June 26, 1896.] 



SCIENCE. 



933 



of Massachusetts, together with an account 

 of History and Habits, both in Massachusetts. 

 and Europe. By E. H. Foebush, Field 

 Director, and C. H. Feenald, Entomologist 

 to the State Board of Agriculture. Boston. 

 1896. 



The successive steps in the great experiment 

 in economic entomology which has been car- 

 ried on by the State of Massachusetts during 

 the last five years are admirably portrayed in 

 this volume. Never in the history of this 

 country has so much money been spent by a 

 State or by the General Government in fighting 

 insects as has been used by Massachusetts" 

 against this one species, and it is most fortunate 

 that the work has been in efficient hands and 

 that no political jobbery has been connected with 

 it since its start. Whatever the ultimate result 

 ■of the experiment may be, it cannot fail to have 

 been most instructive as bearing upon future 

 work. The report is an admirable summary of 

 the entire investigation. Mr. Forbush takes 

 up the first half of the volume, some 250 pages, 

 with a history of the gypsy moth in America, 

 carefully detailing year by year the work of the 

 State Commission down to and including the 

 year 1895, following with a chapter on the in- 

 crease and distribution of the insect, another on 

 the methods used for destroying it, another on 

 the influence of birds in the destruction of the 

 species, and a final chapter on the progress of 

 ■extermination. He treats fairly the obstacles 

 to extermination, the principal ones being the 

 enormous reproductive capacity of the moth, its 

 very numerous food plants and the dense popu- 

 lation of the infested region, which increases 

 the danger of local distribution and reinfesta- 

 tion by the constant passing and repassing of 

 infested centers by men and animals. In spite 

 ■of these obstacles, however, Mr. Forbush shows 

 that the insect has been locally exterminated, 

 and argues that with sufficient appropriations it 

 may be generally exterminated. He thinks 

 that the policy of control or extermination of 

 insect pests by government commissions, which 

 has been so successful in certain European 

 countries, njight be applied in this case by the 

 government of the United States. 



The greatest scientific interest attaches to the 

 second part of the report, which has been pre- 



pared by Prof. Fernald. It includes a full biblio- 

 graphy and consideration of the distribution of 

 the species in other countries, the methods used 

 to destroy it abroad, an elaborate account of 

 its life history, based upon the most careful orig- 

 inal observations, a list of the plants upon 

 which the insect has been known to feed in 

 Massachusetts, another list upon which it has 

 been known to feed in Europe, and, by com- 

 parison with these, a very small list of the 

 plants upon which it will not feed. There is 

 further a section on the anatomy of the adult 

 insect and a full consideration of the natural 

 enemies which affect the species both in Europe 

 and in Massachusetts, and the part concludes 

 with an elaborate account of the experiments 

 which have been made with insecticides. 



The portion of the report dealing with the 

 biology of the species contains many sections of 

 much importance. The exact experiments upon 

 the amount of food, on the effects of tempera- 

 ture, on hermaphroditism, on polygamy, on as- 

 sembling and on parthenogenesis are of par- 

 ticular interest. The experiments with insecti- 

 cides show many results which are most sur- 

 prising, and none more so than the feeding of 

 caterpillars, for from five to ten days before 

 causing death, upon leaves treated with strong 

 arsenical solutions. In an interesting by-sub- 

 ject — the dying out of the species in England — • 

 Prof. Fernald advances a new theory. It has 

 been stated by no less an authority than J. 

 Jenner Weir that the gypsy moth has been ex- 

 terminated in England simply by collectors. 

 Prof. Fernald, however, is inclined to think 

 that the darker color of the foliage and other 

 surroundings in England have made the female 

 moths more conspicuous objects to their ene- 

 mies than they are on the continent of Europe, 

 so that in the struggle for existence the species 

 was exterminated before it had time to take on 

 the darker color which would have protected it. 

 The argument is a somewhat elaborate one, and 

 this is simply the conclusion. 



The volume is illustrated with a wealth of 

 text figures and plates, and will forever stand 

 as a monument to the enlightened energy of the 

 State of Massachusetts and the i^ractical and 

 scientific ability of its authors. 



L. O. HOWAED. 



