Hermetia goncalvensi Albuquerque, 1955

Fachin, Diego Aguilar & Carvalho-Filho, Fernando Da Silva, 2020, New findings on the Neotropical species Hermetia goncalvensi Albuquerque, 1955 (Diptera: Stratiomyidae): redescription, puparium, and geographical records, Zootaxa 4755 (3), pp. 515-530 : 517-523

Hermetia goncalvensi Albuquerque, 1955

( Figs 1–47 )

Hermetia goncalvesi Albuquerque, 1955: 129 (original description). Type locality: Brazil, Bahia, Salvador, “Eng. Velho” [Engenho Velho]. HT ♂ [MNRJ, presumed lost].

Diagnosis. Species mostly black with short, appressed and yellowish pilosity, but not forming any specific pattern on thorax or abdomen ( Figs 1–2 ). Upper frons mostly black, with two small yellowish areas at the level of anterior ocellus and other two ventrally; face with a long beak-like projection, mostly dark brown, but yellowish dorsally ( Figs 5–8 ). Wing infuscate with dark brown along the anterior portion, darker on basal two-thirds ( Figs 12–13 ). Abdomen with a semi-translucent area on distal margin of tergite 1 and most of tergite 2, in males ( Fig. 1 ); same semi-translucent area but reduced in females ( Fig. 2 ).

Material examined: 2 ♀, BRAZIL, Maranhão, Bom Jardim, REBIO, Res. Biol . [ Reserva Biológica ] Gurupi [3.761°S 46.749°W], armadilha suspensa, 17–27.i.2010, F. Limeira-de-Oliveira, J.T. Câmara & M.B. Aguiar Neto, cols ( CZMA); 1 ♀, 01–06.xi.2010, F. Limeira-de-Oliveira, E.A.S. Barbosa & G.A. Reis ( CZMA); 2 ♀, armadilha luminosa Base , 05–15.vi.2010, J.C. Silva, J.A. Silva, A.A. Santos & T.T.A. Silva ( CZMA); 1 ♀ (terminalia dis- sected, kept in a microvial with glycerin; antennae and left wing slide-mounted in a permanent slide), armadilha suspensa, 01–05.i.2011, M.M. Abreu, E.A.S. Barbosa & A.A. Santos, cols ( CZMA). 1 ♀, Carolina, PARNA [ Parque Nacional ] Chapada das Mesas , Riacho Corrente , 298 m, 07°04’29.2”S 47°05’42.2”W, suspensa simples (15 m), 01–10.x.2013, J.A. Rafael, F. Limeira-de-Oliveira & T.T.A. Silva, cols ( CZMA). 1 ♀ (terminalia dissected, kept in a microvial with glycerin), C.N. Maranhão [Centro Novo do Maranhão], REBIO, Res. Biol . [ Reserva Biológica ] Gurupi , 03°14’05”S 46°41’83”W, armadilha suspensa, 07–15.i.2011, F. Limeira-de-Oliveira & D.W.A. Marques ( CZMA). 1 ♀, Mirador, Parque Est. [ Estadual ] Mirador , Base dos Cágados , 06°46’29”S 45°06’28”W, armadilha de Malaise , 26.xi–03.xii.2011, F. Limeira-de-Oliveira & D.W.A. Marques, cols ( CZMA). 