OF WASHINGTON, VOLUME XI, 1909 83 



SOME SPECIES OF CALLIGRAPHA. 



[Coleoptera, Chyiomelidae.] 

 BY FREDERICK KNAB. 



In those forms of Calligrapha in which the pale elytra 

 show a pattern composed of sntural stripes, humeral lunules, 

 and a number of irregular spots, the specific limits have been 

 largely a matter of individual opinion. This must continue to 

 be the case while collectors and systematists are content to 

 dispose of such questions by a furtive examination of the speci- 

 mens that chance puts in their way. The writer has long been 

 dissatisfied with the accepted definition of the species and for 

 some years has observed these beetles in nature whenever 

 opportunity offered. It has become constantly clearer that 

 distinct species are confused under the same specific name and 

 that the definition of the species will have to be entirely refor- 

 mulated. While the writer is not prepared to do this at present 

 it seems advisable to characterize a few of these forms and it 

 is hoped that this will stimulate others to give their attention to 

 this group. Determination of the food-plants of the different 

 species is the key to a proper understanding of them ; unfortu- 

 nately our knowledge in this direction is still very incomplete. 

 Furthermore, it is only with large series before him that the 

 student can hope to gain a mastery of these difficult forms. 



The two species described here as rhoda and rowcna group 

 with scalaris LeConte. There seems to be no doubt as to the 

 form LeConte had before him when he described scalaris. It is 

 the one which occurs upon the elm (Uliiins aincricana L.) and 

 the linden (Tilia americana L.) and the form most frequently 

 referred to under the name scalaris. In Calligrapha scalaris 

 the pronotum and the elytral pattern are bright metallic green, 

 sometimes with a strong bluish cast ; the form is rather elong- 

 ate and depressed and the size averages larger than any of the 

 other species. The surface appears shining; the punctuation 

 of the pronotum is moderately coarse and close at the sides, 

 fine and sparse upon the disc, though subject to considerable 

 variation. The punctures limiting the elytral pattern are rather 

 fine, the markings are flat, and show little if any convexity. 

 The punctures upon the disc are very fine and well separated. 

 The white ground-color of the elytra shows a silvery luster 

 in sexually mature specimens. 



Calligrapha rhoda, new species. 



Form subovate, convex. Color of the body and elytral pattern dark 

 olivaceous, submetallic; the legs, antennae, and palpi ferruginous yellow. 



