The aestival brood is much smaller than the vernal brood.
2.
There are two distinct forms, an aestival ( summer ) and autumnal form.
3.
The forewing of the aestival form is white, that of the autumnal form golden yellow.
4.
There are two forms, an aestival ( summer ) and an autumnal form, which are distinct in colour-pattern.
5.
Adults of the autumnal form are on wing in October and November, while the aestival form is on wing in July.
6.
But if you prefer " aesthetic " to " esthetic ", then you may also prefer the spelling " Aestival Festival ".
7.
The wingspan is 6.4-7.2 mm for the autumnal form and about 5.7 mm for the aestival ( summer ) form.
8.
The aestival form has an ochre-brown forewing marked distinctly with a yellowish costal blotch, while the autumnal form has darker forewing with no distinct costal mark.
9.
The wingspan is 6.1 9 mm for the vernal ( spring ) form and 5.7-6.9 mm for the aestival ( summer ) form.
10.
There are two seasonal colour forms, an autumnal form with a whitish, triangular costal blotch on the fore wing and an aestival form with a brassy-yellow costal blotch.