1 ♀, Pará, Bragança, Ajuruteua , 30.viii–04.ix.1988, armadilha suspensa 1,6 m, I.S. Gorayeb ( MPEG). 1 ♀, Belém, Floresta APEG [ Área de Pesquisas Ecológicas do Guamá – Reserva do Mocambo ], 1°26’20”S 48°25’18”W, 17–21.xii.1982, armadilha suspensa 23 m, I.S. Gorayeb ( MPEG); 1 ♂ (terminalia dissected, kept in a microvial with glycerin; antennae and left wing slide-mounted in a permanent slide), 1 ♀ (antennae slide-mounted on coverslips, pinned beneath the specimen), Campus de Pesquisa do Museu Paraense Emílio Goeldi, 1°27’07.02”S 48°26’37.03”W, 28.iii.2014, detritos dentro de bambu apodrecido ocupado por Camponotus, F.S. Carvalho-Filho ( MPEG). 1 ♀, São Geraldo do Araguaia, Serra das Andorinhas , [ Vila ] Sta [ Santa ] Cruz , 6°12’58.8”S 48°26’1.6”W, 01–10.xii.2001, margem rio, armadilha suspensa 1, 6 m, I.S. Gorayeb, A. Tavares, J.M.F. Ribeiro, L.A.S. Souza, cols ( MPEG). 2 ♀, São Geraldo do Araguaia, Cerrado , Serra Martírios-Andorinhas , 06°14’20”S 48°28’18”W, armadilha suspensa, 06.xii.2006, E.M. Santos, R.L. Trindade, O. Souza, S. Souza, D.D.R. Guimarães, cols ( MPEG); 2 ♀, 08.xii.2006 ( MPEG). 1 ♀, Parauapebas, Serra Norte [ Serra dos Carajás ], [ Estrada da] Fofoca , [6°04’04”S 49°54’07”W], 21.viii.1984, armadilha suspensa 1,6 m, T. Pimentel, MPEG DIP 12140493 ( MPEG); 1 ♀, 07–10.ix.1985, armadilha suspensa 20 m, MPEG DIP 12140494 ( MPEG). 1 ♀, Est. [Estrada do] Manganês , 6°6’58.464”S 50°17’22.805”W, 18.vi.1984, armadilha sus- pensa 1, 6 m, T. Pimentel, MPEG DIP 12140500 ( MPEG); 1 ♀, 27.vi–01.vii.1985, MPEG DIP 12140497 ( MPEG); 1 ♀, 06–09.ix.1985, armadilha suspensa 20 m, F.F. Ramos, MPEG DIP 12140502 ( MPEG). 1 ♀, N-3, 6° 02’30”S 50°12’26”W, 23–26.vi.1985, armadilha suspensa 2 m, MPEG DIP 12140495 ( MPEG); 1 ♀, 30.vi–02.vii.1985, armadilha suspensa 15 m, MPEG DIP 12140496 ( MPEG). 1 ♀, Piauí, Piracuruca, P.N. [ Parque Nacional ] de Sete Cidades , Posto do ICMBio, 04°05’57”S 41°42’34”W, armadilha suspensa, 13–25.iv.2013, F. Limeira-de-Oliveira, T.T.A. Silva, cols ( CZMA); 1 ♀, 18–28.v.2013, F. Limeira-de-Oliveira, T.T.A. Silva, cols ( CZMA). 1 ♀ (terminalia dissected, kept in a microvial with glycerin), Rondônia, Porto Velho, Rio Madeira , 09°35’29.5”S 65°2’57.60”W, Malaise , 8ª camp. T5 e T7, 09–19.ix.2011, T.F. Carrijo ( MZUSP, MZ 052907). 1 ♀, Roraima, Ilha de Maracá, Rio Uraricoera , 21–30.xi.1987, armadilha Malaise, J.A. Rafael e equipe ( INPA).

