Phaeoura quernaria

Young, Catherine J., 2006, Molecular relationships of the Australian Ennominae (Lepidoptera: Geometridae) and implications for the phylogeny of the Geometridae from molecular and morphological data, Zootaxa 1264 (1), pp. 1-147 : 1-147

Phaeoura quernaria and Ennomos magnaria

P. quernaria (Oak Beauty) is the type species for the Nacophorini and E. magnaria (Maple Spanworm) is a member of the type genus of the Ennomini . Again the linking of these two species was very well supported by 28S D2 data (Fig. 10) and sequence divergence was a very low 0.3% (Appendix 7). This clade was also recovered with very high support from the combined molecular and morphological analysis (Fig. 17).

Heitzman (1985) linked the Azelinini , Nacophorini and Ennomos on the presence of pupal antennal tubercles. Forbes (1948) first noted the presence of this character in the Azelinini and the Nacophorini . P. quernaria is widely distributed in North America from Nova Scotia in Canada to Florida in the south of the USA ( McGuffin 1981). E. magnaria is also widely distributed from Nova Scotia in the north to Missouri in the south ( McGuffin 1987). Both species feed on a variety of deciduous trees.

Comparison of adult morphological features

—robust build; bipectinate with long rami (scaled in E. magnaria ); long, stout, apical sensilla chaeticae on rami; antennal terminal sensillum present in E. magnaria only; frons, rounded, non­protuberant, lacking basal shelf; projection dorsad to antenna, absent; areoles absent; foveae present in E. magnaria only; hind­tibia not dilated; two pairs of hind­tibial spurs in E. magnaria , only one pair in P. quernaria (but two pairs are present in the North American nacophorine Gabriola Taylor and a closely related North American nacophorine, Holochroa Hulst , also has only one pair of spurs).

Male genitalia

—simple, straight uncus; socii; gnathos with narrow arms; valvae, wide, complex in Phaeoura Hulst , simple in Ennomos Treitschke ; transtilla large; juxta, well­developed, extended posteriorly in Ennomos ; cristate hair absent; articulated lateral processes of the anellus absent; slender, straight aedeagi; discrete cornuti present in Ennomos only.

Female genitalia

—sclerotised ductus bursae; signum (weak) present in Ennomos only; bursa copulatrix, clearly differentiated.

Immature stages of these two species share few characters. The eggs of these two species are quite dissimilar. The eggs of P. quernaria are laid upright and have a row of nodules encircling the micropyle ( Engel 1908), whereas the eggs of E. magnaria (illustrated by Salkeld 1983) are laid flat, however the anterior pole is marked with a circle of cells with raised walls which may be homologous to the nodules in P. quernaria .

Larvae of these two species share the following characteristics: a granulated integument, truncated anal shield and moderately long paraprocts. Pupae are united by the presence of antennal tubercles and four pairs of cremastral setae. However well developed dorsal grooves and lateral grooves and exposed pro­thoracic spiracles are only present in Phaeoura . Unusually the Ennomos pupa is sometimes patterned with white, a characteristic more typical of the Geometrinae ( McGuffin 1981, 1987).

The larvae of Phaeoura and related genera possess some distinctive characteristics. An extra L seta, situated between L3 and L4, is present in Phaeoura and also the North American nacophorines Aethaloida McDunnough , Ceratonyx Guenée , Gabriola , Holochroa , Papago Rindge and Thyrinteina Möschler. In Gabriola , Holochroa and Phaeoura it is present on A1–6, whereas in Aethaloida , C. permagnaria Grossbeck and Thyrinteina it is present on A2–6. In Papago arizonensis Capps it is only present on A3–6 ( Heitzman 1985). McGuffin (1967) was the first to note this unusual seta in Phaeoura . He also remarked on its uniqueness in the Geometridae and coined the term LX for it. It is unclear whether this seta is sub­primary or secondary as second instar chaetotaxy for none of these species is published. Nevertheless its presence is an autapomorphy for most and perhaps all of Rindge’s Group One, North American Nacophorini ( Rindge 1983) . North American nacophorine larvae are also distinguished by the presence of multiple lateral setae (8–18) on the A6 proleg whereas in E. magnaria there are only 4 ( McGuffin 1987).

Again, as with E. excursaria and P. cognata in the previous section, this clade was afforded very high molecular support but with little corroboration from morphological characters; however the Nacophorini and Ennomini have been united on a seemingly weak synapomorphy, the presence of pupal antennal tubercles by Heitzman (1985). This again most likely demonstrates heterogeneity of morphology between closely related species.