368 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1925 



We are sadly lacking, however, in our knowledge of larval forms 

 and in our ability at once to identify larvte without first rearing 

 the adults. In practical work, and especially in international or 

 intersectional quarantine, the most comprehensive knowledge of 

 larval forms is necessary, since in the operation of commerce in- 

 sects are carried accidentally quite as often in the larval form as in 

 the adult form. 



Work upon larval stages is going on at the present time with 

 some groups of lepidoptera, certain diptera, and the coleoptera. 

 Perhaps the most ambitious effort of this kind is that with the 

 last-named order. It is a great pleasure to know that Boving and 

 Craighead have almost finished characterizations, keys, and short 

 diagnoses of the families and subfamilies of the entire order 

 coleoptera. 



And, speaking of quarantine work, we should not only be able 

 to identify material found in whatever stage, but there is a great 

 deal that should be known which does not come properly under 

 this portion of this paper. It is becoming plain that (quarantines 

 may be promulgated which are unnecessar}'. We have been obliged 

 to go on the presumption that a pest in a given counti-y may be 

 and probably will be a pest in another country ; but such a decision 

 can not be made with full justice without a knowledge of the 

 ecology of the species in its original home. It would virtually be 

 imjjossible for any nation to carry out investigations of this kind 

 within the territory of another nation for any number of species 

 without international agreements and without the expenditure of 

 large funds, but, if we had known, for example, in this country, 

 in advance of the advent of the European corn borer, the ecological 

 facts concerning this species in Europe, which Mr. K. M. Babcock 

 is at present studying over there, we would have been in position 

 to attack tlie problem, perhaps not much more confidently, but 

 with a more exact idea concerning the possibilities of spread. 



Cooperation is the keynote to success in all great undertakings. 

 (Pardon this trite statement, tritely put!) In this effort to gain 

 a periect knowledge of insects and, through this knowledge, to 

 control them, we are engaged in one of the greatest of all under- 

 takings; and it is not alone for the benefit of our own people — 

 it is for the benefit of humanity. Therefore, in this great effort 

 let us never forget that we must freely urge the help of men work- 

 ing in other branches of science — that we must be keenly on the 

 lookout for points where they can help us — that we must plan 

 our investigations with the idea that others will help, and we 

 must call them in consultation in making our plans. 