Redescription. Male. Length: body, 8 mm; wing, 7 mm. Head ( Figs 3, 5, 7, 9 ). Dichoptic eyes, head wider than long in dorsal view, higher than wide in lateral view. Eyes covered in short brown setae. Occiput black, except for one yellowish mark at the edge with vertex, short golden pilosity covering most of the surface. Vertex black, short, with long yellowish pilosity. Ocellar tubercle black, prominent, slightly higher than upper frons. Upper frons mostly black, except for one roughly circular yellow spot at the level of anterior ocellus, diverging ventrally, virtually covered by short yellowish setae; with a bulging medial area, visible in profile, its cuticular surface shining and bare. Frontal callus prominent, dark brown with a yellowish area on lateral margin of eye dorsally and surrounding the insertion of antenna, which extends to beak-like process of face; face dark brown, with a medial yellowish mark on dorsal surface of beak-like process. Antenna longer than head, dark brown; scape twice as long as pedicel; flagellum with eight flagellomeres ( Fig. 3 ), with a depressed sensory area on inner side which extends from flagellomeres 4 to 6 (see Pezzi et al. 2017: 926, fig. 1 for Hermetia illucens details); first seven cylindrical, shortening towards terminal flagellomere, with seventh smaller in size compared to sixth, each shorter than previous flagellomere; terminal flagellomere longer than combined length of seven basal flagellomeres, modified into a flattened, bladelike stylus, with an oval concavity densely setulose on both sides, margins densely covered in short, dark brown to black setae. Clypeus subrectangular, slightly longer than wide, strongly sclerotized. Maxillary palpus short, dark brown to black, bi-segmented. Proboscis short, dark brown to black, with long, sparse, yellowish pilosity. Thorax. Scutum dark brown to black, with pale yellowish markings on postpronotal lobe, lateral margin of presutural scutum near transverse suture and postalar callus; pilosity appressed, short, white to pale yellow, with longer tufts at lateral margin; scutellum dark brown to black, distal margin yellowish, with pilosity short, pale yellow; mediotergite black, shinning, lateral margin covered in moderately long, whitish setae, sparse at center ( Fig. 11 ); pleuron mostly dark brown, with pale yellow markings on proepimeron, posterior margin of anepimeron, proximal area of meron and postero-dorsal area of laterotergite; pilosity short, white to pale yellow. Legs mostly dark brown, tip of fore femur, base of tibia and fore and mid tarsomeres yellowish, with last three in mid leg darkening towards apex; dorsal face of basal third of hind tibia and dorsal face of hind two first tarsomeres white to pale yellow; pilosity short, white to pale yellow. Wing ( Fig. 12 ). Slightly brownish, darkest along the anterior margin, encompassing cells bc, c, sc, br, bm, anterobasal part of cua, entire discal cell, r 1, r 2+3, r 4, and anterior two-thirds of r 5, with the brown coloration not quite reaching wing apex; R 2+3 beyond r–m origin at discal cell, arising at a distance roughly as long as r–m length. M 2 not reaching wing margin. Alula bare. Halter pale yellow, with basal third of stem marked with dark brown. Abdomen. Subrectangular, two times longer than wide, with tergites 2–4 of similar width; first segment much narrower proximally than distally, margins divergent; only basal third of second segment with lateral margins divergent; abdomen tapering from distal half of fourth segment to sixth. Tergite 1 mostly dark brown, with extreme posterior margin pale yellow; tergite 2 semi-translucent, dark brown at extreme lateral margin only; tergites 3–5 dark brown to black; pilosity long, dense, erect and white on lateral margin of tergite 1, and short, dense, appressed and white on posterior two-thirds of tergites 2 and entire surface of remaining tergites. Sternites 1–2 entirely pale yellow, with darker markings limited to extreme lateral margins; remaining sternites black; pilosity short, dense, appressed and white on entire surface of sternites. Terminalia ( Figs 14–27 ). Sternite 8 reduced, cylindrical, tip and base subtriangular; tergite 8 reduced, slender, C-shaped in dorsal view. Genital capsule (synsternite) elongate, subrectangular, distal margin not beyond gonostylus margin; cercus exceeding distal margin of genital capsule when epandrium at rest; longitudinal extension of gonocoxal apodeme roughly as long as genital capsule length; medial process well developed, tapering towards apex. Anterior end of gonocoxal apodeme and anterior end of phallus exceeding anterior margin of genitalia in about half its length; gonocoxal bridge absent. Phallus long, three large nearly symmetrical lobes, separated from each other throughout extension; medial lobe slightly shorter than lateral ones. Parameral sheath connected to phallus base ventrally, with two arms projected dorsally. Gonostylus as wide as long, triangularly produced on distal and proximal margins, with a smaller projection medially. Epandrium V-shaped, with anterior margin emarginated but as long as medial part, posterior margin rounded and projected towards anterior margin of proctiger. Epandrium articulation with genital capsule at anterior end, with epandrium weakly expanded below the anterior level. Proctiger (tergite 10) elliptical, as long as cercus; sternite 10 well developed, as long as epandrium; cercus rod-shaped, enlarging towards apex.

