FORBES: LEPIDOPTERA 553 



tered that we can only touch on the general works: Packard's Guide for the 

 Study of Insects (1870), Berlese's Gli Insetti (1912-1920); Hering's Biologie 

 der Sclimetterlinge (1926), the second volume of Schroeder's Handbuch (fin- 

 ished in 1929), and Bourgogne's chapter on the Lepidoptera in the Traite de 

 Zoologie (1951). 



Economic Entomology 



A review of the history of economic entomology is not a part of this report, 

 but one may note that in this field also the Lepidoptera play a large part. The 

 first serious report was probably Peck's article on the spring cankerworm {Mas- 

 sachusetts Magazine, 1795), which rated a frontispiece. Our century was marked 

 by the inventions of high-pressure spraying apparatus to reach the gypsy cater- 

 pillars in the tall elms of eastern Massachusetts; and the caterpillars still hold 

 their own as test objects, now that economic entomology has gone over from the 

 study of insects to the study of spray chemicals. 



Looking Ahead 



This is a very difficult time to look ahead. One can try to extrapolate the 

 present trends, making allowance for those that will last long and those that 

 are ephemeral, or one may remember that our civilization is more than three 

 quarters through the Petrie cycle, and that the next Dark Century is due in less 

 than two hundred years. 



The first prophecy is that there will be no lack of unknown material to work 

 on. In a few groups, such as the fauna of west and central Europe, or the but- 

 terflies, bombyces, and noctuids of this country, there are few species to add, 

 but in the micros here, and in all groups over most of the earth, even species- 

 making is far from finished. I estimate that we know more than 90 per cent 

 of the micros of Europe, well over half for the United States and Canada, but 

 only a sample (mostly of those that can be easily caught and do not have to be 

 reared) for the rest of the world. 



For geographical study, the general laws of distribution are known, but 

 they have been applied to the Lepidoptera only in a rudimentary way. It is high 

 time for a new "Butterfly Geography" based on the better known groups, such 

 as the butterflies, sphinxes, and saturnids, but usefulness of the other groups must 

 wait for a sounder classification. That sounder classification in turn depends, in 

 the higher forms, chiefly on the more complete study of known characters. The 

 matter of major cleavages, the placing of aberrant types, and especially the evo- 

 lution of the primitive families must wait in turn for mori)hology, and partly 

 for internal morphology. Even in the better known higher types, vastly more 

 study of the early stages is needed. 



For morphology, especially internal morphology, one can find virgin terri- 

 tory anj^vhere in the order; while in comparative physiology and the scientific 

 study of ethology one can say nothing yet has been done. 



The brilliant, well-defined and well-understood pattern characters and the 

 relatively easy breeding of the Lepidoptera make them fine objects for genetics, 

 but so far relatively little has been accomplished. The sex mechanism, the 



