The Herminiinae as sister-group to the Aganainae
Kitching (1984: 215, 225) briefly surmised that there might be a sister-relationship between some Aganainae and the Herminiinae. Both groups typically have a prespiracular, if sometimes weak, counter-tympanal hood. This suggestion was discounted by Owada (1987: 8), and not revisited by Kitching & Rawlins (1998). Kitching & Rawlins dwelt more on a possible relationship of the aganaines to the Arctiidae and Lymantriidae; an association with the Arctiidae was supported by Lafontaine & Fibiger (2006), who also associated the Nolidae and Lymantriidae with this pairing.
However, the possibility resurfaced when the two groups were placed as sister-taxa in the molecular analyses of Mitchell (1998) and Mitchell et al. (2000). This result was again supported strongly in a more extensive analysis by Mitchell et al. (2006), who placed both groups as good families (see also Common (1990) and Nielsen et al. (1996)) within a clade that they termed the ‘LAQ’ (Lymantriidae, Arctiidae and ‘quadrifine’ Noctuidae) clade (see also p. 4).
This linkage of two otherwise contrasting groups is surprising. The Aganainae are large, robust, largely aposematic moths, both as larvae and as adults. They have been recorded as feeding solely on the foliage of Moraceae, Apocynaceae and Asclepiadaceae (Holloway, 1988; Common, 1990), plant families that produce toxic cardenolides. Specialism on these families is well known in the danaine Nymphalidae and occurs to a lesser extent in a few other moth genera (Holloway et al., 2001: 162). The Herminiinae are cryptic as adults, with larvae that feed mostly on dead plant material. Some taxa feed on living foliage of both higher and lower plants, but most feed on dead or withered foliage, more often that still attached to, or suspended within the plant rather than on the ground (Owada in Sugi, 1987).
Apart from the similarity mentioned above in the position of the counter-tympanal hood, there are no obvious synapomorphies that link the two groups exclusively. The labial palps and retinaculum of the male are different, as are characteristics of the male and female abdomens. The male eighth sternite in some herminiines such as Bocana, Ochrotrigona, Hadennia, Naarda Walker and some species of the Polypogon Schrank complex (p. 122) bears a single central corema as in aganaines but, as with the condition of the counter-tympanal hood, this may be homoplasious. A large central corema is seen also in the pantheine genus Trichosea Grote (Holloway, 1988: 303) and in Phyllodes Boisduval (Holloway, 2005: 262). Work in progress for this series on the Aediinae has revealed the presence of a single corema in Aedia Hübner. M. Owada (pers. comm.) has noted that in some Aganainae, e.g. in the genera Euplocia Hübner and Peridroma Walker, there are secondary sexual modifications of the male forewing costal area and venation that resemble those seen in some Herminiinae. Owada also noted that the antennae of male P. subfascia Walker are noded; they have a lens-shaped flattening in the dorsoventral plane at about two-thirds.
The larvae in most genera of both groups have a full complement of prolegs. The pupa in herminiines was stated by Kitching & Rawlins (1998) to have a waxy bloom as in some Catocalinae, and they suggested that a transverse row of indentations on the pupal metathorax might provide an autapomorphy for the aganaines.
The lack of strong support from morphology for the sister-group relationship indicated by molecular evidence is a conundrum that requires further investigation, as noted by Lafontaine & Fibiger (2006).
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