Nacophorini, , McQuillan, 1985

Young, Catherine J., 2006, Descriptions of the eggs of some southern Australian Geometridae (Lepidoptera), Zootaxa 1287, pp. 1-294 : 1-294

Comment on Nacophorini

The Australian nacophorine eggs described in this study exemplify the diversity and heterogeneity of the group. No single character unifies the tribe as a whole; however, there are several groups within the tribe that are reasonably well defined. The eggs of Capusa and Palleopa are extremely similar and distinctive due to their upright orientation. Interestingly the eggs of the unplaced ennomine New Zealand Declana floccosa Walker are also laid upright either singly or in rows of up to 50 ( Kay 1982). Amelora eggs are singular due to the pronounced sculpturing of the chorion, conspicuously domed aeropyles with generally large openings and aeropyles distributed all over the egg surfaces. All other nacophorine eggs described here lack aeropyles at least on the top of the middle of the egg apart from Aphantes . However the eggs of Aphantes resemble closely those of Gastrina and Nisista due to the shared feature of double­ridged cell walls and the same general appearance. Androchela , Loweria and Dolabrossa form another group on the basis of egg shape and configuration, aeropyle shape and distribution and chorion texture. Two other major groupings are: Chlenias , Ciampa and Smyriode s; and, Fisera , Mnesampela , Paralaea , Plesanemma and Thalaina .

The eggs of a large proportion of Australian nacophorines require moistening before hatching will occur. This phenomenon was first recorded by McFarland (1973) who coined the term rain­hatched eggs to describe this behaviour. Taxa with this characteristic in this study were: Androchela milvaria , Dolabrossa amblopa , Chlenias ‘ zonaea ’ (late season eggs only), Ciampa arietaria , Smyriodes aplectaria , Smyriodes sp. , Cycloprorodes melanoxysta , Fisera , Mnesampela , Paralaea , Plesanemma , Thalaina , Stibaroma and Nisista notodontaria . McFarland (1973) also noted this feature in the Australian larentiine Chrysolarentia heliacaria Guenée. These taxa are all active in autumn between mid­ March and late May, usually a period of cooler weather and more consistent rainfall in south­eastern Australia. Eggs of these species generally reach maturity in a few weeks and the mature larvae are readily visible after this time. The larvae then appear to remain dormant and alive for sometimes up to several further weeks until they are cued, by moistening, to emerge. If this does not occur the neonate dies and the egg becomes desiccated. Summers in south­eastern Australia are dry and often prolonged and the onset of autumn rains is unpredictable. The inducement of hatching on moistening is likely to be an advantage to first instar larvae that would otherwise be subjected to a dry and hostile environment in the vulnerable early stages of life.

The only accounts of eggs of non­Australian nacophorines are superficial descriptions of the eggs of the American species Phaeoura cristifera Hulst ( Comstock 1959a) , P. quernaria J. E. Smith ( Engel 1908) , Ceratonyx permagnaria Grossbeck ( Comstock 1959b) , Aethaloida packardia Hulst ( Comstock 1963) (Comstock also provided line drawing of the eggs of these species) and P. kirkwoodi Rindge ( McGuffin 1967) . The eggs of P. mexicanaria Grote were also described by McGuffin (1967) as having similar eggs to the aforementioned Phaeoura species. Peterson (1968) described and illustrated the eggs of Holochroa dissociarius Hulst with low­magnification colour photographs. These species, apart from C. permagnaria , all belong to Group One Nacophorini sensu Rindge (1983) and occur mainly in North America. The eggs of these four genera bear litle resemblance to the Australian nacophorine eggs described above; however there are some similarities with the eggs of Capusa , Palleopa and Mictodoca . The eggs of these Nearctic species are remarkably similar in orientation and gross morphology. All eggs are laid upright and the general shape is bluntly ovoid with a circular anterior pole. Like Mictodoca the eggs of P. crisitifera have an abruptly truncated, smooth anterior pole encircled by a ridge of aeropyles that, together with longitudinally arranged cell walls on the lateral sides, form the beginning of lengthwise ribs that end abruptly. The eggs of C. permagnaria , P. quernaria and H. dissociaria also have the anterior pole encircled by a ring of conspicuous aeropyles. Little information on the oviposition behaviour of these species is available, however McGuffin (1981) noted that Phaeoura laid up to 480 eggs. In conclusion, because of the paucity of data recorded on nacophorine ova, it is difficult to draw any inferences about the relationship of Australian nacophorines with the world fauna on the basis of egg characters.