Marimatha nigrofimbria ( Guenée 1852 ) Ferris & Lafontaine, 2010

Ferris, Clifford & Lafontaine, Donald, 2010, Review of the North American species of Marimatha Walker with descriptions of three new species (Lepidoptera, Noctuidae, Eustrotiinae) and the description of Pseudomarimatha flava (Noctuinae, Elaphriini), a new genus and species confused with Marimatha, ZooKeys 39 (39), pp. 117-135 : 121-123

Marimatha nigrofimbria ( Guenée 1852) , comb. n.

Figs 1, 2, 11, 18

Xanthoptera nigrofimbria Guenée in Boisduval and Guenée, 1852: 241, pl. 10, Fig. 12.

Thioptera nigrofimbria ( Franclemont, 1950) .

Type material. North America : lost. Neotype: Florida. USNM, here designated. There are two superficially similar species in eastern North America, so to ensure the stability of the name we designated a male labeled “ USA, Florida, Marion Co., W Anthony Rd, 1.4 mi W Anthony, 29°17'N, 82°08'W, 4 May 2000, T. S. Dickel” as neotype for Xanthoptera nigrofimbria Guenée, 1852 .

Other material examined and distribution. Approximately 2,400 specimens examined from the following states: Alabama, Arkansas, District of Columbia, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Massachusetts, Mississippi, Missouri, New Jersey, North Carolina, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia.

Diagnosis. Head with rounded frons. Male genitalia: valva with sharp apical point, irregular dorsal margin with large, tapered process at about 1/3 from apex; aedeagus with three clusters of cornuti, one toward base, one near apex, and a tight bundle of cornuti at apex. Female genitalia: ostial plate of female genitalia lyre-shaped with even slightly concave margin.

Description. Adult: Head – Front rounded without protuberance. Thorax – Yellow with brown flecks. Legs: Foreleg and middle leg, brown flecked with paler scales; hindleg yellow-tan flecked with brown scales. Wings: DFW lemon yellow with dark discal dot and usually a second dark spot in fold at 1/4 from wing base; occasionally a third spot below costa at ¼ from base; some pale orange shading may be present toward outer margin and on costa; terminal line and fringe blackish brown; DHW yellowish white with fuscous scaling toward wing margin and on terminal line; VFW yellowish buff, heavily infuscated with dark scales, except on well-defined pale band on inner margin; VHW pale buff, heavily flecked with brown scales, especially along anterior margin of wing. Female similar to male, but wings usually darker, especially hindwing. Male genitalia – Uncus: decurved, slender, expanded toward apex with acute tip. Valvae: symmetrical, basally broad, tapering to mid-length (at apex of sacculus), then narrowing to a pointed apex, without corona; dorsal margin irregular with triangular process at approximately 1/3 from apex; sacculus with blunt apex and uneven dorsal margin. Aedeagus: smoothly sclerotized; everted vesica tubular with a short stout spine at base, then patch of 5 robust spines near base, a distal patch of 6 large robust spines adjacent to a smaller patch of approximately 6 smaller spines of varying length. Female genitalia – Corpus bursae oval, tapered posteriorly with ductus seminalis at posterior end and ductus bursae entering corpus bursae on right near posterior end. Ductus bursae sinuate, with sclerotized longitudinal ridges, posterior ⅓ narrower than anterior ⅔ and gradually widening toward corpus bursae. Ostium bursae heavily sclerotized, lyre shaped, with sides constricted toward posterior end and with short ostial plate with slightly concave posterior margin.

Distribution and biology. Massachusetts westward through northern Ohio to Illinois and Oklahoma and southward to southern Florida and southernmost Texas. Flight season is from May to September in the northern part of the range and from March to November in the South. Reported larval hosts are Digitaria ischaemum (Schreb.) Shreb. ex Muhl. (Poaceae) , and Ipomoea sagittata Poir. (Convolvulaceae) .

Remarks. Marimatha nigrofimbria is replaced by a closely related undescribed species that occurs from southern Mexico (Chiapas) southward to Colombia. It will be treated in a revision of the genus Marimatha in Central America in preparation by J. B. Sullivan.