DIABROTICA. 533 



a. Elytra dark-coloured, with longitudinal testaceous vittw ; the interspaces 



generally costate. 



69. Diabrotica corusca. 



Diabrotica corusca, Harold, Coleopt. Hefte, xiii. p. 92 (1875) x ; Baly, Journ. Linn. Soc, Zool. 



xix. p. 230 2 . 

 Diabrotica alternans, Sturm, in litt. 



Hob. Mexico, Presidio (Forrer), Teapa, La Parada, Oaxaca 2 (Salle), Jalapa, Cordova, 

 Chilpancingo, Colima city, Acapulco (Soge) ; Beitish Hondueas, R. Hondo (Plan- 

 caneaux) ; Guatemala (Salle), El Reposo, Las Mercedes, Cerro Zunil, Rio Maria Linda, 

 Capetillo, San Geronimo, Teleman, Chacoj (Champion) ; Hondueas (Salle) ; Nicaeagua, 

 Chontales (Janson, Belt) ; Costa Rica (Van Patten), Cache (Rogers) ; Panama, Bugaba, 

 Volcan de Chiriqui (Champion). — Colombia 1 2 . 



The typical form of D. corusca may be known by the two metallic blue stripes 

 (sutural and sublateral) of the elytra, these stripes being separated by a subsutural 

 flavous longitudinal band occupying two costEe which are wider than those placed on 

 the rest of the surface. In respect of colour and size the insect varies greatly, many 

 specimens obtained in Chiriqui having the elytral stripes of a pale fuscous colour, and 

 the head varying from black to fuscous or obscure fulvous ; intermediate degrees in 

 shade of colour are also before me, but structural differences of importance I cannot 

 detect. According to Mr. Champion this and several closely allied species principally 

 affect Cucurbitaceous plants, both wild and cultivated. 



70. Diabrotica fairmairei. 



Diabrotica fairmairei, Baly, Trans. Ent. Soc. Lond. 1886, p. 447 \ 



Hdb. Mexico \ Juquila, Cordova, Orizaba (Salle), Mexico city, Jalapa, Cordova, Chil- 

 pancingo (Soge) ; Beitish Hondueas, R. Sarstoon (Plancaneaux) ; Guatemala (Salle), 

 near the city (Salvin), Cerro Zunil, Panajachel, Zapote, Capetillo, Duenas, San Geronimo, 

 Purula, Sabo, San Juan in Vera Paz, Cahabon (Champion) ; Nicaragua, Chontales 

 (Belt) ; Costa Rica ( Van Patten), Irazu, Cache (Rogers). 



D. fairmairei has been separated by Mr. Baly from D. corusca and D. innuba on 

 account of the third elytral costa being the widest, while in the two last-named species 

 the second and third costse are wide and equal ; I may add to this that in D. fairmairei 

 it is the third costa which is flavous in colour, the others, with the exception of the 

 lateral margin, being either fuscous, violaceous, or bluish. I do not think that much 

 reliance can be placed on the colour of the head ; it is, however, usually dark or 

 Teddish-fulvous with a more or less violaceous hue, but in many specimens much 

 darker and nearly black. D. fairmairei does not seem to extend further south 

 than Costa Rica, but is replaced by several closely allied forms in the State of 



