MEMOIES OF THE NATIONAL ACADEMY OF SCIENCES. 107 



UaiTis. Ins. Inj. Veg.. Flint's cilit., \>. 429, 1862. 



^;)«(e:iiul Hohiiisoii (iiuoti" Angus in lit.), Proo. Eiit. 8oc. I'hilad.. vi, ji. 11, 1866. 



/)'. D. Il'al«h, I'r.actical Eutoni., ii, p. 7, LSIifi. 



Man-is, Kutmu. Corre-sp., p. 308, pi. 2, fig. 4, 186il. 



Le Baron, 4tli Illinois Rept., p. 186, 1873. Lite history (figs.). 



French, Trans. Di-pt. Agr. 111., xv, p. 189, 1877. 



J. Marten. Trans. Dept. Agr. 111., xviii. Ajipend.. p. 111). 18"i0. 



I). Coijiiillcit, Trans. Dept. Agr. Ill,, xviii. Append., p. 167. 1880. 



/)'. Saunders, Ins. Inj. Frnits, p. 61, 1883. 



fr. BcntenmiiUer. Can. Ent., xx, p. 16, 1888. (Egg and all tlie larval stages.) 



Lurjijer, Bull. 10, Agr. Stat. Univ. Minnesota, p. 78, JIarch. 1890, PI. I. fig. 5, larva; PI. II, fig. .'i, uiotb. 



jlfoth. — Fore wiutfs and base of thorax above ciunanion (Ridg.,' Ill, 20); costal sbade russet 

 (Ridg., Ill, 10). not well marked. Thoracic patch ochraceous (Ridg., V, 7) in front, shading 

 po.steriorly into chestnut (Ridg., IV, 9). Lines and discal dots as in J), uiujtt.sii, hut the di.scal 

 dots are freciuently ob.solete, and the outer one, when well marked, is seldom linear. The sparse 

 irroration, lines, discal dots, and fringe all concolorous, mars brow-n (Ridg., Ill, 1.3). Outer margin 

 of lore wings distinctly scalloped, and hind wings also percejjtibly so. Hind wings ])a]e straw- 

 yellow, cream buff (Ridg., V, 11), immaculate or slightly shaded with brown; abdomen a little 

 darker. Underside a little darker than hind wings above, shading into brown on fore wings, 

 especially toward the outer margin. Fringe dark, as above. 



E.\pan.se of wings, 42-53 mm. 



Paler in color than J>. anf/Ksii; darker than J>. califoriiica; distinguished from T>. drexcln 

 and i). major by its smaller size and less distinct discal dots; from 1>. dredeUi further by the 

 absence of a strongly contrasting costal shade; from D. major by the usually paler secondaries; 

 but in this last instance specimens may occur very difficult to distinguish (Dyar). 



The following description of preparatory stages of Datana 7)iinistnt is by Mr. Bcutenmiillcr 

 (Can. Ent., xx, p. 16): 



Egg. — Pure white, ovoid, with fiatteued base, the apex with black dot showing impregnation. Laid in masses, 

 from 25 to 50 on underside of leaf. 



Young larra. — Head black, .shining, second segment orange-brown in front, cervical shield black. Body-color 

 chestnut-brown, with the stripes a little darker, anal clasps anil thoracic feet jet black. Length, 3 mm. 



Jfter first moU. — The bead jet black, as is also the whole of the secon/rt segment and anal segment. Body-color 

 now much darker, as are also the stripes, these being almost obscured, except along the lateral region. Thoracic 

 feet black. Length, 12 mm. 



After second molt. — Head black, rather small; second segment yellow except the cervical shield, black. The 

 thoracic feet, abdominal and anal legs, and termination of anal segment jet black, while the stripes are very clear 

 yellow on the chestnut-brown ground. Scattereil over the body are also a few short sordid white hairs. Length, 

 20 mm. 



Until after this molt the larva- feed upon the underside of leaf (parenchyma), and do not attack the ed"-es 

 until after the third molt begins. 



After tliird mutt. — Head jet black, second segment orange, cervical .shield black. Body color reddish brown 

 with rather broad yellow stripes; anal clasps, tip of legs, and thoracic feet jet black ; underside striped equally with 

 reddish brown and bright yellow. Length, 30 mm. 



After fourth molt. — Head jet black, neck yellow, cervical shield jet black, shining. Body chestnut-brown, the 

 stripes bright yellow and equidistant ; the feet and anal clasps jet black, abdominal Ipgs yellow-banded, with jet 

 black outside. The hairs over the body are now quite long. Length, 33 mm. 



Stage next to last. — Length, 26 nnu. Head black, as wide as the body. First thoracic segment black. The 

 body is yellow, not greenish yellow, as in the adult, and the stripes are reddish brown, the color of brown roofing 

 slate. .Inst before molting the first thoracic segment becomes gamboge-yellow on the plate and straw-yellow around 

 the edges. A broad dorsal reddish-brown line, fully twice as wide as the others. There are four lateral stripes, all 

 of the same width, the yellow sjiaces between them only a little more than one-half as wide as the brown bands. 

 The third brown band includes the black spiracles. Thoracic feet black; suranal plate and anal legs black; midiUo 

 abdominal legs dark, four of the legs pale livid reddish; planta' pale. The hairs are minute, short, not apparent 

 without a lens. 



The head and thoracic segments often held bent over backward, so that the thoracic feet stick u)i, while the 

 tail is so bent up as to nearly meet the bead. 



Last stage. — Length, 30 mm. Head Idack. Body with white, conspicuous hairs, many of them one-third longer 

 ithan the body is thick. The body is now distinctly greenish yellow, and the prothoracic plate gamboge-yellow. 



'See Ridgwav's Nomenclature of Colors. 



