OF WASHINGTON, VOLUME XV, 1913. OO 



species will have been omitted which should have been mentioned. 

 It has not been possible to so thoroughly review the literature as to 

 be reasonably sure even, of including all of the prominently injuri- 

 ous species, and it has often been impossible to decide upon the 

 proper economic status of a species from the authors' remarks. 

 These details, however, lose some of their importance when we 

 remember that the behavior of a given species in its natural habitat 

 does not necessarily warrant the conclusion that it would be equally 

 or more injurious if introduced into another country, though the 

 assumption that it would, under a new environment, maintain, 

 or even surpass, its reputation as a pest, is unquestionably a safe 

 one. Of special importance, however, is a knowledge of the food 

 habits and life history of a species, which considered in connection 

 with its original habitat and systematic position, furnish adequate 

 grounds for conclusions as to its probable dangerous or innocuous 

 character. 



Time does not permit to dwell on the many interesting questions 

 related to a subject of this kind, which, of itself, is too large to 

 properly be considered in an address of this character. For 

 instance, it would be of much biological interest, and of very prob- 

 able practical value to summarize our knowledge as to what 

 extent insects from other Zoological regions, as the Oriental, 

 Neotropical, Ethiopian, etc. have adapated themselves in the 

 Nearctic and in what life zones in North America they thrive and 

 prove noxious. As is well known, Palearctic forms, especially 

 European, constitute the bulk of our imported injurious pests, 

 though many exceptions must be noted. 



ISOPTERA. 



Practically none of the Neuropteroid orders of insects are injuri- 

 ous to crops, with the exception of the Isoptera, which contains 

 two families, many species of which are at times plant enemies, 

 but especially of houses and other wooden structures. 



The well known Termes lucifugus of Europe is a pest of buildings 

 also attacking garden crops. 



Termes obesus Ramb. is probably the species responsible for 

 the large amount of damage in India to houses, crops and trees. 

 In Ceylon Calotermes militaris Desn. and C. greeni Desn. are period- 

 ically pests of the tea plant. Termes lacteus Frogg. is destructive 

 to buildings about Sydney, and in the woods, builds tall rounded 

 nests or mounds, some of them 6 feet high. Coptotermes gestroi 

 Wasm. is destructive to numerous plants in tropical Asia, as 

 Hevea brasiliensis, mango, coco nut palm, etc. 



In- Formosa, Termes vulgaris Hav. is very destructive to sugar 

 cane, the insects eating the roots and parts below the soil, often 



