Magulacra, Davis & Gentili-Poole & Mitter, 2008

Davis, Steve R., Gentili-Poole, Patricia & Mitter, Charles, 2008, A revision of the Cossulinae of Costa Rica and cladistic analysis of the world species (Lepidoptera: Cossidae), Zoological Journal of the Linnean Society 154 (2), pp. 222-277 : 258-259

MAGULACRA GEN. NOV.

Type species: Hemipecten niveogrisea Schaus, 1905 (by present designation).

Description

Male: Forewing length: 8–20 mm.

Female: Forewing length: 17–18 mm.

Head: Antenna with inner serrate rami reduced in size; scales on antennal shaft cream to light brown; labial palpus cream to light brown ventrally, and light brown to dark or rusty-brown dorsally; frons creamy white to pale brown or dark brown; vertex same as frons.

Thorax: Forewing with terminal patch at distal area adjacent to termen. Wing venation variable; R 2 of forewing most often fused and forked with R 3, sometimes separate; R 3 or R 2+3 of forewing most often separate from R 4, sometimes fused and forked with R 5; R 4 or R 3+4 of forewing most often separate from R 5.

Abdomen: Cream and light brown to rusty pale-brown and dark or rusty-brown dorsally; cream and light brown to dark brown ventrally.

Male genitalia: Valva small, with a blunt, truncate apical region; saccular process spiniform, with spiniform projection variable in size and length; spines can be rather small with acute simple or trifid apices, or can be somewhat large and project from the sacculus like horns; base of costa with basal lobe most often absent, or if present, then reduced and weakly pronounced. Uncus mostly shallowly bifid, elongate and fairly slender, protruding beyond valvae as a result of their shortened length; setal patches mostly restricted to terminus of uncus. Invagination between tergite 9 of genital capsule and uncus most often reduced or absent, but in one undescribed species it is lobe-shaped and curving around base of gnathos. Gnathos bridge mostly elongate, slender and flattened; arms long and slender, not protruding beyond bridge, and recurving into tergite 9. Anal tube mostly sclerotized. Juxta process variable, from elongate, digitiform, and free from valva to short and mostly fused to valva; processes mostly membranous, but can be lightly sclerotized. Aedoeagus with dorsal crest normally present, reduced in size, but can be absent; coecum reduced to nearly absent; rostellum digitiform and slender, with apex acute and rounded; vesica with spines absent, but when present, spines minute and setiform.

Female genitalia: Sternite 8 developed, sclerotized and triangular, with sides slightly concave. Intersegmental membrane between abdominal sternites 7 and 8 developed, lightly sclerotized, sculptured with cuticular wrinkles and folds, and forming two loosely compressed lobes on either side of the ostium. Ductus bursae rather elongate and straight, and nearly uniform in width along entire length. Corpus bursae small and spherical.

Etymology: Derived from the latin word ‘magulum’ meaning ‘jaw’. Magulacra refers to the gnathos, and with the suffix ‘-cra’, meaning ‘thin’, refers to the slender form of the gnathos.

Discussion: Most species within Magulacra can be recognized by the presence of a simple, unmarked terminal patch on the forewing, in contrast to the characteristic terminal patch of Cossula , which contains a distinct pattern composed of thick, curved lines. However, one species of Magulacra , M. notodontoides , possesses a faded terminal patch that is relatively indistinct from the rest of the forewing. Also, M. cleptes and M. albimacula have a very distinct terminal patch similar to that present in Cossula . The forewings of most species within Magulacra generally possess little pattern and instead exhibit a relatively uniform colour. The exceptions here are three undescribed species whose forewings are marked with dark spots and transverse striae.

Magulacra is characterized by several specializations of the male genitalia. The most significant synapomorphy is the reduced to nearly absent sclerotized fold on the tegumen ( Fig. 97 ). In all other cossuline genera, this flap is well developed. The male valvae are characteristically reduced in length in Magulacra , not reaching the apex of the uncus. The arms of the gnathos are weak, very slender and elongate, and typically form a long, slender bridge when fused, which is typically flattened and divergent (from the uncus). The arms also are recurved into the genital capsule more so than in all other cossuline genera, where they often protrude beyond the tegumen.

Figures

Figures 95–100. Male genitalia, lateral view of genital capsule: 95, Spinulata quasivinnea; 96, Simplicivalva ampliophilobia; 97, Magulacra niveogrisea; 98, Cossula arpi; 99, Cossula buspina; 100, Cossula coerulescens. Scale bar = 1.0 mm.