132 Psyche [August 



ON SOME TROPHOBIOTIC COCCID^ FROM BRITISH 



GUIANA/ ' 



By Harold Morrison. 



Bureau of Entomology, Washington, D. C. 



Representatives of all of the species of Coccidse discussed in 

 the following pages were collected by Dr. W. M. Wheeler of 

 Bussey Institution, Harvard University, in the course of his 

 investigatoins at the Tropical Research Station of the New York 

 Zoological Society in British Guiana and were recently submitted 

 to the writer for determination. Critical study of the material 

 available for examination in the National Collection of Coccidse 

 has shown that two of these species have also been collected in 

 certain of the West Indian islands by the writer and others, and 

 this opportunity has been taken to add these records to those 

 from British Guiana. 



SUBFAMILY MARGARODINvE 



GENUS STIGMACOCCUS HEMPEL. 



Stigmacoccus asper (Hempel) 



A number of specimens of this species were received with 

 the following note by Dr. Wheeler: 



"No. 757. Kartabo, B. G. Sept 5, 1920. Taken from a 

 huge colony of Crematogasfer sp. (near acuta Fabr.) nesting under 

 bark of a large standing tree. The nest covered an area df more 

 than 12 square feet and contained several hundred coccids 

 enveloped in black carton. The young coccids were golden 

 yellow, the older darker." 



'Published with the permission of r.he Secretary, U. S. Department of Agriculture. 



^ — The intimate relations described — as existing between ants on the one hand and the 

 various Homoptera — on the other hand — have a common peculiarity. In all of these cases 

 the ants are supplied with food in the form of an excretion or secretion elaborated from the 

 juices of the plants. Wasmann has therefore designated these relationships as trophobiosis to 

 distinguish them from the cases of myrmecophily proper — ." {.Wheeler, Ants, etc. New York, 

 Columbia Univ. Press, 1013, p. 360). 



