1912] Mann — A Protective Adaptation in a Brazilian Membracid 145 



THE STANFORD EXPEDITION TO BRAZIL, 1911. 



J. C. BraNNER, Director. 



A PROTECTIVE ADAPTATION IN A BRAZILIAN 

 MEMBRACID. 



By Wm. M. Mann, 

 Bussey Institution, Harvard University. 



On his first visit to the tropics a collector is sure to have a great 

 many disappointments, especially if he has preconceived ideas as to 

 what he expects to find there. My first surprise came at Para, 

 almost as soon as we landed, when in company with Dr. Heath, I 

 spent the evening collecting at arc lights. Our pockets were full of 

 collecting jars, but we returned, having seen one cockroach and 

 nothing more. Of course, later on we had fair collecting at lights, 

 but in general, conditions were qviite unlike our imaginations had 

 pictured them to be. There were noticeable exceptions to the 

 rule, in particular two insect groups ants and the Hemipterous 

 family Membracidse, which not only came up to our expectations but 

 surpassed them, the former on account of their great abundance 

 and tlie latter because of the varied and bizarre structures which 

 were quite in accord with our ideas as to what tropical insect life 

 should be. 



In the Membracidse there seems to be no limit in structure 

 beyond which the pronotum will not develop. It may resemble 

 in miniature a Roman helmet, an anchor or a pawnbroker's sign, 

 often being so large and awkward looking that one would think it 

 an actual hindrance to the insect. This awkward appearance 

 impresses one most when the insects are removed from their natu- 

 ral surroundings. On their food plant they are not more notice- 

 able than insects of simpler structure, while some are even good 

 mimics of galls, seeds, fruit and other objects of a vegetable nature. 

 Poulton^ in an interesting and detailed paper has pointed out the 

 resemblances of many of the Membracidse to various plant growths 



1 Suggestions as to the Meaning of the Shapes and Colors of the Membracidae in the Struggle 

 for Existence, in Buckton's Monograph of the Membracidae. London, 1903. 



