Euthycerina pilosa Malloch, 1933

Mortelmans, Jonas & Hendrix, Jef, 2020, Review of Euthycerina Malloch (Diptera, Sciomyzidae), with description of a new species from Chile, Zootaxa 4786 (3), pp. 381-395 : 385-391

Euthycerina pilosa Malloch

( Figs 3b , 4b , 5b , 6 a–d, 7b, 8b)

In total, five type specimens and 14 non-type specimens are known, as described below. Of the five type specimens of E. pilosa deposited in the NHMUK, we studied two – the allotype and one paratype.

Allotype studied NHMUK 010862601 . Adult 1♀. The female allotype has the right hind leg missing, but oth- erwise in good condition. The allotype is preserved dry, pinned on a micropin. The original labels from top to bottom: “Type [round white label with red margin, black printed text]”, “Peulla. 12-13 xii 1926 ”, “S. Chile: Llanquihue prov. , P. & M. Edwards. B.M. 1927-63 ”, “ NHMUK 010862601 ”.

Paratype studied NHMUK 010862602 . Adult 1♂. The male paratype is in relatively poor condition: it is rela- tively poorly mounted, with a micropin inserted laterally through the thorax, but the thorax itself is cracked open. The specimen is still well attached to the pin but might need care in the future. The head is missing, and the abdomen has been removed and is stored in a microvial on the same pin as the rest of the specimen. The original labels from top to bottom: “ Paratype [round white label with yellow margin, black printed text]”,”Castro, 20-22 XI 1926 ”, “S. Chile, Chiloe I., F. & M. Edwards. B.M. 1927-63 ” .

Other specimens studied Adult 1♂. Directly pinned. The original labels from top to bottom: “(Chi) Arboretum Valdivia, -39,792163, -73,262604. 18 XI 2016 ”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♀. Directly pinned. The original labels from top to bottom: “(Chi) Arboretum Valdivia, -39,792163, -73,262604. 17 XII 2016 ”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♂. Directly pinned, abdomen removed and stored in a microvial on the same pin as the rest of the speci- men. The original labels from top to bottom: “(Chi) Llancahue, -39,830581, -73,144683. 23 X 2016 ”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♂. Collected in White Pan Trap ( WPT), dried, and mounted to pin. The original labels from top to bot- tom: “13137 (sample cd), (ch): Region VIII Bio Bio, prov. Chillán, Valle Las Trancas, nr. Reserva Nacional Ñuble (site Ñuble MT & PT 02), 36°55’58.9”S, 71°33’21.0”W, 754m, 6-25 I 2013, WPT 01-10, leg Marc Pollet & Anja De Braekeleer, sorted by M. Pollet 2013”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♂. Collected by sweep netting, dried, and mounted to pin. The original labels from top to bottom: “13290 (sample cd), (ch): Region IX Araucanía, prov Cautín, SE of Curacautín, Cabañas Rio Colorado (site Rio Colorado SW 02), 38°33’49.6”S, 71°47’ 03.8”W, 738m, 10 I 2013, SWN, leg Marc Pollet, sorted by M. Pollet 2013”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♂. Collected in malaise trap ( MT), dried, and mounted to pin. The original labels from top to bottom: “13210 (sample cd), (ch): Region VIII Bio Bio, prov. Chillán, Valle Las Trancas, Cabanas Don Guillermo (site Las Trancas MT 01), 36°54’28.8S, 71°29’36,4”W, 1220m, 7-26 I 2013, MT #1, leg Marc Pollet & Anja De Braekeleer, sorted by M. Pollet 2013”, “ Euthycerina pilosa det. Mortelmans”. MNNC.

Adult 1♂. Collected in malaise trap ( MT), dried, and mounted to pin. The original labels from top to bottom: “13199 (sample cd), (ch): Region VIII Bio Bio, prov. Chillán, Valle Las Trancas, nr. Reserva Nacional Ñuble (site Ñuble MT & PT 01), 36°56’01.9”S, 71°33’14.1”W, 765m, 6-25 I 2013, MT #1, leg Marc Pollet & Anja De Braekel- eer, sorted by M. Pollet 2013”, “ Euthycerina pilosa det. Mortelmans”. RBINS.