Female. Similar to male, except as follows: Length: body, 8–13 mm; wing, 9–13 mm. Head ( Figs 6, 8, 10 ). Usually lighter coloration than in males, with yellowish areas wider on upper frons and face (see also Fig. 47 , A–I). Antenna 1.5 times as long as male antenna ( Fig. 4 ); first five flagellomeres longer than wide, sixth as long as wide, seventh minute, terminal flagellomere shorter than length of the seventh flagellomeres combined, roughly half of the length. Distal segment of palpus enlarged. Abdomen. Oval, wider on second segment, tapering towards apex. Semi-translucent area on tergites 1–2 reduced in size, half width of that in males, in tergite 2 restricted to proximal half, not reaching extreme lateral and distal margins. Terminalia ( Figs 28–29 ). Tergite 8 rectangular; sternite 8 longer than tergite 8, subtriangular on its distal fourth. Tergite 9 sclerotized, anterior half with parallel margin, divergent posteriorly. Genital fork (sternite 9) widest medially, gradually narrowing towards a long and slender anterior end; posterior bridge weakly bilobed; posterolateral process converging, narrower basally, distally rounded and expanded; genital opening large, circular. Tergite 10 well developed, subtriangular. First segment of cercus nearly twice as long as second segment.

Puparium. Total length (n=2) 10.4–10.6 mm. Cuticle with usual mosaic appearance ( Figs 39 , 44–46 ). Chromatic pattern dark brown. Head. Prominent, moderately flattened dorsally, longer than wide, conical in lateral view, with lateral margin slight waved ( Figs 30–31 , 36–37 ). Cuticle with usual mosaic appearance, except in a median region of distal half and at base of antenna in dorsal view ( Figs 31–32 ). Mandibular-maxillary complex composed of a rigid, cylindrical structure with rounded tip, shorter than labrum in dorsal view ( Figs 31–32 ), with a cluster of three very small pointed sensillae dorsally in the distal half ( Fig. 31 ). Labrum triangular with rounded tip ventrally directed ( Figs 31–32, 35 ). Antenna (ant) small, two-segmented; basal antennomere (ba) wider than long, well developed, and semi-spherical; apical antennomere (aa) at least three times longer, conical ( Fig. 33 ); rod-like sensillum (sn) almost as long as apical segment and placed lateral to it ( Fig. 33 ); antenna placed in a well-developed circular cavity, dorsal-laterally arising from the anterior part of head ( Figs 30–31, 33 ). Eye (e) prominent, rounded, arising at the middle part of head ( Figs 30, 31 ). Molar area (mo) distinct transversely ridged ( Fig. 37 ). Chaetotaxy ( Figs 31–32 , 36–37 ): 2 pairs of labral setae (LB), 2 pairs of clypeofrontal setae (CF), 1 pair of lateral setae (L), 1 pair of dorsolateral setae (DL), 1 pair of sublabral setae (SL), 3 pairs of ventrolateral setae (VL), and 3 pairs of ventral setae (V). Setae of head laterally flattened and barbed, usually lanceolate ( Figs 32 , 38 ). Thorax. Prothorax shorter than meso- and metathorax; chaetotaxy ( Figs 32 , 36 , 40, 41 ): with 2 rows of setae, 2 pairs of anterodorsal setae (AD) and 2 pairs of dorsal setae (D); in ventral view, 2 pairs of ventral setae (V), and 1 pair of ventrolateral setae (VL) ( Figs 34 , 36 ); prothoracic spiracle (prth spr) sclerotized, prominent, lacking setae, with a rounded bulge anteriorly and a posterior enlarged bulge where the spiracular scars are located ( Fig. 34 ). Meso- and metathorax with one row of setae each, 3 pairs of dorsal setae (D) and 3 pairs of ventral setae (V). Metathoracic spiracle (mtth spr) small and rounded. Setae of thorax laterally flattened and barbed. Abdomen. Abdominal segments 1 to 7 similar in shape, slightly tapering from segment 4 to 7 ( Figs 40–41 ); abdominal spiracles (abd spr) on abdominal segments 1 to 7 small and rounded ( Fig. 40 ); chaetotaxy ( Figs 40, 41 ): with a row of 3 pairs of dorsal setae (D); 3 pairs of ventral setae (V) and 1 pair of ventrolateral setae (VL) near the external margin of the body; in lateral view, 1 pair of lateral setae (L), 1 pair of dorsolateral (DL) and 1 pair of ventrolateral (VL). Segment 8 about 1.5 times as wide as long, tapering towards posterior margin ( Figs 42–43 ); posterior margin strongly concave ( Figs 40–41 ); cleft of posterior spiracular opening (p spr o) placed dorsally on segment 8, somewhat convex, partly hidden by a fold of integument and somewhat shifted to posterior margin of segment, placed near the posterior margin, with lower lip of opening bordered by flat and pinnate setae (pns) ( Figs 42, 45 ); transverse integumentary fold with about the same length of distal half of segment 8 ( Fig. 42 ); anal slit (asl) with about one-third of length of segment 8, placed in the distal half, near the posterior margin ( Fig. 43 ); chaetotaxy: 1 pair of dorsocentral setae (DC), 1 pair of lateral setae (L), 1 pair of apical setae (AP), 1 subapical setae (SAP), 5 pairs of ventral setae (V) ( Figs 40–43 ).

