Wallacella guianensis ( Schaus, 1940 ) Mielke & Grehan & Cock, 2020

Mielke, Carlos G. C., Grehan, John R. & Cock, Matthew J. W., 2020, Ghost-moths of Trinidad and Tobago with description of a new genus and a new species (Lepidoptera: Hepialidae), Zootaxa 4758 (1), pp. 181-190 : 184-186

Wallacella guianensis ( Schaus, 1940) , comb. nov.

( Figs 1a, 1b, 2, 3, 4, 5, 6 , 10, 11, 12, 13a, 13b, 13c, 14, 15 )

Diagnosis. The single known species may be recognized using diagnostic attributes of the genus. However, it is also easily recognized by the distinctive posterior abdomen and male genitalia: i) tergal lobe spatulate on the left and digitiform on the right; ii) ventral projection of the saccus pocket-like with posterior edge serrate; iii) number of antenomeres in the male ~67. These characters are unique among all known Neotropical species.

Redescription. Male ( Figs 1a, 1b, 2, 3, 4, 6 , 10, 11, 12, 14 ). Head. Frons dark orangish-brown to brown. Antenna with ~67 antenomeres.

Thorax. Coloured as the head. Legs ( Fig. 10 ). Epiphysis and arolium absent. Forewing length: 22–31 mm; wingspan: 44–60 mm. Forewing dorsally. Elongated, tornus not distinguished; costal margin straight, apex angle sub-obtuse [almost right angled], outer and inner margins convex. Ground colour orangish-brown to brown with four light gray transverse lines ( Fig. 3 ): i) proximal antemedial line almost straight; ii) distal antemedial line oblique (the most oblique one); iii) proximal postmedial line almost in parallel to the proximal antemedial line, and; iv) premarginal line straight or concave which angles outward from M 2 to costal margin; lighter areas present proximally to all the lines. Stigma concolourus with lines, but not always present. Hindwing dorsally. Orangish-brown to brown, generally lighter than forewing. Forewing and hindwing ventrally. Uniformly coloured, light orangish-brown to brown, but paler and without markings. Abdomen ( Figs 11, 12, 14 ). Dorsally as the thorax, ventrally lighter. Tergum VIII with left lobe pronounced and tapered; sternum VIII lunulate and deeply concave anteriorly, with an irregular sclerotized plate of each side posteriorly.

Male genitalia ( Figs 13a, 13b, 13c, 15 ). Tegumen (= intermediate plate) rectangular and slightly curved inward, fused to pseudotegumen. Saccus U–shaped with robust lateral arms and with a conspicuous pocket-like posterior projection; posterior edge of the pocket V-shaped, strongly sclerotized with serrate borders. Left tergal lobe spatulate, right lobe digitiform. Pseudotegumen laterally rectangular, but forming a ring around the phallocrypt that is unfused dorso-posteriorly and strongly fused antero-ventrally, producing a tapered and projected backwards process, serrated antero-ventrally. Fultura inferior (= juxta) subrectangular, enlarged at its base. Fultura superior (= trulleum) subsquare. Valva L-shaped, digitiform, but enlarged at base; tip, base and anterior margin setose. Phallus membranous, as long the height of the genitalia when everted, with several spine-like cornuti.

Female ( Fig. 4 ). Same pattern as the male, but with paler and longer forewing. Forewing length: 49 mm; wingspan: 101 mm.

Geographical distribution. Wallacella guianensis is known from Trinidad, southern Venezuela, Guyana, and French Guiana ( Fig. 20 ).

Ethology. Specimens were attracted to light at dusk.

Host plant. Unknown.

Etymology. It is likely that Schaus (1940) proposed the specific name after the locality of the holotype specimen, Guyana.

