Apiochaeta lenticula, Lonsdale & Marshall, 2008

Lonsdale, Owen & Marshall, Stephen A., 2008, Revision of the temperate South American genus Apiochaeta Czerny, 1903, with synonymy of Alloclusia Hendel, 1917 (Diptera: Clusiidae), Zootaxa 1944 (1), pp. 1-33 : 18-20

Apiochaeta lenticula sp. n.

Figs 7 , 19, 20 , 39

Description ( Fig. 7 )

Male. Body length 4.0–6.0mm. Arista pubescent. Postvertical bristle half length of ocellar bristle. Three fronto-orbital bristles. One pair of lateral scutellar bristles (paratype with two pairs on right side) that are longer than apical pair. Scutum yellow with one pair of stripes extending slightly past suture. Scutellum yellow. Pleuron yellow with brown subnotal stripe on anepimeron, katatergite, and dorsal half of anepisternum (ventral margins of sclerites yellow, sometimes excluding katatergite), occasionally continuing onto lateral half of postpronotum. Legs yellow. Head yellow with ocellar tubercle brown, face brown to dirty white, gena white, parafacial brown, occiput white with dark yellow to brown spot behind lower margin of eye, back of head with one pair stripes radiating from foramen and first flagellomere usually with small infuscation around base of arista; occiput and dorsal 1/3 of gena silvery tomentose. Abdomen brown with tergite 1 and surstylus yellow. Wing clouded around dm-cu and around tips of R 2+3, R 4+5 and M 1.

Female. As described for male except as follows: face and parafacial yellow; stripes behind head sometimes very thin; anatergite sometimes light brown lateral to scutellum; tergite 2 sometimes with one pair of central yellow spots (if central spots absent, posterior margins of tergites 3–5 variously yellow medially).

Male terminalia ( Figs 19, 20 & 39 ). Annulus well developed with tergite 7 weak. Height, length and width of epandrium subequal. Cerci small and rounded with shallow medial emargination. Surstylus nearly as high as epandrium, strongly hooked, thin distally and with transverse basal shelf; small rounded bristles along margin of shelf and along inner-distal margin. Phallapodeme thick medially and sinuate on anterior margin. Hypandrial arm well developed and ventral lobe thin with two long medial bristles. Basiphallus well developed. Epiphallus curved anteriorly. Pregonite nearly ovate with five medial bristles. Postgonite stout and elongate with three distal bristles. Distiphallus with right margin long and bifid (apical forks unequal in length); lateral sclerotizations minutely spinulose at midpoint and with minute medial process.

Etymology: The specific name is derived from the Latin for “freckle”, referring to the spot on the occiput of this, and two related species.

Holotype: CHILE. Aysén: Río Mañiguales, 72°30’W, 45°25’S, 26–28.i.1961, L.E. Peña (♂, CNC).

Paratypes: CHILE. Arauco: Pichinahuel, Cord. Nahuelbuta , 15.i.1959, L.E. Peña (♀, CNC) , Aysén: Puerto Aysén , 24–26.i.1961 (♀, DEBU) , Río Mañiguales, 72°30’W, 45°25’S, 26–28.i.1961, L.E. Peña (♀, CNC; ♂, DEBU), Puerto Cisnes, 72°40’W, 44°45’S, 16–28.ii.1961, L.E. Peña (♀, CNC; ♀, USNM), Puerto Cristal , Lag. , Buenos Aires , Aysén , 9–10.i.1961, L. Peña (♀, CNC) , Chiloé: Isla Chiloé, Ahoni Alto , ix.1998, L.E. Peña (♀, CMNH) , Osorno: Pucatrihue , 4.ii.1967, E.I. Schlinger, 40°28’S, 73°43’W (♀, CASC) ,

Valdivia: Pto. Fui, 16–20.ii.1978, L.E. Peña (♀, DEBU) .

Additional material examined: CHILE: Chiloé: S Chile, Chiloé I., F.&M. Edwards, Ancud , 17– 19.xii.1926 (♀, BMNH) [paratype of A. excepta ], Concepción: 62 km S San Pedro , 12.xii.1982 – 2.i.1983, A. Newton & M. Thayer (♂, CNC) , Malleco: R.I.X, PN Nahuelbuta, 8–24.ii. 2005, 1168m, 37°49’30”S, 72°58’24”W, Malaise trap in meadow and Nothofagus, UCR AtoL (2♀, CNC) .

Comments: Apiochaeta excepta , A. mallochi and A. lenticula all have a single pair of lateral scutellar bristles and a small dark yellow to dark brown spot immediately behind the ventral margin of the eye. Apiochaeta lenticula differs from A. excepta in that it has a more slender hook on the surstylus (similar to A. mallochi ) and a well-developed pair of apical scutellar bristles. Apiochaeta lenticula can be most easily separated from A. mallochi by the difference in size and the colour of the head and pleuron.

Figures

FIGURES 3–9. Wings; 3: Apiochaeta philippii (Rondani); 4: A. pictipennis (Wulp); 5: A. chiloensis (Malloch); 6: A. vitticollis (Blanchard); 7: A. lenticula sp. n.; 8: A. varia (Malloch); 9: A. costalis (Malloch).

FIGURES 19–26. External male terminalia; Figs. 19–20: Apiochaeta lenticula sp. n.; 19: left lateral; 20: posterior; Figs. 21–22: A. excepta (Malloch); 21: left lateral; 22: posterior; Figs. 23–24: A. philippii (Rondani); 23: left lateral; 24: posterior; Figs. 25–26: A. chiloensis (Malloch); 25: left lateral; 26: posterior.

FIGURES 39–43. Internal genitalia, left lateral; 39: Apiochaeta lenticula sp. n.; 40: A. chiloensis (Malloch); 41: A. philippii (Rondani); 42: A. vitticollis (Blanchard); 43: A. pictipennis (Wulp).