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SUBFAMILY
EUSTROTIINAE |
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Ueda (1984, 1987) studied the representatives from Japan and Taiwan of the core genera now included in the Eustrotiinae. In the process, he placed the type genus, Eustrotia Hübner (type species uncula Clerck, Europe), and Lithacodia Hübner (type species bellicula Hübner, U.S.A.) as synonyms of Deltote Reichenbach (type species argentula Hübner, Europe). He also considered two genera, Neustrotia Sugi and Maliattha Walker, with no obvious synapomorphies with the core group. Poole (1989) retained Eustrotia and Lithacodia as distinct, and Edwards in Nielsen et al. (1996) also retained Eustrotia. Neustrotia subsequently proved to be a synonym of Chorsia Walker, an expanded concept of which brought together taxa previously placed in the traditional Amphipyrinae (Aeologramma Strand), Acontiinae (Neustrotia) and Ophiderinae (Chorsia), as treated under the sixth miscellaneous sequence of genera in Holloway (2005: 405). He treated 18 species from Borneo, and further Oriental taxa have been located that are misplaced in the New World genus Hyperstrotia Hampson, as discussed on p. 191. The biology is unusual, reviewed by Holloway (2005), as the final instar does not feed; only the first pair of larval prolegs is strongly reduced. The classificatory position of Chorsia is unclear, but the Oriental genus Microxyla Sugi is also related (Holloway, 2005). The group appears to be associated with the Leguminosae. Maliattha is described below, as it (and the related Hiccoda Moore) is best retained in the concept of Eustrotiinae advocated by Fibiger & Lafontaine (2005), but no clear synapomorphies with the core group are evident apart possibly from the forewing facies feature discussed below. Vein M2 in the hindwing is only slightly weaker than M3 in some genera, but absent from others. When present, it arises from the cell separate from M3 in the trifine position. This concept of the subfamily is narrower than that of Kitching & Rawlins (1998), who also included the Aventiinae (p. 81) and Eublemminae (p. 159) in their Eustrotiinae, thereby combining together noctuid groups from the major quadrifine and trifine clades of Lafontaine & Fibiger (2006). Ueda (1984) defined the core group on the basis of features of the male genitalia, including the musculature. The phragma lobes of the second abdominal tergite are not evident. The male eighth sternite is unmodified, but the tergite has short, splayed apodemes. The apex of the aedeagus (phallus of Ueda) is strongly downcurved in all the genera, and its distal half is membranous dorsally. The constituent genera are also defined primarily on features of the male genitalia (though Ueda (pers. comm.) is currently assessing features of the thoraco-abdominal junction). . It is therefore unfortunate that the only Bornean species potentially a member of this group is represented by a single female. It is discussed below, placed tentatively in Koyaga Ueda. Most of the species in the core group appear to share a characteristic forewing feature where the orbicular stigma is accompanied by a similar marking, possibly a claviform stigma, set obliquely distad to it posteriorly, often approximately the same size and shape, such that the orbicular appears doubled, the two markings together being more extensive than the generally B-shaped reniform. The feature is also seen in the Japanese Maliattha species with the most plesiomorphic forewing facies, M. rosacea Leech, illustrated by Ueda (1987). In most other true noctuids the claviform stigma is somewhere between basal to posterior from the orbicular, rather than distinctly distal. The hindwing never reproduces elements of the forewing pattern. The genus Hypercodia Hampson may belong to the core group, but material is limited to two males and a female with rather worn forewings, so the facies features are obscure. The male and female genitalia have some characteristics in common with the core group as discussed on p. 64. The genus Cretonia Walker is also associated tentatively with Maliattha and Hiccoda, sharing some genitalia features with them, and lacking features characteristic of the Aventiinae. Eulocastra Butler is also included, following Fibiger & Hacker (2005). An even more tentative placement here, based on abdominal features, is that of Naranga Moore. The larvae of the Deltote group lack the first pair of prolegs and have those on A4 reduced (Bretherton et al., 1983). They feed on grasses, as do those of Maliattha and Hiccoda (see below). Poole (1989) listed under Eustrotia a taxon E. labuana Swinhoe, following an entry to this effect in the BMNH card index, and citing original description of the species (Trans. ent. Soc. Lond. 1904: 139) in the acontiine genus Agrophila Boisduval. However, this citation was applied by Holloway (2003: 23) to Ctenane labuana Swinhoe, the type species of its genus, transferring the genus from Lithosiinae to Nolinae. Watson, Fletcher & Nye (1980) listed the type species of Ctenane Swinhoe as Ctenane labuana Swinhoe, with genus and species described as new in the same publication (1905, Ann. Mag. nat. Hist. (7) 15: 497). This does indeed refer to C. labuana nov., with no mention of the 1904 taxon. Examination of the type specimen of C. labuana showed it to bear two type labels in Swinhoe’s hand, one for Agrophila labuana, and the other for Ctenane labuana, despite the fact that the descriptions in the two publications give the impression of different species with different sizes! In the second publication, Swinhoe stated in a footnote to the generic description that he owed “the diagnosis of this genus to Sir George Hampson”. |
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