OF WASHINGTON, VOLUME XI, 1909. 153 



disappear with death, as they are said to do in these species of 

 Leptinotarsa. Unfortunately Tower has not specified what 

 these colors are and how they are distributed. Should these 

 colors prove to be of the physiological character indicated, per- 

 sons studying these beetles at different seasons would naturally 

 conclude that the differences in coloration were of specific 

 value ; or even the same individual, in ignorance of their trm- 

 nature, would be led into error. 



Cases of nuptial colors occur in certain species of Halticini, 

 although they appear to be much less frequent in this group 

 than in the Cassidini or Chrysomelini. A conspicuous example 

 is Disonycha quinque-vittata Say, a common species upon wil- 

 lows in many parts of North America. These beetles, when 

 found in the late summer have pale yellow elytra with narrow 

 black longitudinal stripes. When the beetles emerge from hi- 

 bernation the following spring the elytra show in addition a 

 large amount of crimson, disposed in broad stripes in the 

 intervals between the black lines. A Mexican halticid, Homo- 

 phccta abdoniiiialis Chevrolat, which the writer found common 

 at Cordoba, develops nuptial colors. During the winter months 

 these beetles were frequently found upon their food-plant. 

 They then had dull bluish black elytra, while the pronotum 

 and most of the legs were a pale ivory-yellow. When the 

 season of sexual activity arrived, with the rains and the warm 

 weather, the pronotum and the legs changed to a delicate rose- 

 red, while the elytra showed a peculiar blue sparkle. 



No indications of nuptial colors have been found in the two 

 great groups of Camptosomata and Eupoda. While it is true 

 that our knowledge of the biology of these groups is very in- 

 complete, these groups, and particularly the one first mentioned, 

 stand apart in many ways and one can hardly expect close 

 correspondence in the more specialized traits. What does 

 cause surprise is that the Hispini, which are so intimately linked 

 with the Cassidini, show none of the remarkable color-changes 

 so frequent in the latter group. But this may be due wholly to 

 our incomplete knowledge, and perhaps, when the tropical 

 forms have been investigated, this phenomenon will be found 

 among the Hispini also. 



These notes demonstrate how meager is our knowledge of 

 the biology of this important group of beetles. Our literature 

 of economic entomology abounds with more or less extended 

 notices of the injurious species, yet it is rare to find an original 

 observation recorded. The accounts are mostly borrowed 

 from earlier authors, and such additions as are made, from 

 scattered records and without critical knowledge, are, more 

 often than not, inaccurate and misleading. 



