olo 



dry ends of the lower spurs of the niouutaiiis, in the sides 

 of the gulches, in the marshes, along the sea shore and in 

 some of the more arid regions where the lack of surface water 

 checked the wa)iderings of the cattle. 



The endemic insects, being as a rule hut little adaptable 

 to new host plants, receded with the plants to which thev 

 were attached. 



With the spread of cultivation and the introduction of 

 hundreds of species of plants for economic purposes or for 

 ornamental plantings for many years entirely without any 

 system of port examination and quarantine, many insects at- 

 tached to these plants were introduced and became established. 

 Some of these entered into direct competition with endemic 

 lowland insects. Other insects, however, which were para- 

 sitic and predaceous upon the introduced insects soon 

 adapted themselves to attack the endemic lowland insects and 

 reduced their numbers. .Vmong these one species is doul)t- 

 less more important than all the rest. The ant, Pheidole 

 megacephala. is eminently predaceous in its habits, attacking 

 other insects indiscriminately and wherever it has spread 

 the endemic insect fauna has practically disappeared, only a 

 few Hymenoptera, such as species of Crahro, Odyncrus and 

 Nesoprosopis, some Coccidae, Jassidae, and Delphacidae among 

 the Homoptera, some Ileteroptera, some Lepidoptera and pos- 

 sibly some Diptera have been able to survive where this ant 

 is able to nuiintain itself in its full numbers. But none (tf 

 the characteristic grou])s of endemic Coleoptera are able to 

 persist where it is found since they are generally sluggish, 

 of feeble powers of flight, and defenseless against the attacks 

 of the myriads of ants present in the cultivated area of the 

 islands. 



It has been generally recognized that the cooler and 

 generally damper climate of the mountains forms an im- 

 passable barrier to the spread of Pheidole, but it is not so 

 well known that there are certain of the dryer areas of the 

 lowliMids in wliich it is unable to maintain itself. Since these 



