THE CANADIAN ENTOMOLOGIST, 77 



In " Entomologica Americana," Vol. I., p. 117, Dr. H G. Dyar de- 

 scribes the preparatory stages of Arctia proxivia; hence it would be useless 

 to refer again to the larval stages of this species, did not the rearing in 

 vast numbers reveal similar flexible and pliant endowments for the larvae, 

 as it did in regard to the imagoes. 



The larvae in their earliest stages change their original whitish ground- 

 colour gradually to light yellow-brown or dull amber, and during their 

 growth toward maturity, to dull or dusky orange and reddish-brown. 



At third stage brown pigment accumulating at first patch-like, mostly 

 near the bases of warts I. and II., forms a broad, brown subdorsal sphere 

 or band, in which the two warts are situated. The dull, dark coffee-brown 

 colour, spreading by degrees along the segmental folds to ventral region, 

 increases in extent and deeper shade with the growth of the larvae. After 

 fourth moult (fifth stage) the larger, central part of segments from dorsum 

 toward stigmatal line and often beyond it, appears deep velvety-black ; 

 the dull, greasy brown colour spreading subventrally from the segmental 

 folds, sometimes at this stage overcomes the remaining orange ground 

 colour entirely \ mostly though reducing it to irregular, often confluent 

 patches, above and below the bases of subventral warts, thus appearing as 

 broken, irregular bands, even with the mature larvae. 



With their fifth moult the larvae reach a length of 3.0 to 3.5 Cm., 

 and feeding voraciously at this somewhat lengthened period, grow con- 

 siderably, reaching at maturity a length from 4.0 to 5.0 Cm. This rapid 

 growth naturally seems to cause a tension of the skin, and the dull, rather 

 greasy, dark coffee-brown colour, before more confined to the segmental 

 folds and subventral region, now prevails again and tl>e velvety-black 

 appears reduced to large quadrangular patches, from which warts I., II. 

 and III. arise. 



The dorsal stripe, rarely fully present with the mature larva, is 

 generally retained on three first (thoracic) and two last (8th and 9ih 

 abdominal) segments as a fine, obscured whitish line. Fifth to ninth 

 segments have each one irregular, white to brick-red spot, much obliterat- 

 ed, mostly on fourth and tenth segment. Individuals entirely free from 

 dorsal line or spots are darker coloured even subventrally. 



The warts of the mature larvje vary from bright black to gray and 

 glassy bluish-white ; while subventral warts are even sometimes orange. 

 The light coloured warts are covered with minute black dots, from which 

 the bristles are emitted. 



