Aldrichiopa serrata Torres-Domínguez & Mulieri, 2024

Torres-Domínguez, Diana Marcela, Gallardo, Fabiana & Mulieri, Pablo R., 2024, Taxonomic review of the genus Aldrichiopa Guimarães, 1971 (Diptera: Tachinidae) with notes on antennal morphology and description of a new species, Zootaxa 5405 (3), pp. 354-380 : 363-365

Aldrichiopa serrata Torres-Domínguez & Mulieri sp. nov. Figs. 5–6

Diagnosis. Integument shiny dark brown to brown. Parafacial with row of 6–12 setae. Sternite 5 wide (almost twice as wide as long), U-shaped, with posterior lobes rounded, and well-developed membranous transverse band expanded towards the middle part. Surstylus, in posterior view, with outer edge arched. Pregonite plate more than twice as long as wide. Postgonite with finely serrated ventral edge. Hypandrium broad, parallel-sided to slightly convergent and with slightly rounded to truncated apex.

Description. Male: Body length: 3.1–4.2 mm, wing length: 2.2–3.0 mm (n=10).

Coloration ( Fig. 5 ): General coloration shiny dark brown to brown. Frontal vitta reddish brown. Scape shiny dark brown, pedicel dark brown all over, or only lighter near pedicellar depression. Palpus brown. Thorax shiny dark brown to black and legs evenly shiny dark brown to brown. Scutellum completely shiny brown. Tegula and basicosta brown. Abdomen shiny brown, with tergites 3 and 4 with very faint to inconspicuous or marked gray pruinosity.

Head ( Figs. 5C, D ): Row of 4–6 frontal setae reclinate and lateroclinate descending ventrally to the level of arista base. Fronto-orbital plate with one reclinate or lateroclinate and one lateroclinate setae in the anterior region, and two proclinate orbital setae in the posterior region. Parafacial with row of 6–12 strong setae. Facial ridge with 1–2 setulae above vibrissa. Postpedicel very long, more than 4x as long as pedicel.

Thorax ( Figs. 5B, C ): Scutum with 2+1 acrostichal setae, 2+2–3 dorsocentral, 1+2–3 intra-alar; 1+2–3 supraalar setae.

Wing ( Fig. 5E ): R 4+5 dorsally with 4 setae, restricted to the basal region. Section of M between dm-cu y bend of M 1.3x the dm-cu length. Section of M between r-m and dm-cu 1.3x the section between dm-cu and bend of M. Bend of M with or without stump vein. CuA 1 with the anterior region almost 3x the length of the posterior region.

Legs ( Figs. 5A, B ): Preapical anterodorsal and dorsal setae almost equal length on fore tibia. Mid tibia with 2 anterodorsal and 1–2 posterodorsal setae; hind tibia with 2 strong anterodorsal and 2 posterodorsal setae.

Abdomen ( Figs. 5A, F ; 6A ). Mid-dorsal depression of syntergite 1+2 not reaching the hind margin of that segment. Syntergite 1+2 with 2 lateral marginal setae. Tergite 3 and 4 with 2–3 lateral marginal setae. Tergite 5 with a row of 5–6 marginal setae.

Male terminalia ( Fig. 6 ). Sternite 5 wide (almost twice as wide as long), posterior lobes rounded; with a deep median U-shaped cleft, and well-developed membranous transverse band expanded towards the middle part. Cerci almost equal in length to surstylus (lateral and dorsal). Surstylus, in posterior view, with outer edge arched. Pregonite plate more than twice as long as wide, with margins or edges with darker sclerotization than medial region of plate and with distal edge slightly cleft medially and slightly. Postgonite with finely serrated ventral edge. Hypandrium broad, parallel-sided to slightly convergent and with slightly rounded to truncated apex. Basiphallus sclerotized and broad, distiphallus membranous, darkened only basally, very light to transparent, basally broad, equal to or longer than the basiphallus and truncate apex.

Female. Unknown

Type material. Holotype ♂ ( MLPA): “ CHILE, Santiago Prov. / Maipú, Qbrda. La Plata / 510m [m.a.s.l.]. Malaise 33°31′S / 70°47′W [printed]. 3-XI-1967 [white label, handwritten] / N. Hichins [printed]”; “Aldrichiopa ♂ / coracella (Aldr) [white label, handwritten] / R. Cortés [printed] det. [white label, handwritten] 19 [printed] 78 [white label, handwritten]”; “Holotype [printed on red paper] / Aldrichiopa ♂ / serrata sp. nov / Torres det. 2023 [red label, handwritten]”. Holotype with head, thorax, and abdomen up to tergite 5 in good condition, the rest of the abdomen and terminalia detached and preserved in glycerin in a plastic microvial pinned under the specimen.

