DIABEOTICA. 515 



29. Diabrotica chontalensis. 



Fulvous, the head and breast black ; the second and third joints of the antennae very short, equal ; thorax sub- 

 quadrate, impunctate, without fovese ; elytra finely punctured, a ring-shaped mark at the base, and a semi- 

 lunate one below the middle, metallic blue. 



Length 3 lines. 



Eab. Nicakagua, Chontales (Janson). 



I am obliged to separate this insect, of which only a single example was obtained, 

 from the many closely-allied forms with similar elytral pattern ; from all of which it 

 differs in the very short second and third joints of the antennae, these joints being of 

 exactly the same length, the reverse being the case in the allied species. The 

 antennas are entirely dark fulvous (the basal joints somewhat lighter) and are nearly as 

 long as the body. The elytral markings are similar to those of D. circulata, but the 

 thorax has no foveas and is nearly quadrate in shape ; the punctuation of the elytra is 

 arranged in closely approached irregular lines. 



e. Elytra partly (the thorax entirely) green. 



30. Diabrotica viridicollis. (Tab. xxix. fig. 2, var. ; Tab. xxx. fig. 9.) 



Pale greenish, the head, the antennae partly, and the tibiae and tarsi obscure fulvous : thorax green, scarcely 

 foveolate ; elytra fulvous, the sides dark green, the suture and a lateral stripe anteriorly, and a transverse 

 band near and another below the middle, piceous. 



Length 3-4 lines. 



Head dark fulvous or obscure pieeous, foveolate between the eyes ; antennas two thirds the length of the body, 

 of variable colour, the second joint very short, the third one half longer, the basal joint generally pale green, 

 the following joints obscure fulvous or fuscous, the two or three apical ones flavous ; thorax subquadrate, 

 dark green, shining, without impressions or with a minute fovea on each side, the surface impunctate ; 

 scutellum black ; elytra closely punctured, with a longitudinal depression below the shoulder, pale fulvous, 

 the sides with a narrow longitudinal green band extending to the apical margins, this colour being bounded 

 anteriorly by a piceous stripe extending to the anterior transverse band which it joins, the basal and 

 sutural margins also piceous in colour, a similarly-coloured band below the middle, extending as far as 

 the lateral green band ; femora and the abdomen green, the breast obscure piceous. 



Hal. Mexico, Oaxaca (Salle), Tapachula in Chiapas (Edge) ; Nicaeagua, Chontales 

 (Janson, Belt); Panama, Bugaba (Champion). 



In some examples the elytra are more shining, and have the markings similar to 

 those of D. biannularis and D. adelpha, and the abdomen flavous instead of green ; I 

 believe these specimens, however, to be only a variety, as all other characters are 

 present. D. viridicollis may be known from its allies by the colour of the thorax and 

 elytra. From B. sex-maculata it differs in the colour of the antennae ; and in the shape 

 of the flavous spots of the elytra, these spots being rounder and divided by black bands, 

 and the lateral margins only of a green colour ; the terminal spots occupy the entire 

 apices of the elytra. We figure two examples : one from Chontales (Tab. XXX. fig. 9) 

 and another, a variety, from Bugaba (Tab. XXIX. fig, 2). 



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