Achradocera meridionalis Becker, 1922

Quevedo, Lucas, Capellari, Renato S. & Lamas, Carlos José E., 2024, Taxonomic revision of Achradocera Becker (Diptera: Dolichopodidae), with description of two new species, Zootaxa 5519 (3), pp. 301-344 : 333-336

Achradocera meridionalis Becker, 1922

( Figs 20 , 21 , 26 )

Achradocera meridionalis Becker, 1922: 208 , fig 79. Type-locality: Belize. Type destroyed, HNHM.

Chrysotus contractus Van Duzee, 1929: 21 . Type-locality: La Providencia, Obispo, Guatemala. Syntypes male and female, USNM. syn. nov.

Chrysotus shannoni Van Duzee, 1930: 77 . Type-locality: San Bartolome , Lima, Peru. Type destroyed, USNM. syn. nov.

Diagnosis (male). Postpedicel longer than arista-like stylus; lower postoccipital setae dense. Legs mostly yellow, except for FIII, basal half and dorsal surface of FI and FII, TI at middle and apical 1/4, TII at apical half, TIII at basal 1/4 and apical 1/5, and distal tarsi, which are all brown infuscated; TI slightly bent, bearing ventral row of conspicuous setae; TII bulged ventrally in middle, with two ventral rows along swelling, then constricted at apical 1/3 to apex, forming excavation; IIt 1 arched, with ring of setae at basal 1/3 and anteroventral tubercule within ring; FIII bulged on basal half and concave below, bearing cluster of strong and long setae near middle of anterior surface; IIIt 3–4 concave. Hypopygium small; surstylus subtriangular, tapered and bearing 1 apical and 1 subapical strong seta; postgonite enlarged and covered by small setae.

Redescription. Similar to A. angustifacies stat. rev., except as noted. Male. Body length: 2.4–2.6 mm. Wing: 2.25–2.35 mm long, 0.75–0.85 mm wide. Antenna. Postpedicel longer than arista-like stylus; FAr ratio, 1.27.

Thorax. 8–10 ac and 5 dc pairs of setae. Wing. CuAx: 0.6; RMx: 1.43; lower calypter yellow with fan bearing about 10 brownish setae; halter pale yellow. Leg I. 35, 38, 18, 8, 5, 4, 4. F entirely dark brown on basal half; T slightly bent, with brownish infuscated at middle and apically, bearing ventral row with distinct setae ( Fig. 20C ) (all MSSC). Leg II. 45, 56, 20, 14, 9, 5, 5. F entirely dark brown on basal half; T bearing anterior seta at basal 1/4, and more 4 setae apically (1 av, 1 pv, 1 ad and 1 pd); T ( Fig. 20E ) bulged ventrally in middle, with two ventral rows along swelling, then constricted at apical 1/3 to apex, forming excavation (MSSC); t 1 ( Fig. 20E ) arched with small av tubercule on basal 1/5 basal with some spines apically, carrying ventral and posterior row of strong decreasing setae, with ad row forming circlet of conspicuous setae (MSSC). Leg III. 35, 40, 13, 9, 5 4, 4. F bulged on basal half and concave below, bearing cluseter of strong, long anterior setae near middle ( Fig. 20G ) (MSSC); T with 2 ad, 3 pd, and 4 apical setae (1 d, 1 ad, 1 av and 1 v); t 3–4 ventrally concave ( Fig. 20D ) (MSSC). Hypopygium. As in Fig. 21A–D , similar to A. angustifacies stat. rev.

Female. Unknown.

Distribution. Belize, Guatemala, Mexico, Peru and Hawaii [probably introduced] ( Fig. 26 ).

Type material examined. Chrysotus contracta : SYNTYPES: 1♂, 1♀, labelled: “LaProvidencia | ObispoGuat”, JM Aldrich | Coll IV–16 [“14” on female’s pin]”, “Type No. | 41036 [“40136” on female’s pin] | U.S.N.M.”, “ Chrysotus contractus | V.D. [ Achradocera contracta on female’s pin]” [ USNM].

Additional material examined. Belize. ♂, “ BELIZE: Stann Creek Dist. | creek at Hummingbird Hwy | 17º03.388′N, 88º34.872′W | 26 FEB 2017, JB Runyon” ; 2♂, “ BELIZE: Stan Creek Distr. | Cockscomb Basin | Tiger Fern Falls 175 m | 16º46.832′N, 88º26.474′W | 23 FEB 2017, JB Runyon” ; 2♂, “ BELIZE, STANN CREEK | Sittee Point | 25 April 1987 | Spangler & Faitoute”, “collected on | riverbank at | Possum Point | BiologicalSta” [ MZUSP]; 1♂, “ BELIZE: Toledo District | Fallen Stone Butterfly Farm | 16º17.52′N; 88º57.71′W | 21 MARCH 2019, JB Runyon”; 2♂, “ BELIZE: Stan Creek Distr. | Mayflower Bocawina NP | Upper Bocawina Falls | 16º55.25′N, 88º24.29′W | 20 FEB 2017, JB Runyon” ; 1♂, “ BELIZE: Toledo District | Deep River at Medina Bank | 16º26.592′N; 88º44.704′W | 20 MARCH 2019, JB Runyon”. Mexico . 1♂, Nuevo León, Santiago municipality (25º23′54.7″ N; 100º08′06.6″ W) [photographic record: https://www.inaturalist.org/observations/108430413]. [ MTEC] .

Remarks. The male holotype of A. meridionalis was housed in HNHM (Budapest) and destroyed during a bombing in the 1956 Hungarian Revolution ( Evenhuis 2006). Nevertheless, Becker’s (1922) original description ensures proper recognition of the species, due to this, and for the following reason, we did not see the need to designate a Neotype: the Belize specimens were compared with the type material of A. contracta and did not show any significant difference, therefore, the male syntype of A. contracta can be used for future investigations into the identity of the species.

Van Duzee (1930) considered his A. shannoni similar to A. meridionalis , as “ it has the middle tibiae and tarsi formed as in C. meridionalis Becker , and C. contractus, Van Duzee [...] C. meridionalis differs from both the others by having the face and the front wholly dull with brown pollen, while the other two have the face green with but little pollen ” (p. 78). Only the labels remain on the holotype pin of A. shannoni , so that no direct examination of the type was possible. Nevertheless, we concluded that the distinctions listed by Van Duzee (1930) between A. contracta and A. shannoni are insufficient to keep them as separate species and we hence considered both as synonyms of A. meridionalis .

Figures

FIGURE 20. Achradocera meridionalis. A. Habitus, left lateral. B. Thorax, dorsal. C. Leg I. D. Tarsomeres of hind leg. E. Mid leg, TII and IIt1. F. Head, frontal. G. Hind leg, FIII. Scale bar: A, 1 mm; B–G, 0.2 mm.

FIGURE 21. Achradocera meridionalis, male genital structures. A. Hypopygium, left lateral. B. Hypopygium, ventral. C. Phallus, ejaculatory apodeme and postgonite, left lateral. D. Postgonite, ventral. Scale bar: 0.1 mm.

FIGURE 26. Distribution map of the genus Achradocera.