Paratypes ♂ ( MLPA / MACN): 7 ♂♂, “ ARGENTINA, Río Negro / Cabecera Steffen / 510m [m.a.s.l.] Malaise 41°30′47′′S / 71°36′18,3′′W / 13-XII-2008-25-I-2009 / Garré & Montes de Oca [white label, printed]”; “Paratype [printed on red paper] ♂ / Aldrichiopa / serrata sp. nov / Torres det. 2023 [red label, handwritten]”, and one paratype ( IFML): 1♂ “R. A. Neuquén / Truran Kura SM / Andes 1000 m / 25-X-8-XI-1986 / M. y P. Gentili ”; “COLECCION / INST. – FUND. M. LILLO / (4000) – S. M. TUCUMAN / TUCUMAN - ARGENTINA [light yellow label, printed]”; “Aldrichiopa / coracelia ♂ / (Aldrich) [white label, handwritten] / M.C. Gramajo det. 199 [white label, printed] 6 [white label, handwritten]”; “Paratype [printed on red paper] / Aldrichiopa ♂ / serrata sp. nov / Torres det. 2023 [red label, handwritten]”.

Etymology. The species name is a Latin adjective from serratus meaning serrated, and refers to the minute serrations on the external edge of the male postgonite.

Geographic distribution. ARGENTINA (Río Negro, Neuquén), CHILE (Metropolitana de Santiago) ( Fig. 7 , Table 1 ).

Remarks. The major difference from A. coracella is the presence of serrate postgonites ( Fig. 6E ) and the head generally has more parafacial setae (up to 12 compared to a maximum of 8 in examined A. coracella ) ( Fig. 5C ). Also, there is remarkable silvery pollinosity on abdominal tergites 3–4 in some specimens ( Fig. 5F ), and the mid-dorsal depression on syntergite 1+2 does not reaching the hind margin of that segment. Finally, the male specimen from Neuquén reviewed by Gramajo (1998) as A. coracella corresponds to this new species.

The specimen examined from Chile seems to be part of the study in Quebrada de La Plata carried out by Hichins (1969) and was identified by Cortés in 1978 as A. coracella . Additionally, a specimen of Aldrichiopa belonging to CNC barcoded and available in BOLD System platform is a male specimen (BOLD: CNC1682446) from Chile identified as A. coracella . This specimen has a brown coloration pattern, a great number of parafacial setae, and the silvery pollinose spots of the parafacial and postocular region very similar to the revised specimens of the new species. Furthermore, the COI gene sequence information shows differences with the other two specimens identified as A. coracella in BOLD System platform, it probably may belong to A. serrata sp. nov.

The species of Aldrichiopa are overall uniform in their external morphology. External characters such as body coloration and silver pruinosity on the parafacial and posterior margin of the eye vary inter e intraspecifically. In fact, Aldrich (1934) originally stated that the male paratype from Puerto Varas ( Chile) “differs in having the parafrontal and parafacial almost entirely shining, there is only a small spot of pollen below the level of arista. […] I suspect that this may be a distinct species, but do not think it advisable to give it a name until the variations are better understood”. This suggests that literature records identified as Aldrichiopa coracella may include misidentifications of A. serrata sp. nov.

Figures

FIGURE 5. Aldrichiopa serrata Torres-Domínguez & Mulieri sp. nov. Male, Habitus (A) Dorsal view; (B) Lateral view; Head (C) Lateral view; (D) Frontal view; (E) Wing; (F) Abdomen, black arrows mark gray pruinosity (scale bars = 1 mm).

FIGURE 6. Male terminalia of Aldrichiopa serrata sp. nov. (A) Sternite 5; Genitalia: (B) Lateral view, (C) Posterior view, (D) Ventral view, (E) Detail of postgonite (scale bars = 100 μm). Abbreviations: bph: basiphallus; cer: cerci; dph: distiphallus; ep: epandrium; hyp: hypandrium; pgn: postgonite; prgn plate: pregonite plate; sur: surstylus.

FIGURE 7. Known distribution of the genus Aldrichiopa Guimarães, 1971, see Table 1.