Other types, not studied Holotype 1♂. Directly pinned. The original labels from top to bottom: “Type [round white label with red margin, black printed text]”, “ Euthycerina pilosa Type, det. JR Malloch ”, “Puerto Montt. 24 XII 1926 ”, “S. Chile: Llanquihue prov. , F. & M. Edwards. B.M. 1927-63 ”. NHMUK.

Paratype: 1 ♀, Directly pinned. The original labels from top to bottom: “Type [round white label with yellow margin, black printed text]”, “Ensenada, 14 XII – 15 XII 1926 ”, “S. Chile, Llanquihue prov. , F. & M. Edwards. B.M. 1927-63 ”. NHMUK .

Paratype: 1 ♀, Directly pinned. The original labels from top to bottom: “Type [round white label with yellow margin, black printed text]”, “Ancud, 17 XII – 19 XII 1926 ”, “S. Chile, Chiloe islands , F. & M. Edwards. B.M. 1927-63 ”. NHMUK .

Euthycerina pilosa is a relatively large, yellowish species with the scutum only weakly pubescent compared to those of its congeners. Pubescence on thorax most resembling that of E. uachi : five weak longitudinal gray pubescent lines (slender acrostical ( AC), broad dorsocentral ( DC), very broad supralar ( SA)) ( Fig. 7b ). Cell r 1 with 2(3) large hyaline spots. Costa white at base. To various extent a white streak in cell r 2+3 reaching anterior crossvein (because of the absence of brown infuscation in this region) ( Fig. 3b ). Frontal vitta very narrow, often not connected to occipital triangle and always narrower than occipital triangle ( Fig. 4b ).

This species occurs in a relatively small area in central Chile: Los Ríos and Los Lagos provinces ( Fig. 1 ). Despite its limited distribution, the wing markings of this species are highly variable. Among recently collected specimens, some have very characteristic and pronounced wing markings but in all other respects fall well within the concept of E. pilosa ; because we could not find any further differences in morphology, either externally or internally (e.g., male terminalia), we considered this to be simply a variation of E. pilosa .

The CNC and the FSCA yielded in total seven specimens of E. pilosa from Chile (Malloco and Cautín provinces). These specimens were identified in 2014 ( CNC) and 2017 ( FSCA) by W.L. Murphy (pers. comm.).

Figures

FIGURE 1. Map of southern Chile and Argentina, the distribution of the genus Euthycerina Malloch is plotted. Red square: specimens of E. pilosa; red triangle: type specimens of E. pilosa; green square: specimens of E. vittithorax; green triangle: type specimens of E. vittithorax; orange triangle: type specimens of E. uachi. Unidentified specimens of Euthycerina are not plotted. An interactive version of this map is found online (Mortelmans, 2019).

FIGURE 3. Wings of (A) the male holotype E. uachi, (B) the male paratype E. pilosa, and (C) the male paratype of E. vittithorax.

FIGURE 4. Head in dorsolateral view of (A) the male holotype of E. uachi, (B) a male specimen of E. pilosa, and (C) the male paratype of E. vittithorax. Because we had no type material of E. pilosa that included a head, a typical specimen was chosen for this photograph. In addition to the frontal vitta, note the arista, the back of the head, and the color of the scutum, all of which are diagnostic characters.

FIGURE 5. Habitus in lateral view of (A) the male holotype of E. uachi, (B) the male paratype of E. pilosa, and (C) the male paratype of E. vittithorax.

FIGURE 6. Male terminalia of (A–D) the male paratype of E. pilosa; (E–H) the male paratype of E. vittithorax; (I–L) the male holotype of E. uachi. Male terminalia, posterior view (A, E, I); male terminalia, lateral view (B, F, J); male tergite 5, lateral view (C, G, K); male tergite 5, ventral view (D, H, L). Each facet on a row is drawn on the same scale, and the corresponding scale bars indicate 0,5mm.

FIGURE 7. Dorsal view of the mesonotum of the male holotype of E. uachi (A), the male paratype of E. pilosa (B), and the male paratype of E. vittithorax (C). Scale bar same for all three specimens: 1mm.