DIABEOTICA. 



539 



b. Elytra light-coloured, with longitudinal Hack or blue stripes. 



83. Diabrotica cava. (Tab. XXXI. fig. 7.) 



Galleruca cava, Say, Bost. Journ. Nat. Hist. i. 1835, p. 198 1 ; Complete Writings, ii. p. 668. 

 Var. Head partially or entirely black ; thorax with or without two small black spots. 



Hob. Mexico \ Monclova and Saltillo in Coahuila (Dr. Palmer), Yolos, Etla, Tuxtla, 

 Cordova, Toxpam, Oaxaca, Guanajuato (SalU), Durango city, San Juan del Rio, Villa 

 Lerdo, Cordova, Jalapa (Edge); Guatemala, Quezaltenango, Duenas, Capetillo, San 

 Geronimo (Champion) ; Costa Rica, Volcan de Irazu (Bogers). 



Say's description 1 of D. cava is sufficient for the recognition of the species ; the 

 author, however, makes no mention of a shorter or longer black stripe on the upper 

 edge of the femora and on the outer side of the tibiae and tarsi, a character constant 

 in all the specimens before me. The head and thorax are of a reddish-fulvous colour 

 in the typical form ; the thorax is closely punctured and has two deep fovese, one on 

 each side ; the elytra are strongly and closely punctured, with a sutural and a lateral 

 blue stripe, the latter not extending to the apex. The specimens from Saltillo and 

 Guatemala have an entirely or partly black head and two thoracic spots, and seem, at 

 first sight, to represent another species ; I am unable, however, to look upon them as 

 such, as so many intermediate degrees of colour and marking are before me. Examples 

 were also obtained having the vertex only black, the lower part of the face being 

 testaceous ; some of these forms have the thoracic spots, in others they are absent. 

 The punctuation of the thorax, as well as the depth of the foveae, is equally variable. 

 An example from Cordova is figured. 



84. Diabrotica vicina. 



Black, the lower part of the face flavous ; thorax closely and distinctly punctured, bifoveolate, with two small 

 black spots (sometimes absent) ; elytra closely and distinctly punctured, flavous, a narrow sutural and a 

 broader lateral stripe, black ; legs flavous, striped with black, the posterior pair black. 



Length 2-3 lines. 



Hab. Mexico, Saltillo in Coahuila (Br. Palmer), Ventanas (Forrer), La Parada, 



Guanajuato (Salle), Salazar (Edge). 



B. vicina differs from B. cava in the elytra being much more finely punctured, and 

 with black (instead of blue) bands ; in the typical form of B. cava the thorax is much 

 more coarsely punctured. In spite of these differences, which I look upon at present 

 as specific, I have grave doubts about their value as such. The characters, however, I 

 have pointed out as distinguishing B. vicina from B. cava are constant in six specimens 

 before me. 



85. Diabrotica decorata. (Tab. xxxi. fig. 6.) 



Oblong, dilated posteriorly, black, above testaceous, the vertex with two, the thorax with four, black spots ; 



3z2 



