Atherimorpha nemoralis (Philippi)

Coscarón, S. & Coscarón, M. C., 2008, Additional information on Atherimorpha White (Diptera: Rhagionidae), Journal of Natural History 42 (41 - 42), pp. 2679-2687 : 2680-2682

Atherimorpha nemoralis (Philippi)

( Figures 1A–I )

Leptis nemoralis Philippi, 1865, p. 772

Atherimorpha nemoralis Malloch, 1932, p. 209 ; James, 1975, p. 2.

Female

Wing length 7.0– 7.1 mm. General colouration light brown-grayish. Frons ocellar tubercle, clypeus, cheeks and occiput light brown-grayish pollinose. Eyes violaceous iridescent (relaxed), antennae dark brown, palpi and proboscis light brown, with hairs as beard and legs whitish to brown, in accordance with the light incidence. Bristles of frons and occiput black. Scutum, scutellum, metanotum, pleurae and coxae light brown-grayish pollinose; scutum a little darkened with a thin darkish gray median and 1+1 diffuse submedian vittae. Scutellum with a subquadrate darkish gray spot in the disc centre. Legs light brown, lighter on femora; hind femur a little darkened on distal third. Scutum and tibiae bristles and apical tibial spur dark brown to black. Wings subhyaline with sc and m cells brownish. Halteres light brown darkened on the knob centre. Abdomen light brown darkened on the middle line and anterior third of tergites II–IV, increasing the darkened extension from V to VIII tergites. First tergite mostly blackish.

Frons convergent below, ocellar triangle with three well-evident eyes elevated over border of an irregular transverse sulcus, eyes and postocular area with a subbasal protruded subovoidal clypeus and slowly prominent cheeks ( Figure 1A ). First antennal segment as long as and thinner than the second, and hairs surpassing the height of the second segment. Basal flagellomere pyriform shape, about as long as first and second segments combined. Occiput with isolated robust bristles bordering the eyes and frons superior border. Palpi about as long as the proboscis length, subcylinder shape, distally acuminated, with abundant and long hairs; Labella flexuous. Legs with short hairs, except the robust tibiae bristles, some of them longer than the transverse diameter. Tibial spur 0:2:1. Sc, R1, R2+3 and membrane on m cell with setae dorsally, and more scarce ventrally. Long scutum bristles disposed in 1+1 submedian longitudinal stripes and in prealar tuft. Scutellum bristles arranged

anteriorly and on posterior border. Pleurae with a tuft on katatergite and surpassing to the anatergite.

Genitalia. Tergites IX–X and cerci in accordance with Figure 1C ; distal segment of cerci about as long as wide, and with apical sensorial organ disposed in a circle, and covered by tricuspid sensillae ( Figure 1D ). Genital fork subtriangle shape, accuminted cephalad; basal spermathecal ducts elongated ( Figure 1E ). Hypoginium with eighth sternite subrhomboid shape with strong setae, in particular distally ( Figure 1F ).

Male

Wings 5.5–6.2 mm. Eyes violaceous iridescent (relaxed). General colouration similar to female, but palpi, scutum, scutellum, pleurae, legs and wings more darkened, in particular on hind femur distal portion, and around the abdomen median tergal spots; abdomen brown yellowish with median longitudinal dark brown spot on tergites II–IV or V, and mostly dark brown on tergites V–VII ( Figure 1G ). Wing membrane on r 2+3 with scarce setae. Ocellar tubercle surpassing the eye level.

Genitalia. Hypopigium as Figure 1H ; dystistyle flattened and curvated, with scarce trichomes; aedeagus with endophalic tines short and wide basally. Epandrium as Figure 1I , cerci subquadrate shape.

Material examined

Chile: Chiloe´, Castro one female, one male, ( BM) ; Llanquihue, Puerto Varas , one female, one male ( BM) ; Malleco, Parque Nacional Nahuelbutá , 4.300m, 25-I-1967, coll. L. Stange: one female ( IML) ; Argentina: Neuquén, Villa La Angostura , 12-XII- 1946, coll. H. Hayward: two males ( IML) .

Distribution

Chile: Valdivia, Llanquihue, Chiloe´; Argentina: Neuquen.

Discussion

Our specimens are in accordance with Malloch’s description and material of both sexes from Llanquihue and Chiloé deposited in the British Museum. The closest species is Atherimorpha hirtula (Bigot) , but has the abdominal tergites II–V are yellowish brown, without darker median spots.

Figures

Figure 1. Atherimorpha nemoralis (Philippi). (A–F) female; (A) head, frontal view; (B) wing; (C) epigynium, showing tergite and sternite X and cerci; (D) distal sensorial organ of cercus; (E) genital fork, at right spermatic duct increased; (F) hypoginium showing sternite VIII and gonapophysis; (G–I) male; (G) abdomen, dorsal view; (H) hypopygium (dorsal and ventral view) showing aedeagus, aedeagal apodeme, endophalic apodeme, basistyle and dististyle; (I) epandrium, showing tergites IX, X and cerci.