Notes on natural history. Larvae were found in detritus accumulated in internodes of a rotting piece of an exotic oriental bamboo ( Bambusa vulgaris Schrad. ex J.C. Wendl. ) found on the ground of a secondary forest in the Brazilian Amazon. The bamboo was occupied by a colony of carpenter ants ( Camponotus Mayr, 1861 ).

Mimicry seems to play an important role in Hermetia . Most species of the genus resemble wasps such as H. aurinotata Lindner, 1935 and H. comstocki Williston, 1885 , while some are bee-like such as H. anthidium James in James & Wirth, 1967 . Hermetia goncalvensi is likely a mimic of wasps of the genus Polybia Lepeletier, 1836 ( Hymenoptera : Vespidae ) (Martin Hauser pers. comm.).

Geographic distribution. Brazil (states of Bahia, Maranhão, Pará, Piauí, Rondônia, and Roraima) ( Fig. 47 ).

Comments. In the original description, Albuquerque (1955) provided illustrations of the male holotype, including terminalia. It differs only slightly from the male used in the present redescription by having a dark macula, roughly circular, at the center of the semi-translucent area in the second tergite of the abdomen ( Albuquerque 1955: 130, fig. 4). Besides this feature, which can be variable in specimens of the same sex and between sexes of the same species in many Hermetia species, our male fits well with the concept of H. goncalvensi . The head coloration pattern of the males and females examined here is also consistent with the holotype (see Figs 5–8 ). There is some intraspecific variation (especially within females) regarding the color intensity of the upper frons and facial dark brown areas (see Fig. 47 , A–I), but most specimens had their genitalia checked and matched each other and the male, and with the pattern of the holotype described by Albuquerque (1955: 130, fig. 1). We consider that now the identity of this species is clarified and stable, and even though the holotype is lost, we choose not to designate a neotype.

There is little information on the natural history and immatures of Hermetia . Until now, immature stages of only six species have been described and/or figured, namely H. albitarsis ( Lindner 1965: 86) , H. aurata Bellardi, 1859 ( McFadden 1967: 32) , H. concinna Williston, 1900 ( McFadden 1967: 31) , H. illucens ( McFadden 1967: 30; Roszkošný 1983: 174; Schremmer 1986: 412; Barros et al. 2018), H. panamensis Greene, 1940 ( Greene, 1940: 152) , and H. pulchra ( Pujol-Luz et al. 2016: 360) . Most of these descriptions, however, are short and poorly informative, hampering a comparative analysis of the puparia. The puparium of H. goncalvensis differs from that of H. illucens and H. pulchra by having mandibular-maxillary complex shorter than labrum, segments of thorax and abdomen not densely covered with setae and anal slit displaced distally. Conversely, Hermetia illucens and H. pulchra have mandibular-maxillary complexes almost as long as the labrum, segments of thorax and abdomen covered with many setae, and anal slit displaced proximally.

Figures

FIGURE 47. Geographic distribution of Hermetia goncalvensi, with the distribution of the species and its variations in head coloration on a map of Brazilian biomes (A–I represent female heads of the specimens highlighted in the map).

FIGURES 1–2. Habitus of Hermetia goncalvensi, dorsal view. 1. Male. 2. Female. Scale bar, 1 mm.

