1913 ), (27) ppl setula longer than usual, (44) abdomen largely ochreous-yellow, (54) medandrium dorsally pointed (U), (60) postgonite robust, widened, (62) connecting sclerites situated ventrally, (67) saccus with reduced membranous part and well sclerotized, (73) T7 and S7 fused to form tergosternal ring, (78) ventral receptacle subcylindrical with terminal curved digitiform projection, (80) spermathecae with simple surface and long cervix, (82) S10 almost bare (micropubescence reduced).

As noted in the introduction the sole member of the new genus resembles an aberrantly coloured Anthomyza species (shared features: similar frontal chaetotaxy, shortly ciliate arista, mesonotal chaetotaxy, f 1 with ctenidial spine, male f 3 with short thickened posteroventral setae, similar wing venation, well developed female tergosternum T7+S7) but the male and female genitalia differ substantially from those of Anthomyza congeners (e.g. by the form of medandrium, postgonite, filum and saccus of distiphallus, construction of female postabdomen, S8, S10, internal sclerites of genital chamber, ventral receptacle, cerci, etc.).

Interestingly, some genitalic features of Zealantha are reminiscent of those of various (and apparently unrelated) genera. For example, the ventrally positioned connecting sclerite and the widened postgonite most resemble those of the Malagasy genus Amnonthomyza Roháček, 1993 which also has dorsally narrowed (but not acute-angled) medandrium and short cercus (see Roháček 1993: 182–189). The short saccus with reduced membranous apical part can also be found in the E. Palaearctic genus Epischnomyia Roháček, 2006 but detailed construction of the saccus is entirely different (composed of extremely large spine-like processes in Epischnomyia ) not to mention other quite dissimilar parts of male genitalia. The form of the female S8 (short, convex, with posteromedial fissure or incision) probably represents the plesiomorphic condition and can be found in various unrelated genera including Amygdalops Lamb, 1914 , Margdalops Roháček & Barraclough, 2003 , Cercagnota Roháček & Freidberg, 1993 , Stiphrosoma Czerny, 1928 , Paranthomyza Czerny, 1902 and Epischnomyia Roháček, 2006 . Similarly, the tergosternal ring probably evolved by the fusion of female T7 and S7 several times within Anthomyzidae because this structure occurs not only in Zealantha but also in most species of Anthomyza Fallén, 1810 , in Cercagnota Roháček & Freidberg, 1993 , Epischnomyia Roháček, 2006 , Receptrixa Roháček, 2006 , Stiphrosoma Czerny, 1928 (where it is dorsally divided), and in the Afrotropical wingless genus Apterosepsis Richards, 1962 (see Roháček 1998). On the other hand, the internal sclerotization of the female genital chamber with large ovoid annular sclerite (character 77) is rather unusual in the known genera of Anthomyzidae . It is most similar to the condition found in Receptrixa Roháček, 2006 which also has small pyriform spermathecae on short broad ducts but differs by the voluminous strongly sclerotized ventral receptacle and many other features (including elongate, apically fused female cerci). However, the form of the ventral receptacle of Zealantha also is distinctive and its simple female spermathecae are distinguished by the long sclerotized cervix.

In summary, the new genus combines various characters known (or similar to those) in a number of genera of Anthomyzidae but it also possesses several unique features which delimit this taxon from them unambiguously. For the time being, none of the decribed genera was recognized to be distinctly allied to Zealantha . It is therefore expected that the related taxa will be found in the future among the hitherto largely unknown anthomyzid fauna of the Australasian, Oceanian and/or Oriental Regions.