II. THE NOTODONTINA. ' 95 



DECLANA ATEONIVEA, Walk. 

 (Dctunda atronivea, Walk., Suppl. ii. 619. Chlenias (?) manxifera, Fereday, Trans. N. Z. Inst. xii. (1879), 



268, pi. ix 1. Dctunda atronivea, Meyr., ib. xvi. 101.) 

 (Plate X., fig. 33 2 , 34 2 ; Plate III., fig. 18, larva.) 



This very handsome and conspicuous insect appears to be restricted to the North 

 Island, where it is rather rare. It has occurred at Wellington, Otaki, and Napier. 



The expansion of the wings of the male is If inches, of the female nearly 2 inches. The fore- 

 wings are brilliant shining white, with numerous black markings ; these consist chiefly of three 

 irregular branching transverse bands, and a series of wedge-shaped spots on the terrnen ; the 

 larger markings are brownish in the centre. The hind-wings are dark grey, becoming almost 

 black on the termen, with a fine wavy transverse black line. 



This species varies considerably in the size and shape of the black markings on 

 the fore-wings, which are often slightly different on the opposite sides, in the same 

 specimen. 



The eggs of this moth are oval in shape, slightly roughened on the surface and 

 light blue in colour. They are deposited towards the end of October. The young larva 

 escapes by gnawing a hole out of the side. 



"When first hatched it is dull brownish-black, with creamy- white lateral lines and prolegs ; 

 the head is reddish. It feeds on Panax arborea. After the first moult the lateral lines become 

 much wider, especially towards the head. After the second moult the two dorsal tubercles are 

 fully developed, the thoracic segments much swollen and flattened above, the latter bearing traces 

 of the black markings of the full-grown larva. After the third moult the larva becomes a dark 

 brownish colour inclining to chocolate on the dorsal surface. The characteristic markings on the 

 penultimate and anal segments of the adult larva now appear, and the dorsal tubercles are yellowish 

 in colour ; the extra prolegs are very small, and are visible as wart-like appendages on the lower 

 surface of the tenth segment. 



The full-grown caterpillar is a remarkable-looking animal. The head is very small ; the first 

 three segments of the body are enormously swollen and flattened above, the flattened portions being 

 white, with several small black ring-shaped markings ; there is a pair of large yellowish tubercles 

 on the dorsal surface of the seventh segment, and two smaller ones on the tenth and eleventh 

 segments ; the larva is much stouter towards the posterior extremity, especially behind the ninth 

 segment ; the penultimate segment is furnished with a large creamy-white ridge, starting on the 

 back and proceeding downwards and forwards ; the extra pair of prolegs is small and only occa- 

 sionally used in walking. The general colour of the larva is brownish- or blackish-green ; the 

 tenth and eleventh segments are generally darker, and there are many fine parallel lines of 

 darker colouring on the central portions of the larva ; the whole insect is also speckled with 

 black ; the spiracles are red. The larva varies a good deal in colour, but its peculiar structure 

 will at once distinguish it from any other. 



These larvae often coil themselves up when at rest, clinging firmly with their large 

 prolegs to their food-plant. Whilst thus engaged they have a very remarkable 

 appearance. I have not yet ascertained the precise object of the peculiar shape and 

 coloration of this caterpillar. It appears to resemble very closely a lichen-covered twig, 

 but I suspect in this case there is something more special aimed at. 



In connection with this subject, it is noteworthy that the flattened extremities of the 

 elytra of the beetle, Ectopsis ferrugalis, closely resemble in both shape and colour the 

 remarkable anterior segments of the larva of D. atronivea. As both insects feed on the 

 same plant, and thus exist under very similar conditions, it is highly probable that the 

 peculiarities have been independently acquired in each species for similar purposes. 



The pupa is enclosed in a light cocoon amongst dead leaves, &c., on the surface of 

 the ground. 