Examined material (19 males, 1 female). Trinidad and Tobago. 3 males, Trinidad, Off Saunders Rd, Inniss Field , 50m, MV light: 17.V.1999, M. J. W. Cock leg. ( CGCM 35.217, 35.356 ( MJWC)) ; 1 male, Trinidad , F. Birch leg. ( NHMUK) . Venezuela: 1 male, Amazonas, Rio Mavaca Cp. 65°06’ W, 2°2’ N, 150 m, 16.–27.III.1989, D. Grimaldi leg., Exp. Phipps-Fudeci ( AMNH) . Guyana. 1 male ( Fig. 4 ; holotype), Bartica, Kartabo , 22.IX.1922 ( USNM) . French Guiana. 1 male, Rd. Paul Insard , 94 m, 5°17’02’’ N, 53°58’00’’ W: 6.X.2015, D. Herbin leg.

(CGCM 33.107; CGCM); 5 males, Rd. de la Montagne de Fer , 106 m 5°18’51’’ N, 53°32’00’’ W: 3.X.2015, D. Herbin, M. Laguerre & Felis leg. ( CGCM 32.951 , 32.997 , 33.340 , 33.398 , 33.526 ; CGCM) ; 1 male, Saül , Crique Limonade, 210 m, 4°32’42’’ N, 52°09’10’’ W: 19.X.2013 ( CGCM 32.943 ; CGCM) ; 1 male, Plateau des Mines , 5°20’42’’ N, 54°4’31’’ W: 4.X.2015, D. Herbin, M. Laguerre & Felis leg. ( CGCM 33.159 ; CGCM) ; 1 male, Rd. Belizon Km. 7, 67 m, 4°19’28’’ N, 52°20’7’’ W: 10.X.2015, D. Herbin & M. Laguerre leg. ( CGCM 33.392 ) ; 1 male, Rd. Apatou-Layons Km. 26, 99 m, 5°14’46’’ N, 54°11’52’’ W: 2.X.2013, D. Herbin, M. Laguerre & Felis leg. ( CGCM 29.958 ; CGCM) ; 1 male, Rd. Coralie , 46 m, 4°29’41’’ N, 52°23’41’’ W: 13.X.2013, D. Herbin leg. ( CGCM 30.042 ; CGCM) ; 1 male, Cariocou , 4°51’30’’ N, 52°17’ W: 4.X.1996, B. Hermier leg. ( CGCM 30.672 ; CGCM) ; 1 male, Grand-Santi , 100 m, 4°17’05’’ N, 54°21’06’’ W: 14–18.X.2017, Vincent, Lévêque & Barbut leg. ( CGCM 35.366 ; CGCM) ; 1 male, Rd. Kaw , 286 m, 4°32’57’’ N, 52°08’52’’ W: 27.X.2013, D. Herbin leg. ( CGCM 30.158 ; CGCM) ; 1 female ( MNHN) .

Remarks. In Trinidad and Tobago, this species has been recorded only in Trinidad. Inniss Field is a low altitude area of disturbed forest with scattered oil wells in the South of Trinidad.

Figures

FIGURE 20. Geographical distribution of Wallacella guianensis, comb. nov., and Gymelloxes juliusboosi, sp. nov., in Northern South America. Trinidad and Tobago inset.

FIGURES 1−6. Wallacella guianensis, comb. nov. 1−4, Male: 1a, dorsal view; 1b, ventral view (Trinidad, Off Saunders Rd, Inniss Field; CGCM 35.217; MJWC); 2, dorsal view (Trinidad, Off Saunders Rd, Inniss Field; CGCM 35.356; MJWC; lines: i—proximal antemedial, ii—distal antemedial, iii—proximal postmedial, iv—premarginal); 3, dorsal view (French Guiana; CGCM 33.107); 4, dorsal view, holotype of Phassus guianensis (USNM). 5, Female: dorsal view (MHNH). 6, Male wing venation (CGCM 30.158). Scale bar = 1 cm.

FIGURES 10−15. Wallacella guianensis, comb. nov. 10, Legs (CGCM 30.158). 11−12, Male abdomen (CGCM 35.217): 11, upper dorsal, lower ventral view; 12, tergum and sternum VII and VIII. 13, Male genitalia (CGCM 35.217): 13a, lateral view; 13b, anterior view; 13c, ventral view (pseudotegumen upwards). 14, Male abdomen (holotype), tergite and sternite VII and VIII. 15, Male genitalia (holotype), ventral view (unscaled). Scale bar = 1 mm.