''Idaea dilutaria'', also called the silky wave, is a

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

of the family Geometridae. It is found in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. The species has a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of ...

of 20–22 mm.Recognizable by its strongly silky gloss, the absence of costal colouration (the costal margin has merely a sparse dusting of dark scales), the unmarked distal margin and fringe.The ground-colour is yellowish-tinted the discal dots are minute and there are no terminal lines.The other lines are generally all of approximately equal expression, sometimes the postmedian a little stronger, sometimes the median of the forewing weak.The underside is similar, the postmedian line often a little stronger, theantemedian and sometimes the median of the forewing obsolete. The males antennal ciliation is short and even.Prout, L. B. (1912–16). Geometridae. In A. Seitz (ed.) ''The Macrolepidoptera of the World''. The Palaearctic Geometridae, 4. 479 pp. Alfred Kernen, Stuttgar
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The adults fly in one generation in July . The larvae feed on '' Helianthemum nummularium''.

Notes

#''The flight season refers to the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

. This may vary in other parts of the range.''

References

External links

Silky Wave at UK MothsFauna EuropaeaLepiforum.de
Sterrhini Moths of Europe Moths described in 1799 Taxa named by Jacob Hübner {{Sterrhinae-stub