10 PROTECTION OF PLANTS — 1924-25 



a larger population with settled homes and with increase of leisure and of 

 opportunity for taking thought. 



A little more thinking is always in order. It is the prerogative of our species. 

 We get on by thinking upon the ways of nature, and by imitating them under 

 altered conditions that yield better results. Since the human population has 

 almost overtaken the food supply and is ever on the increase, if we would not 

 rob the earth of every remaining element of primeval beauty or potential 

 benefit, it behooves us to be taking thought of better ways for utilizing the part 

 of it that we have already despoiled. We have fields enough for the present, 

 and far too many wastes. In our utilization of plant products there are great 

 losses. Usually, about one part is saved and three parts thrown away. And 

 about in proportion to the richness of its organic content, the part thorwn away 

 becomes a burden of offense. Nature has many agents for the reclamation of 

 these rich wastes, and we may learn to use them to our profit by taking thought. 



The earliest of our betterments consisted in the mechanical treatment of 

 natural products. The devices were very simple; a flat stone for cracking nuts; 

 a hollow stone for pounding acorns; a mortar and pestle for grinding grains. 

 The last was a simple mill, and complicated mills followed afterwards and made 

 bread for our species "the staff of life'. Though we have long been dependent on 

 mills for the preparation of the cereal staples of our diet, we have little consi- 

 dered what mechanical treatment might do by way of preparation of food for 

 some of the lesser organisms. 



It is insects I have in mind: herbivorous insects that are themselves the 

 food of some of our most desirable birds and fishes. I have been directing some 

 experiments in the mechanical preparation of foods for them in the hope of 

 obtaining a more abundant supply of them for feeding purposes; and of the 

 results of these experiments I have come before you to make preliminary report. 



The larvae of certain midges and flies have been the subjects. The midge 

 first use was Chironomus decorus. Larvae of this species hatched from the egg 

 in our aquaria were reared to full naturity on a diet of a single species of pond 

 weed, Potamogeton crispus. This plant is not normally eaten by the larvae, 

 but when its substance was made available by grinding it proved a very satis- 

 factory ration. This work was done by Miss Ruth Tillbury and the details of it 

 were published by her in the Journal of the New York Entomological Society. 



[The speaker here digressed to mention and to illustrate with lantern 

 slides the work done by P. W. Claassen and Miss Hazel E. Branch on utili- 

 zing the larvse of another midge, Chironomus cristatus for clearing out 

 milk wastes in streams. Details of this work have been published in Bulle- 

 tin of the New York State Agricultural Experiment Station.] 



A more extended series of experiments was concerned with providing 

 suitable food for the larvse of the flly, Muscina stahulans. I was drawn into this 

 study by discovering the need of our game bird breeders for suitable insect 



