Doryctobracon fluminensis
Creators: name: Marinho, Cláudia F.
name: Shimbori, Eduardo M.
name: Alvarenga, Clarice D.
name: Zucchi, Roberto A.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Braconidae
Doryctobracon
Doryctobracon fluminensis

description: Doryctobracon fluminensis (Lima, 1938)
Opius fluminensis Lima, 1938:69.
(Figs 1–3, 5–10, 24–32)
Redescription. Body length, 6 mm; antenna with 58 flagellomeres; dorsal head wide (1.5 mm), almost twice the height, polished, and covered with relatively long, pale setae (0.5 mm) (Figs 7a, 28a); vertex straight and elevated in ocellar region (Figs 24, 27). Eye almost circular (Figs 6, 27); temple almost as wide as anteroposterior width of eye (Figs 6, 27); center of face with strong carina that arises immediately above clypeus and ends shortly after torulus (Fig. 26a). Ventral clypeus weakly sinuous, with median lobe slightly protruding and distinctly angular on sides; malar space slightly longer than width of base of mandible; mesosome with few setae, absent on mesoscutum (Figs 8, 30) and mesopleuron (Figs 6, 27), but abundant on propodeum (Figs 9, 31); notaulices complete, smooth and deep (Figs 8, 30); mesopleuron with smooth depression (Figs 6, 27); propodeum with short anterior mid-longitudinal carina, and complete posterior areola, pentagonal, elongated, and relatively narrow from middle, reaching lower edge of propodeum. Anterior end of areola angular, where long straight anterior transverse carina begins and reaches strong lateral longitudinal carina (Figs 9, 31). Transverse carina arises from upper edge of propodeum, and runs downward and outward, bifurcating inferiorly before reaching posterior edge of propodeum. Center of areola smooth, metapleuron setose (Figs 9, 31); metasoma completely smooth and polished (Figs 10, 29). Ovipositor approximately 6 mm long.
Wings. Fore wing with stigma 4.2× longer than wide; with vein r projecting from its midpoint; (RS+M)a sinuous anteriorly and 1.2× longer than 3RSa; 2RS 0.9× longer than 3RSa, 1.2× longer than 1m-cu, and 2.2× longer than r-m; 1m-cu directly in line with 2RS; 3RSa 2.2× longer than r vein; 2M 1.6× longer than 3Rsa (Figs 3, 32). Hind wing with m-cu, distinctly pigmented (Fig. 32).
Color. Distinctly reddish orange, but black on head [antenna (Figs 5, 24, 25), apex of mandible (Fig. 26), and vertex (ocellar triangle) (Figs 7b, 28b)], on mesosoma [wide area of median and lateral lobes of mesoscutum (Figs 8, 30), anterior region of mesopleuron (Figs 6a, 27), mesosternum (Fig. 26b), and posterior leg except apical half of femur and last segment of anterior and middle tarsi (Figs 5, 24)]; metasoma with black bands from segments T4 to T7 (Figs 10, 29) and on ovipositor sheath (Fig. 5). Fore wing darkened (infumate), veins and stigma dark brown (Figs 5, 25, 32).
Distribution. Guaratiba, Rio de Janeiro State, Brazil.
Fruit fly and associated plant. Lima (1938) mentioned that D. fluminensis was described from specimens obtained from Anastrepha fraterculus; however, in the Fiocruz file and on the holotype and allotype labels, the host is given as A. pseudoparallela (Figs 2, 4, 33). Lima (1948) recorded D. fluminensis as a parasitoid of A. parallela in his compilation of South American entomophagous insects, but he did not mention his own record (Lima 1938) nor that of Gonçalves (1938) (see discussion section for additional information on host records).
Specimens examined. Holotype (female) (CEIOC 77185), Allotype (male) (CEIOC 3159).
Comments. The original description was based on the holotype, allotype, and paratype (male, CEIOC No. 2682; not examined). Only the type material is known. Although Lima (1938) described D. fluminensis with black spots on the lobes of the mesoscutum (Figs 8, 30) and the anterior region of the mesopleuron (Figs 6, 27), these spots were neither characterized in detail nor mentioned in the subsequent literature and taxonomic keys. These spots easily separate D. fluminensis from other species of Doryctobracon, except from D. maculatus, which shares the same characteristics, as discussed below. However, the appearance of these black spots is quite particular, and this difference can be used to separate these two species. Examination of the holotype and allotype of D. fluminensis reveals extensive black spots that completely cover the mesoscutal lobes (median and lateral), and their limits, or the intersection of these spots, almost reach the notauli (Figs 8, 30). In D. maculatus, the spots are pitch black, well defined, and are located at the ends of the lobes of the mesoscutum, being widely separated by the orange color of the mesosoma; on the median lobe, the spot is semi-oval, and the lateral lobes have wide black bands that reach the anterolateral region of the scutellum (Marinho et al. 2021) (Fig. 14). In D. fluminensis, the anterior region of the mesopleuron, defined by Lima (1938) as “sternopleuron” (Figs 6a, 27), and mesosternum are black (Fig. 26b). In D. maculatus, the mesopleuron is almost completely black, mainly posteriorly, which continues, covering the mesosternum (Fig. 12b), except for the longitudinal groove on the ventral surface of the mesothorax, which is orange (mesodiscrimen).
