Sematuridae, Nothus (= Sematura).

Many of the thirty-five Neotropical species of these delicately built moths are easily confused with saturnians because of their large size (WS 75 mm) and similar brown markings (fig. 10.5c). They also have tails extending from the hind wing like some Saturniidae, but these are spatulate and with a conspicuous eyespot in the rounded, apical portion unlike any in that family- Their fine, hairlike antennae, rather than the feathery elaborations, also clearly distinguish them. They are actually more closely related to the day-flying rainbow moths (Uraniidae) but are noctur-nally active. They often come to rest with the fore and hind wings separated, the latter more or less rolled around the abdomen.

Virtually nothing is published regarding the early stages or biology of this genus.

Mimetic Moths

Along with several kinds of butterflies, several related groups of slow-flying, diurnal, rubbery-bodied moths are brightly colored and participate in Müllerian mimicry complexes. External resemblances among species in the same pattern series may be so great that even specimens in hand are difficult to distinguish. Certain characteristics of the veining in the wings (often to be seen only with a magnifying lens) will separate the families. As an aid to the reader's understanding of the differences, they are summarized here, prior to the individual discussions of the families.

Smoky moths (Zygaenidae) are the easiest to separate because of the presence of a vein running lengthwise through the middle of the large, central cells in both fore and hind wing. This is a vestigial condition, revealing the family's comparatively primitive phylogenetic position.

The remaining groups segregate primarily on the basis of the branching patterns of the anteriormost set of veins in the hind wing. In the wasp moths (Arctiidae, Ctenuchinae), this vein appears to have a single fork (bipartite) due to the complete absence of the normally present first vein

(subcosta). In all the remaining groups, this vein is tripartite, with the first vein being completely separate, even at its base, in the dioptid moths (Dioptidae). Additionally, in this family, the branching points of the outermost forked veins in the hind wing occur near the wing edge, beyond the outermost part of the large central cell. These veins are mostly separate basally, only a short length being fused at a point near to or before the middle of the cell bordering it behind, in the flag moths (Arctiidae, Pericopinae).

In the tiger moths (Arctiidae, Arctiinae), forester moths (Agaristidae), and giant day-flying moths (Castniidae), the fusion of these two anterior veins is complete almost for the entire distance along the length of the cell in all, and they are distinguished by other venational features, for example, the closeness of the origin of the next vein in the hind wing (following the anterior triple vein just referred to) to its neighbor behind. It is close in the tiger moths, more widely separated (equidistant from the vein preceding) in the forester moths and giant day-flying moths. The latter two families are distinguished by the large central cell of the hind wing which is open (i.e., not closed off by a cross vein). Also, all the veins tend to run parallel to each other in the latter, while many are divergent in the former. Both have clubbed antennae, much more so in the Castniidae.

In other families such as the owlet moths (Noctuidae), sphingids (Sphingi-dae), pyralids (Pyralidae), and measuring worm moths (Geometridae), in which noc-turnalism and cryptic wing patterns are the rule, a few mimetic types occur, but these are clearly separable by gross features mentioned in the discussions of these groups. It should be stressed also that all the members of the families placed in the "mimetic moth" category above are not diurnal and highly colored. Many tiger moths, for example, are drably or cryptically marked and fly by night.

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