Ercta vittata (Fabricius, 1794)

Bernard Landry, 2016, Taxonomic revision of the Spilomelinae (Lepidoptera, Pyralidae s. l.) of the Galápagos Islands, Ecuador, Revue suisse de Zoologie 123 (2), pp. 315-399 : 337

Ercta vittata (Fabricius, 1794)

Figs 18 , 103 , 149

Phalaena vittata Fabricius, 1794: 217 . ‒ Roque-Albelo &

Landry, 2015.

Material examined: 7 ♂, 20 ♀, 2 of undetermined sex from the Galápagos Islands: – Genovesa: Bahía Darwin. – Marchena : [no precise locality]. – Pinta: Plaja Ibbeston [sic]; Cabo Ibbetson, 8 m elev[ation]., N 00° 32.819’, W 90° 44.229’; arid zone; ± 15 m elev.; ± 50 m elev.; 200 m elev. Deposited in BMNH, CDRS, and MHNG.

Diagnosis: This medium-sized species (20-23 mm in wingspan) is unique among the Galápagos lepidopteran fauna by virtue of its grey forewing adorned with a black and white longitudinal streak along midline from base of wing until a pair of superposed black dots with white centre at the end of the cell ( Fig. 18 ). There is also usually a thin black line from 2/3 dorsum to about 3/4 on costa and the termen is dotted black. The grey hindwing also has a black dotted termen and it also has a thin postmedian black line and two small black dots towards base medially.

Biology: The host plant and immatures are unknown (see Remarks below). Galápagos specimens have been collected in March and April mostly at low elevations, up to 200 m, only on three islands that were never inhabited, but which (at least Pinta) suffered degradations from introduced goats and the elimination of the giant tortoises.

Distribution: Described from ‘Americae meridionalis Insulis’ (Islands in South America) and widespread across the West Indies and South America from Paraguay and north (BMNH specimens), this species occurs as well in Costa Rica (www.boldsystems.org) and Florida, USA ( Heppner, 2003; Patterson et al., 2015). From the Galápagos I have seen specimens only from Genovesa, Marchena , and Pinta.

Remarks: I have identified Galápagos specimens by comparison with specimens in the BMNH, including a dissected male. The larva has been recorded to feed on Euclasta torquillalis and Atomopteryx torquillalis ( Heppner, 2003; Robinson et al., 2014), but this species name refers to a moth described by Möschler (1890) and a synonym of Ercta vittata (see Nuss et al., 2016).

Figures

Figs 17 - 24. Neotropical specimens of Spilomelinae, size not to scale. (17) Diaphania nitidalis ♀, Brazil, Bahía, Camacan, Res. Serra Bonita, 800 m, 8. iv. 2011, MHNG. (18) Ercta vittata ♂, Galápagos, Marchena, 12. iii. 1992, MHNG. (19) Herpetogramma bipunctalis ♂, Galápagos, Santa Cruz, CDRS, Barranco, 20 m, 30. iv. 2002, MHNG. (20, 21) Herpetogramma phaeopteralis. (20) ♂, Galápagos, Isabela, NE slope Alcedo, Los Guayabillos camp, 869 m, 2. iv. 2004, MHNG. (21) ♀, Galápagos, San Cristóbal, near La Loberia, sea level, 24. ii. 2005, MHNG. (22, 23) Hymenia perspectalis. (22) ♀, Galápagos, Santa Cruz, Los Gemelos, 4. v. 2002, MHNG. (23) ♀, same locality, 27. v. 1992, MHNG. (24) Lineodes integra ♂, Pinta, Cabo Ibbetson, 8 m, MHNG.

Figs 101 - 103. Male genitalia of Spilomelinae, a and b from same slides, but not to scale, (a) showing the genitalia without phallus and b, the phallus. (101) Diaphania indica: slide MHNG-ENTO- 8673, Mozambique, Makulane. (102) Diaphania nitidalis: slide BL 1810, Galápagos, Santa Cruz (CAS). (103) Ercta vittata: slide MHNG-ENTO- 9028, Galápagos, Pinta (MHNG).

Figs 148 - 152. Female genitalia of Neotropical Spilomelinae, not to scale. (148) Diaphania nitidalis: slide MHNG-ENTO- 8960, French Guiana. (149) Ercta vittata: slide MHNG-ENTO- 9029, Galápagos, Marchena (MHNG). (150) Herpetogramma bipunctalis: slide MHNG-ENTO- 8685, Galápagos, Isabela. (151) H. phaeopteralis: slide MHNG-ENTO- 8684, Galápagos, Fernandina. (152) Hymenia perspectalis: slide MHNG-ENTO- 9000, Galápagos, Santa Cruz.