52 The Philippine Journal of Science isn 



lacking at Los Banos, yet the same spirit of hospitality and 

 the desire to assist visiting naturalists are present, and it is 

 to be hoped that at a not too far distant date means will be 

 found to enable workers to take full advantage of this wonderful 

 botanical and entomological field. 



As an economic entomologist who has spent a number of years 

 traveling in the Malay and South Pacific Islands in search of 

 beneficial insects, I can fully appreciate the practical value of an 

 entomological station in such a locality. Why should the moth 

 sugar-cane borer {Diatrsea striatalis Sn.) be so numerous and 

 destructive in Java and Formosa and rare in the Philippine 

 Islands? Why should one species of leaf -hopper (Perkinsiella) 

 nearly ruin the sugar industry in the Hawiian Islands 

 and seven species do only minor damage in the Philippine 

 Islands? What keeps in check the thousands of phytophagous 

 insects of great fecundity and rapid development that inhabit 

 these tropical islands? These and similar problems when 

 solved ynW be the saving of valuable crops all over the Tropics, 

 and the knowledge of these subjects will enable us to reason on 

 biological subjects, such as natural selection and evolution, with 

 a better understanding. In the past experimental zoology has 

 been undertaken almost entirely in temperate climates, but in 

 the future a great portion of this will be done in the Tropics 

 on account of the greater facilities. Biologists working on the 

 laws of inheritance often have to wait a year for one generation 

 in the Temperate Zones; whereas, in the Tropics, it would be 

 possible to have ten or a dozen in the same period. For these 

 and for other reasons I would plead for biological stations in 

 such localities as Mount Maquiling — even if, by so doing, I stray 

 away from the subject of this paper. 



In a former paper " I attempted to tabulate all of the genera 

 of Derbidae. Since then many forms have passed through my 

 hands, and the tables have stood the test fairly well. Except 

 in certain details I am not inclined to make many alterations 

 in that work. What I formerly called groups I now treat as 

 subfamilies. Nisia and its allies I excluded from the family; 

 Derbe and Mysidia I at present place with the Zoraida group; 

 Rhotana, along with five or six allied genera, remain in old group 

 IV (Rhotaninae). 



The horismology of the neuration is indicated in the figures; 

 the "shoulder keels" are well-developed carinae extending from 

 the anterior margin of the pronotum near back of eye to the 



'Bull. Hawaiian Sugar Planters' Assoc, Div. Ent. (1913), 12. 



