2 DISTRIBUTION AND DISPERSION OF LEPTINOTAKSA. 



The genus Leptinotarsa is confined almost entirely to the continent of North 

 America, 1 extending southward to the Isthmus of Panama and northward to 

 the northern United States. Forty-three species are known, of which three 

 have crossed the Rio Grande into the United States, and an equal number 

 have been found as far south as the Isthmus of Darien. By far the greater 

 portion of the species is found in southern Mexico ; only a few are known 

 from Guatemala, and a few from the Mexican Plateau. Within the genus 

 the species are arranged in groups, in each of which some one type of 

 coloration prevails to the exclusion of all others. Between these groups of 

 species there are no intergrades ; these are to be sought for in the parent 

 genus Zygogramma, where they are often clearly discernible. Specific dif- 

 ferentiation is almost entirely based upon coloration, is by no means easy, 

 and is especially difficult in dead specimens. The life histories are almost 

 entirely undescribed, and the figures of the species that have been published 

 are misleading, as in Jacoby's work in the Biologica Centrali Americana. 

 Many of the species are exceedingly beautiful in life on account of their 

 delicacy of coloration, but at death this is lost. 



The following species are known: 



Leptinotarsa calceata Stal. Leptinotarsa juncta Guer. 



novemlineata Stal. lacerata Stal. 



dilecta Stal. heydeni Stal. 



flavitarsis Guer. puucticollis Jacoby. 



nitidicollis Stal. modesta Jacoby. 



obliterata Chev. chalcospila Stal. 



lineolata Stal. dahlbotui Stal. 



pudica Stal. hogei Jacoby. 



typographica Jacoby. haldemani Rogers, 



distinguenda Jacoby. libatrix Suffr. 



cacica Stal. violescens Stal. 



undecitnlineata Stal. chlorizaus Suffr. 



diversa n. sp. litigiosa Suffr. 



angustovittata Jacoby. tlascalana Stal. 



signaticollis Stal. rubiginosa Rogers, 



raultita^niata Stal. zetterstedti Stal. 



oblongata n. sp. stali Jacoby. 



rnelanothorax Stal. evanescens Stal. 



rubicunda n. sp. dohrni Jacoby. 



intermedia n. sp. belti Jacoby. 



defecta Stal. flavopustulata Stal. 

 decemlineata Say. 



1 A few species of Leptinotarsa are described from the northern and western portions 

 of South America. There seem to be southward extensions of the northern forms. Little 

 is known concerning them. The references to Leptinotarsas from South America are 

 usually incorrect, or misprints (as in several instances). In other cases there is uncer- 

 tainty as to the source of the described material. 



