Omiodes monogona Meyrick, 1888

Yepishin, Viktor & Govorun, Oleksandr, 2024, A recent encounter with Omiodes monogona Meyrick, 1888 (Crambidae: Spilomelinae) - an interesting snout moth endemic to Hawaii, Zootaxa 5406 (2), pp. 397-400 : 397

The original description of Omiodes monogona Meyrick, 1888

was based on one female from Hawaii without specifying the exact island where it was collected. Zimmerman (1958: 108–109) discussed its biology, parasitoids, and included descriptions of preimaginal stages and figures of genitalia of both sexes.

Material examined: 15♂, 7♀ USA, The Hawaii archipelago, Maui Island, Kula village , 20.7353N 156.3323W, 950 m, at light, 12.xii.2015 – ii.2016, leg. O. Govorun; prep. no. ♂ 746.23s, ♂ 757.23s, ♂ 758.23g, ♀ 747.23g, ♀ 748.23s, ♀ 749.23g, ♀ 750.23g V. Yepishin, deposited in the Institute for Evolutionary Ecology (Kyiv) and the private collection of the first author. Adults were collected near artificial light sources from mid-December to February in the southern vicinity of Kula village ( Figs 4–5 ). Nearby, we observed the possible food plant of the caterpillars, Erythrina sandwicensis O.Deg. ( Fabaceae ) cited by Zimmerman (1958: 108 (as E. monosperma Gaudich. )) as the principal and native hostplant.

Adult ( Figs 1, 2 ): wingspan 23–26mm, sexual dimorphism is not expressed, the female antenna is slightly thinner than in the male, other head structures are the same in both sexes ( Figs 3a, b ).

Male genitalia ( Figs 6a–e, 7 ): uncus very long, thin, uncus base subtrapezoidal, expanded at apex, densely covered with short setae; tegumen about 1.7× shorter than uncus; valva large, blade-like expanded, rounded protrusion on costal edge, base of costa slightly sclerotized, cucullus not sclerotized; almost in middle of valva a transverse sclerotized lintel bears triangular-shaped fibula with an apical tooth adjacent to sacculus and directed towards valva; coremata or “hair tuft” very wide, not longer than the valva (not figured); sacculus 2× shorter than valva, sclerotized; juxta flat oblong with constriction in middle, slightly bifurcated distally; vinculum subtriangular; phallus cylindrical, fusiform, oblong 1.2× shorter than valva with one thin, long cornutus 1.6× shorter than phallus.

Female genitalia ( Fig. 8 ): papillae anales narrow, subrectangular, covered with short setae; posterior and anterior apophyses almost straight, slightly curved at base; anterior apophyses 2× longer than posterior ones; segment VIII same length as posterior apophyses, posterior margin equal, anterior margin of sternum VIII with wide V-shaped emargination; antrum not pronounced, cylindrical slightly expanded; colliculum cylindrical strongly sclerotized; ductus seminalis thin, departing near colliculum; ductus bursae long, thin, about 3× longer than corpus bursae, signa absent.

Distribution: endemic to Hawaii; Hawaii, Maui, Oahu, Kauai, Molokai and Lanai Islands ( Zimmerman 1958; iNaturalist 2024).

Figures

FIGURES 1–5. Adults of Omiodes monogona and their habitat. 1. Male. 2. Female. 3. Male head: a. lateral view, b. upperside view. 4–5. Habitat near the collection site.

FIGURES 6–8. Genitalia of Omiodes monogona. 6–7. Male genitalia and abdominal structures, prep. no. ♂746.23s: a. genitalia, ventral view, phallus separate, b. phallus, c. tympanal organ, d. segment 8 sternite, e. segment 8 tergite. 7. Juxta, enlarged, prep. no. ♂757.23s. 8. Female genitalia, ♀748.23s.