36 Introduction 



Mr. Harold Morrison identified the coccids; the Hymenopterous 

 and Dipterous parasites of the latter were studied by Prof. C. T. 

 Brues and Dr. E. P. Felt. Dr. J. Bequaert, Prof. Herbert Osborn, 

 Prof. J. W. Folsom and Dr. R. V. Chamberlin identified a wasp, 

 two Membracids, a Collembolan and a Myriopod found living in 

 Tachigalia petioles; and Prof. Roland Thaxter found and iden- 

 tified a fungus growing on the surfaces of one of the species of 

 social beetles. I have added the reports of several of these inves- 

 tigators as appendices to the present paper, and wish to express 

 my great indebtedness to all of them for their generous assist- 

 ance and to Mr. Wm. Beebe for his many kindnesses to Prof. 

 Bailey and myself while we were at Kartabo and the pains he 

 has taken, since our return to Boston, to ascertain further facts 

 concerning the Tachigalia and other myrmecophytes and to 

 collect additional species of Formicidse. So many of the ants in- 

 habiting the Tachigalia prove to be new to science that I have had 

 to provide a special paper for their taxonomic descriptions 

 (Zoologica III, No. 4). 



Although I have endeavored to acquire a comprehensive 

 knowledge of the various insects associated with the Tachigalia, 

 I am aware that my account must be very fragmentary. The 

 territory covered was limited and in other parts of British Guiana 

 the same tree undoubtedly harbors other insects. This is indi- 

 cated by the few published observations on the trees of the genus 

 Tachigalia and their insects in Brazil and other parts of South 

 America. Moreover, only the leaves and petioles and their 

 inhabitants were studied and there are probably many peculiar 

 insects that live only in the wood and seeds or merely visit the 

 flowers, which in some species, at least, are conspicuous and 

 sweet-scented. The seeds were found only after they had germi- 

 nated, and the trees showed no indications of flowering during 

 our stay in British Guiana. Our inference that they might bloom 

 during the winter months has not been confirmed, since up to the 

 time of this writing (March, 1921), Mr. Beebe has seen no 

 flowers on any of the trees which Prof. Bailey marked for obser- 

 vation. I trust, nevertheless, that my account of the Tachigalia- 

 biocoenose will give such a picture of the astonishing complexity 

 and exuberance of the insect fauna of the Neotropical Region, 

 and of the fierce competition among these organisms on the one 



