LEPTINOTARSA. 235 



21. Leptinotarsa dahlbomi. (Tab. xiii. fig. 23.) 



Myocoryna dahlbomi, Stal, Diagn. 1859, p. 317; Monogr. Chrys. Amer. p. 166 *. 



Hab. Noeth Ameeica, Texas 1 . — Mexico \ Yolos, Puebla (Salle), Yucatan 1 (Pilate, 

 coll. SallS) ; Nicaeagua, Granada (Salle). 



This species does not seem to be common in Mexico, to which country it is 

 principally restricted. It has not been met with by Mr. Champion in Guatemala; 

 nor by Janson or Belt in Nicaragua, whence a single specimen is contained in .the 

 collection of M. Salle. I may add to the description given by Stal, that the sides 

 of the thorax are crowded with strong punctures, and that the yellow elytral stripe 

 is distinctly narrowed at the shoulder, where it is of only half the width of the rest. 

 The commencement of the sutural stripe, however, is widened immediately below the 

 base in all the specimens before me. 



22. Leptinotarsa haldemani. 



Doryphora haldemani, Rogers, Proc. Ac. Phil. 1856, viii. p. 30 1 ; Suffr. Stett. ent. Zeit. 1858, 

 p. 248 2 . 



Hab. Noeth Ameeica 12 . — Mexico 2 , Ventanas (Forrer), Puebla, Cuernavaca (Salle), 

 Almolonga (Edge). 



According to Silurian the present species is one of four which, although distinguished 

 by very obscure differences, yet he believes to be distinct. Amongst more than a 

 hundred specimens which are before me, on account of the great variability of the 

 insects I am unable to agree with Suffrian, and can only distinguish, at the most, two 

 species, though, if I were to take these slight differences into account, I might easily 

 multiply the species to six or eight. Since most of the specimens which T have for 

 examination were obtained in different yet in limited localities, and still show variation, 

 I must conclude that the species is a very variable one. 



L. haldemani is perhaps the only one which is easier to recognize than the rest on 

 account of its black head and thorax (the only species in which these parts are of this 

 colour) ; but shape and punctuation are as variable as in the others, and so many inter- 

 mediate forms are before me that I cannot be certain to which species in Suffrian's 

 sense I am to refer them. A specimen of the present insect, contained in Mr. Baly's 

 collection, and named by Dr. Horn, agrees also with the description given by Suffrian ; 

 others from different parts of Mexico agree with this specimen in the black and opaque 

 colour of the head and thorax, and also in the shape of the latter, which is more 

 straight and concave at each side near the base than in the other species; but the 

 punctuation shows all degrees from minute and distant to close and more strongly 

 impressed punctures. There may in reality exist but one species, which point, I think, 

 can only be settled by resident entomologists. 



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