NATURE 



197 



THURSDAY, JULY 11, 1S72 



ECONOMIC ENTOMOLOGY 



WE have more than once had occasion to refer 

 to the zeal with which the investigation of the 

 insect pests so destructive to our crops of roots and 

 fruits is carried on on the other side of the Atlantic. 

 Three publications now lying before us — two from the 

 United States, and one from Canada — furnish a text 

 for a few further remarks on this subject. They are : 

 " Fourth Annual Report of the Noxious, Beneficial, and 

 other Insects of the State of Missouri," by Charles V. 

 Riley, State Entomologist ; " Second Annual Report on 

 the Injurious and Beneficial Insects of Massachusetts." 

 by A. S. Packard, Jan., M.U. ; and " Report of the En- 

 tomological Society of the Province of Ontario for the 

 year 1871." These are all official publications ; the two 

 first being Reports made to the State Boards of Agricul- 

 ture ; the last printed by order of the Legislative As- 

 sembly. They represent the result of investigations made 

 at the expense of the citizens of the respective States or 

 Province, who arc willing to tax themselves in order that 

 the highest scientific experience at their command may be 

 brought to bear on researches whose object is the mate- 

 rial improvement of the resources of their country. The 

 only similar efforts to which we can point in this country 

 are the result of private enterprise. The Royal Agricul- 

 tural Society has long engaged the services of a chemist 

 to analyse manures and feeding-stuffs, and we recorded 

 not long since the addition to its staff of a consulting 

 botanist, and its intention to appoint also a consulting en- 

 tomologist ; but their investigations are carried on exclu- 

 sively for the benefit of the members of their Society. The 

 Royal Horticultural Society has also arranged for a course 

 of lectures on Economic Entomology, and last year in- 

 vited competition for prizes for collections of insects to 

 illustrate this subject. 



\Ye have so often expressed our view on the relative 

 advantage of having these investigations carried on by 

 private enterprise, or under the direction of the State, 

 that it is needless to repeat it here. Dr. Packard thus 

 forcibly advocates the latter alternative, referring to i\I. 

 Pasteur's labours in endeavouring to mitigate the scourge 

 of the /i V;/ /«t- in the South of France : — "It should be 

 remembered that this remarkable result is due primarily 

 to the most abstruse researches upon microscopic plants 

 by specialists, for the pure love of science. Their cloister 

 studies, put to practical account, save the destruction 

 of one of the largest agricultural industries in Southern 

 Lurope. In like manner, had the general Government or 

 individual States encouraged the botanist and entomolo- 

 gist in their studies, and caused them to be turned to 

 practical accounts, we should not have had to give up the 

 cultivation of wheat in the northernmost States ; our cot- 

 ton crop would perhaps have been doubled ; and our 

 garden and field crops have regularly yielded a steady 

 return to the producer." It must be recollected that the 

 Federal Government at \Yashington is now spending 

 large sums in the compilation and printing of enormous 

 numbers of the Monthly Agricultural Reports, in addition 

 to the money devoted by the separate States. 



VOL. VI. 



Mr. Riley's Report is one of a series, of which we have 

 already noticed its immediate predecessor, and is a 

 pamphlet of 150 pages, containing, independently of its 

 special object, no small amount of valuable information 

 of general interest. The higher the summer temperature, 

 the greater appears to be the variety of the foes against 

 which the agriculturist has to contend ; and their number 

 in the south-western of the United States is legion. After 

 discussing the various insect-enemies to the potato, the 

 cabbage, the apple, the walnut, the grape-vine, and other 

 crops, the causes of their appearance, and the best anti- 

 dotes artificial or natural, the greater portion of ]Mr. 

 Riley's Report is devoted to the Silkworm, on the cultiva- 

 tion of which he has bestowed great attention. He 

 describes the various kinds of silkworm, their mode 

 of cultivation, their food in the larva, and imago 

 conditions, and the various enemies, parasitic and 

 others, to which they are subject ; and this portion 

 of the Report is illustrated by a number of very well- 

 e.xecuted wood engravings. The practical i-esults are 

 thus summed up : — '' There can be no good reason why 

 silk-culture may not become one of the industries of this 

 country, or of our State, especially if fostered at the 

 start. I would, however, advise no one to enter into it 

 on a large scale as a business. The raising of silk is 

 seldom lucrative even in the most favourable countries ; 

 for in this, as in most other industries, the principal pro- 

 fits accrue to the middle men, reelers, and manufacturers ; 

 but on a small scale, and prosecuted in connection with 

 other branches of agriculture and horticulture, it will give 

 the most desirable returns for the time employed. The 

 erection of a few reeling establishments is absolutely 

 necessary to establish this industry." 



Dr. Packard's Report treats of similar matters in a 

 similar scientific spirit. It is interesting to note the reci- 

 procity of indebtedness between this country and America 

 in the matter of insect pests ; we have received from them 

 the Pliylloxera vastatrix, so destructive to our vines ; and 

 have given them as a set-off our white cabbage butterfly, 

 the Picris rapa, first introduced into the United Stales 

 fifteen years since, and now spreading every year with 

 terrible rapidity. It is curious that the chief check on the 

 increase of the larva is a native, not an imported parasite, 

 the Ptcroinalus puparuin. 



The Canadian Report is interesting, as being the result 

 of the first appropriation of money for these purposes, as 

 far as we are aware, by any of our American colonies. 

 The Entomological Society of Ontario is subsidised by the 

 Legislative Assembly, in order to encourage the devotion 

 of its labours to inquiries of a practical character for the 

 benefit of the colony. The present Report, of nearly 100 

 closely [irinted pages, well illustrated with woodcuts, gives 

 promise of much useful work. The Report is divided into 

 sections relating to insects injurious to the apple, grape, 

 plum, currant and gooseberry, wheat crops, potato, cabbage, 

 and cucumber tribe, by different competent members of the 

 Society. 



We have referred to these Reports in order to draw 

 from them a lesson as to the direction of the labours of 

 our botanists and entomologists at home. We have 

 among us at least as high scientific talent in these 

 branches as in the United States ; but, with a few rare 

 exceptions, this talent is not devoted to researches which 