FIGURES 3–13. Additional details of Hermetia goncalvensi. 3–4. Antenna (3. Male; 4. Female). 5–6. Head, dorsal view (5. Male; 6. Female). 7–8. Head, frontal view (7. Male; 8. Female). 9–10. Head, lateral view (9. Male; 10. Female). 11. Mediotergite, male. 12–13. Wing (12. Male; 13. Female). Scale bar, 1 mm. Abbreviations: A1, first branch of anal vein; al, alula; an lb, anal lobe; bm, basal medial cell; br, basal radial cell; c, costal cell; C, costal vein; Cu, cubital vein or cubitus; CuA, anterior branch of cubital vein; cua, anterior cubital cell; CuA+CuP, anterior branch of cubital vein + posterior branch of cubital vein; CuP, posterior branch of cubital vein; cup, posterior cubital cell; d, discal cell; flg, flagellum; flgm, flagellomere; h, humeral crossvein; M, medial vein or media; M1, first branch of media; m1, first medial cell; M1+2, fused first and second branch of media; M2, second branch of media; m2+3, fused second and third cell of media; M3, third branch of media; M3+4, fused third and fourth branch of media; M4, fourth branch of media; m4, fourth medial cell; m–cu, medial–cubital crossvein; m–m, medial crossvein; ped, pedicel; R1, anterior branch of radius; r1, first radial cell; R2+3, second branch of radius; r2+3, second + third radial cell; r4, fourth radial cell; R4, upper branch of third branch of radius; r5, fifth radial cell; R5, lower branch of third branch of radius; r–m, radial–medial crossvein; Rs, radial sector; sc, subcostal cell; Sc, subcostal vein; scp, scape.

FIGURES 14–23. Male terminalia of Hermetia goncalvensi. 14. Sternite 8, ventral view. 15. Tergite 8, ventral view. 16–17. Genitalia, dorsal and lateral views, respectively. 18. Epandrium, proctiger and cerci, dorsal view. 19–20. Phallus, dorsal and lateral views, respectively. 21. Genitalia with phallus, dorsal view. 22–23. Genitalia with phallus, epandrium, proctiger and cerci removed, dorsal and ventral views, respectively. Scale bar, 0.1 mm.Abbreviations: cerc, cercus; epand, epandrium; goncx apod, gonocoxal apodeme; gonst, gonostylus; mps, median process of systernite; ph, phallus; pm sh, parameral sheath; prct, proctiger; st, sternite; synst, systernite; tg, tergite.

FIGURES 24–29. Male and female terminalia of Hermetia goncalvensi (24–27. Male; 28–29. Female). 24. Genitalia, dorsal view. 25. Genitalia, ventral view. 26. Phallus, dorsal view. 27. Epandrium, proctiger and cerci, dorsal view. 28. Terminalia, dorsal view. 29. Genital fork, dorsal view. Abbreviations: cerc, cercus; epand, epandrium; go, genital opening; goncx apod, gonocoxal apodeme; gonst, gonostylus; mps, median process of systernite; pb, posterior bridge; ph, phallus; pm sh, parameral sheath; pp, posterolateral process; prct, proctiger; spmth dt, spermathecal duct; st, sternite; synst, systernite; tg, tergite.

FIGURES 30–35. Puparium of Hermetia goncalvensi, head and prothorax, dorsal view. 30. Head and prothorax. 31. Head in detail. 32. Clypeofrontal seta. 33.Antenna. 34. Prothoracic spiracle. 35. Labrum.Abbreviations: ant, antenna; aa, anterior antennomere; AD, anterodorsal seta; ba, basal antennomere; CF, clypeofrontal setae; D, dorsal seta; DL, dorsolateral seta; e, eye; LB, labral seta; prth spr, prothoracic spiracle; sn, sensilla; VL, ventrolateral seta.

FIGURES 36–39. Puparium of Hermetia goncalvensi, head and prothorax, ventral view. 36. Head and prothorax. 37. Head in detail. 38. Ventrolateral seta. 39. Detail of tegument of prothorax. Abbreviations: mo, molar area; V, ventral seta; VL, ventrolateral seta.

FIGURES 40–46. Puparium of Hermetia goncalvensi, thorax and abdomen. 40. Meso- and metathorax, and abdominal segments 1–8, dorsal view. 41. Meso- and metathorax, and abdominal segments 1–8, ventral view. 42. Abdominal segments 7–8, dorsal view. 43. Abdominal segments 7–8, ventral view. 44. Dorsal seta of abdominal segment. 45. Terminal portion of segment 8, ventral view. 46. Detail of tegument of segment 8. Abbreviations: abd spr, abdominal spiracle; AP, apical seta; asl, anal slit; D, dorsal seta; DC, dorsocentral seta; DL, dorsolateral seta; L, lateral seta; pns, pinnate seta; p spr o, posterior spiracular opening; SAP, subapical seta; V, ventral seta; VL, ventrolateral seta.