THE SEMITROPICAL ARMY WORM. 55 



covered Avitli whitish down, from the body of the female. They are 

 distinctly green when first deposited and have the appearance illus- 

 trated at 1) and <■. 



The larra. — The caterpillar resembles that of the other two species 

 of Prodenia sufficiently to be naturally referred to that genus, and 

 it is subject to similar variation in color. The ground color is dark 

 grayish in pale individuals and nearly black in the dark forms. 

 These latter, especially when approaching maturity in the penulti- 

 mate stage, are sometimes so dark as to resemble Mamestra. The 

 body is ornamonte<l with a narrow, slightly interrupted, median yel- 

 low longitudinal dorsal strij^e, a similar slightly wider dorso-median 

 stripe, and a Avide and brighter j'-ellow substigmatal stripe, which 

 becomes obscured in the thoracic segments of the penultimate stage. 

 In the very dark forms the triangular velvety dorsal spots character- 

 istic of the genus can scarcely be seen, and in the paler forms they are 

 seldom as distinct as in the other two species. "N^Hien full-grown the 

 larva measures about an inch and a fourth to an inch and a half in 

 length (25-37™™), and the width varies from one-fourth of an inch 

 to a little larger. The head measures nearly 2.5""". 



The mature larva is illustrated at / and g of figure 8 and a dark 

 form nearly grown at e. 



The fiifd. — The pupa resembles closely that of Prodenia comme- 

 Unn\ The head and abdomen are well rounded. The color is 

 mahogany-brown, with the head, spiracles, and anterior edges of the 

 alxlominal segments darker. The surface is smooth and shining, 

 with the anterior edges of the abdominal segments fineh^ punctured. 

 The anal segment terminates in a two-spined cremaster-like process. 

 Length, IG-IS™™; width, 5-G™™; length of head to end of the wing- 

 cases, 10™"\ 



The following technical description of the egg and larval stages 

 was kindly contributed by Dr. II. G. Dyar. 



TECHNICAL DESCRIPTION OF I'lIE EOG AND LARVAL STAGES. 



TJie PfKi. — Ileniisplierical. smooth, pale si'een. shinins; ribs very fine, 

 obscure, nuinerous, ill-defined, radiating from the micro])yle; cross-strijie imper- 

 ceptible. l>iani('ter, (>.(■>'»"'. Laid in a patch, covered by a thin layer of whitish 

 wool. 



Stfif/c I. — He.ad rounded, bilobed. mouth pointed, shining greenish-black; 

 eyes black, mouth brown; width about o.;}""". Body robust, uniform, joint 12 

 slightly enlarged, feet of joints 7 and S a little smaller than the others and not 

 used in walking: translucent greenish, cervical shield, leg plate.s, thoracic feet, 

 anal plate, and the large round tubercles shining black; tubercles i and ii of 

 joint 12 in a squai'e; seta^ rather coarse, moderate, black. simi)le. 



Stage II. — Head rounded, slightly bilobed. the vertex level with joint 2, shin- 

 ing Inteous, blackish .^shaded over the vertices of the lobes; ocelli black, mouth 

 brown, width, 0.4"'"'. Body somewhat thickened at joints ."> and 12, feet normal, 

 equal ; greenish luteous, cervical shield and anal plate blackish infuscated ; 

 55968°— Bull. 66—10 5 



