Materials, Their Taxonomy and Natural History 61 



Pattern elements all present but variable. Pronotnni rather coarsely punctate, 

 often strongly so on lateral and posterior portions, center more freely punctate, 

 polished. Pattern: All elements present but highly variable, from mere trace 

 to extensive fusions, a' and a always divergent, forming V more or less open. 

 Scutellum yellow-brown, smooth, polished, edges darkened. Elytra, in sexu- 

 ally mature specimens, pale yellow or straw-color, often more yellow or even 

 yellow-red, variable with locality, food and age; anal border black, 5 longi- 

 tudinal stripes, edges with irregular double row of moderate punctations, 

 second stripe often united to third and these in turn to fourth stripe posteriorly ; 

 interspaces not raised, polished, costal edge inflexed, fiat, or slightly concave, 

 smooth, polished, yellow or brownish ; hind wings strong, well developed, trans- 

 parent, reddish or bright red in center, darker yellow or brown on costa and at 

 base, variable. Below : Yellow-brown with pattern elements all present, variable, 

 often much fusion; thoracic and abdominal surfaces smooth, polished, rarely, 

 faintly punctate ; legs, femora and tibia yellow brown or reddish, rarely black, 

 joints darker brown or black, femora smooth, polished, rarely and freely 

 punctate ; tibia, few irregular, variable, well-marked punctures and spines. 



Size : Female variable ; male, 7 to 16.5 mm. long, 4.5 to 9 mm. broad ; female, 

 8 to 12.5 mm. long, 5.5 to 10.25 mm. broad. 



Sexes: Female with sternal sclerite of last abdominal segment rounded com- 

 plete ; male with same sclerite truncate, faintly notched, rarely grooved. Female 

 larger than male, more rounded and broader behind; male more elongate in 

 form and often very small. 



Food: S. tuberosum^ S. rostratum, and more rarely many species of Solanum. 



JxrvENiLE Stages. 



(Tower, 1906, plate 17, figs. 19, 20, 21.) 



Eggs: Laid in bunches, 5 to 200, not often stalked, oval, polished, smooth, 

 concave on ventral side; length 1.T5 to 2.50 mm., breadth 0.75 to 1.1 mm. 

 Incubation, 5 to 15 days ; average 6 or 7 days. 



First larval stage : Head, pronotum, and legs, black ; body red with full set of 

 color markings, often spined. Length at end of stage, 3 to 4.5 mm. 



Second larval stage: Head and legs, black; pronotum, posterior edge black, 

 anterior portion red, reddish yellow, or brown ; body red, varying in tint with 

 the condition of the animal, food, climatic conditions, etc., baso-pleural and 

 few anterior inner tergals present. Length at end of stage, 5 to 6.75 mm. 



Third larval stage: Like second stage, color variable; length at end of stage, 

 11 to 17 mm. (Plate 12, fig. 2.) 



Length of larval life, from 10 to 28 days ; average between 13 and 15 days, 

 but much depends upon food and climatic conditions. 



Pupa : Pupates in ground, from 1 to 5 inches below surface ; pupa reddish 

 yelloAv. Pupation lasts from 6 to 15 days, but averages 8 to 10 days. 



Length of ontogeny: 21 to 58 days; averages between 28 and 31 days. 



Geographical Distribution. 



(Plate 5.) 



North America, eastward from the foot of the Rocky Mountains to the 

 Atlantic coast, northward into Canada, and northeast throughout the St. Law- 

 rence Valley, southward to the Gulf coast and to lower Texas. Common in most 

 localities; is everywhere a grassland form and becomes a serious agricultural 

 pest in many areas, especially in the north and east. (See Tower, 1906, for 

 further account of distribution and migration.) 