Other characteristics can be used to separate these species, such as the color of the head (dorsal) and the structure of the propodeum. The head in D. fluminensis is completely orange, and only the vertex (ocellar triangle) is black (Figs 7b, 28b). D. maculatus also has an orange head; however, an uninterrupted black or dark reddish brown spot or stripe occurs on the frons and vertex (ocellar triangle), ending on the occiput (Figs 12a, 13). In D. fluminensis, the hind coxa is black (Fig. 6b). In D. maculatus, the hind coxa is yellow with three small dark-brown smoky spots arranged circularly (Fig. 12c). Although both these species have an areolate propodeum, they differ in the shape of the areola and the presence of carinae within them. Doryctobracon fluminensis has a propodeum with a short anterior mid-longitudinal carina and a complete posterior areola, pentagonal, elongated, and relatively narrow from the middle, which reaches the lower edge of the propodeum (Figs 9, 31). The anterior end of the areola is angular, where a long straight anterior transverse carina begins and reaches a strong lateral longitudinal carina; the center of the areola is smooth, and many bristles cover the metapleuron (Figs 9, 31). In D. maculatus, the propodeum also has a short mid-anterior longitudinal carina, followed by a complete posterior areola (Figs 15, 34a). However, the areola has anteriorly rounded edges, where two to three short carinae radiate on each side, weakening without reaching the lateral longitudinal carina (Figs 15, 34b); only one, the posterior transverse carina of the areola, reaches the lateral longitudinal carina (Figs 15, 34c). Within the areola are two very weak longitudinal carinae, bending posteriorly (Fig 15, 34d), and another transverse carina at the base (Figs 15, 34e).
Although the spots on the lobes of the mesoscutum and anterior region of the mesopleuron are described as black in D. fluminensis (Lima, 1938) the analysis of the holotype and allotype showed a less-intense color, close to dark brown, particularly in the anterior region of the mesopleuron, mesosternum, and antenna, indicating that the color may have faded with time due to preservation issues. The black dorsal abdominal bands in females, reported by many authors (Muesebeck 1958; Fischer 1964, 1965; Wharton & Marsh 1978) can also be found in males, as observed in the allotype (Figs 10, 29). Furthermore, the vertex of females was defined as lighter than that of males (Wharton & Marsh 1978), but these differences were not observed in the type material examined (holotype and allotype), which have a black vertex (ocellar triangle) (Figs 7b, 28b).
According to the original description (Lima, 1938), D. fluminensis was reared in A. fraterculus (Wiedemann), collected by Aristóteles Silva, with no information on host fruit. However, on the labels of the type material, the host is A. pseudoparallela (Loew) reared in Passiflora sp. (passion fruit) (Figs 2, 4, 33). Information on A. pseudoparallela as host of D. fluminensis was published by Gonçalves (1938), who also reported that this record was obtained by Aristóteles Silva, who collected the specimens described by Lima (1938). Gonçalves (1938) ’s record went practically unnoticed, but Lima’s information (1938) was released by other authors (e. g., Zucchi 2000; Aguiar-Menezes & Menezes 2023).Anyway, A. pseudoparallela should be considered host of D. fluminensis and not A. fraterculus as stated in Lima (1938). Furthermore, passion fruit is the most common host of A. pseudoparallela in Brazil (Zucchi & Moraes 2024).
description: Published as part of Marinho, Cláudia F., Shimbori, Eduardo M., Alvarenga, Clarice D. & Zucchi, Roberto A., 2024, Hidden under darkened wings: the identity of Doryctobracon fluminensis (Lima, 1938) (Hymenoptera: Braconidae) and a new species of the genus from Brazil, pp. 357-370 in Zootaxa 5538 (4) on pages 359-362, DOI: 10.11646/zootaxa.5538.4.4, http://zenodo.org/record/14611939