Gymelloxes juliusboosi, 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 : 187-189

Gymelloxes juliusboosi , sp. nov.

( Figs 7a, 7b, 8a, 8b, 9a, 9b , 16, 17, 18, 19a, 19b, 19c, 19d )

= Aepytus terea (Schaus) : Cock (2003: 50)

= Gymelloxes terea (Schaus) : Cock (2017: 4)

Diagnosis. Gymelloxes juliusboosi , sp. nov., can be distinguished from G. terea and G. prosopus only by examination of the sternite VII and VIII and the male genitalia. In G. juliusboosi , sp. nov., the sternite VII is hourglass shaped and the sternite VIII is membranous, while in all its congeneric species the former structure is rectangular and the second is sclerotized, respectively. The unique, conspicuous, mesal process of the posterior margin of the saccus is diagnostic for G. juliusboosi , sp. nov., while in G. terea and G. prosopus , the homologous structure is represented by two short, apically flat, and peg-like projections lateral to the median ( Grehan & Mielke 2017).

Description. Male ( Figs 7a, 7b, 8a, 8b ). Head. Antenna bipectinate with ~32 antenomeres; dorsal surface with lamellate scales, dorsal apex with tuft of longer narrow scales; flagellum inner surface carpeted with sensilla trichodea, outer surface with scattered sensilla chaetica. Eyes prominent, bulging from head. Head vestiture with erect orangish-brown scales over vertex, frons, and mouthparts. Intra antenna-ocular scales short, indistinct from vertex scales. Labial palp short, covering scales short and reddish brown.

Thorax. Coloured as the head. Legs. Epiphysis and arolium absent. Forewing length: 18–24 mm; wingspan:

38–49 mm. Forewing dorsally. Elongated, tornus shallow; costal margin straight, slightly concave mid-length, apex blunt, outer margin convex, inner margin slightly convex. Ground colour pale yellowish-brown to light brown; stigma light yellow; when darker markings of light grey present, then basal area distinct greyish-brown concolours to postdiscal, premarginal bands and central patch proximately greyish-brown, and about six greyish-black bands between coastal margin and Sc/Rs. Hindwing dorsally. Orangish-brown, lighter than forewing. Forewing and hindwing ventrally. Uniformly coloured, light orangish-brown, but paler than forewing and without markings.

Abdomen ( Figs 16–18 ). Dorsally as the thorax, ventrally lighter; tip of the abdomen with longer scales. Tergum VII slightly narrower and longer than tergum VI. Tergum VIII with convex posterior margin. Sternum VII rectangular and constricted at mid-length. Sternum VIII membranous (see remarks).

Male genitalia ( Figs 19a, 19b, 19c, 19d ). Tegumen (= intermediate plate) slightly distinct, but fused to pseudotegumen and projected dorso-posteriorly to form the digitiform process with the tergal lobes and the pseudotegumen. Saccus U-shaped, projected and tapered anteriorly; anterior margin broad, posterior and lateral margins projecting ventral to form a vertical wall or shelf with a single conspicuous mesal process, apically indented. Tergal lobes sclerotized, digitiform, projected posteriorly with rounded apex, and fused to pseudotegumen. Pseudotegumen rectangular; dorsal projection as for the tegumen; ventrally fused, curved ventrally with ventral apex strongly sclerotized. Valva spatulate, inner surface densely setose, apex rounded. Fultura inferior (= juxta) sclerotized, rectangular, wider than long, lateral and posterior margins slightly concave. Fultura superior (= trulleum) partially sclerotized in two rows of two irregular shaped blotches. Phallus membranous except for distal region covered with numerous spicules.

Female ( Figs 9a, 9b ). Examined only as a photograph. Same pattern as the male, but paler and longer forewing. Forewing length: 47 mm; wingspan: 102 mm.

Geographical distribution. Gymelloxes juliusboosi , sp. nov., is only known from Trinidad and Tobago islands ( Fig. 20 ).

Ethology. All specimens at the type locality were attracted to light at dusk.

Host plant. Unknown.

Etymology. Gymelloxes juliusboosi , sp. nov., is dedicated to the late Julius O. Boos ( Boos 2010), who shared his deep knowledge of the Lepidoptera and ecology of Trinidad with the third author.

Type material. Holotype male with the following labels (separated by forward slashes): / HOLOTYPUS, Gymelloxes juliusboosi C. Mielke, Grehan & Cock des. 2018/ Aepytus (Gymelloxes) terea Schaus male, Det. M.J.W. Cock 2001/ Trinidad, W.I., Off Saunders Road, Inniss Field, c. 50 m, At beginning of track to dam, MV light, dusk- 22.10h, 17.v.1999, M.J.W. Cock [leg.]/ Illustrated in Cock (2003), Living World. Plate 1.42/ ( NHMUK). Figs 7a, 7b .

Paratypes (in total 3 males and 1 female). All Trinidad and Tobago . 1 male, same data as the holotype (35.247 Col. C. Mielke; CGCM)) ; 1 male, Trinidad, St. George Co., Curepe , MVL: 22.–31.V.1982, M. J. W. Cock leg. ( CMNH) ; 1 female, Trinidad, Morne Bleu, Textel Installation : 5.V.1989, R. G. Brown & T. Cassie leg. ( UWIZM CABI.3927) ; 1 male, Tobago, Charlotteville , at light: 14.–18.VI.1999, R. Hammond leg. ( UWIZM) .

Remarks. The membranous sternite VIII present in Gymelloxes juliusboosi , sp. nov., is an apomorphy, since all other Gymelloxes spp. examined show a sclerotized and undifferentiated sternite VIII.

The newly described species is recorded from Tobago ( Cock 2017) as well as Trinidad. Records are from both the north and south of Trinidad, mostly from forested situations up to 700 m (Morne Bleu), but one record is from a suburban area (Curepe).

Figures

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

FIGURES 7−9. Gymelloxes juliusboosi sp. nov. 7, Male holotype (enlarged 2x): 7a, dorsal view; 7b, ventral view (NHMUK). 8, Male paratype (CGCM 35.247; enlarged 2x): 8a, dorsal view; 8b, ventral view (NHMUK). 9, Female paratype: 9a, dorsal view; 9b, ventral view (UWIZM). Scale bar = 1 cm.

FIGURES 16−19. Gymelloxes juliusboosi, sp. nov. 16−17, Male abdomen paratype (CGCM 35.247): 16, upper dorsal, lower ventral view; 17, tergite and sternite VII and VIII; 18, lateral view. 19, Male genitalia paratype (CGCM 35.247): 19a, ventral view (pseudotegumen upwards); 19b, ventral view; 19c, anterior view; 19d, lateral view. Scale bar = 1 mm.