The caterpillar (figured on Plate [131], Fig. 2, after Sich) is brownish inclining to ochreous; a dark brownish line along the middle of the back, and a series of brownish diamond-shaped marks most distinct on the back of the middle rings; a line of blackish marks along the sides shows up in the paler examples. Sometimes the general colour is dark reddish brown, freckled with dark brown; but in all cases the underside is paler than the upper, and is striped and lined with dark and pale brown.
It feeds on hawthorn, birch, elm, hazel, bilberry, heather, etc., from July to May.
The moth is out in June and July, and specimens of a second generation have been reared in September. Generally common throughout the British Isles.
Great Oak Beauty (Boarmia roboraria).
Fig. 18.
Caterpillar of Great Oak Beauty.
(Photo by "A. Forester".)
The fine Boarmid moth shown on Plate [135], Fig. 2, has all the typical markings well defined. Occasionally the black cross lines are more distinct, but sometimes they are more or less absent, or obscured. An almost black specimen is mentioned by Barrett as taken in the Reading district, Berkshire; and the same author states that a black example was captured in the Midlands about the year 1887, but no other specimen was observed until 1893, when a female was obtained, and from eggs deposited smoky black moths were reared.
The caterpillar is very like an oak twig in shape, especially when in repose. (See Fig. 18.) In colour it is reddish brown, inclining to ochreous brown; brownish grey on the humps on rings 5 and 11, and on the skin folds. It feeds on oak during the autumn, and, after hibernation, in the spring. The moth is out in June and July, and may be found on oak trees rather high up the trunks. When on the wing at night it will visit the sugar patch.