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wise make of his potato patch, his cotton field or his phim orchard a nuisance nursery 

 from which no indiistr3f could protect the surrounding farms. 



Thus, then, the organization necessary for a successful campaign against our insect 

 enemies must be authoritatively demanded by you. Under less free forms of government 

 the plan which I haxc suggested would piohably have long ago been perfected by the 

 rulers. Even the fear of the extension of the Colorado Potato Beetle to Europe has ex- 

 cited in several countries almost as much discussion and confusion of counsel as an apjire- 

 hended revolution. 



Tiie fact is, that these incursions and ra\uges of hostile insects represent a condition 

 of ifur. It is only by a 5?;rt.s/-military organization and approjniate weapons suited to the 

 nature of the enemy that they can be conquered. Without recognition of this fact no- 

 thing can be done against them, and we must bow our heads and exclaim with the pious 

 Mohammedan fatalist, " It is the vcill of God." 



Three subjects yet remain to be considered — the materials to be used, the time of 

 making the attack in force, and the weapons to be employed. 



1. The materials may be either vegetable or mineral, or merely human labour intelli- 

 gently and persistently applied. The latter is the only effective means of contending 

 against some insects, but in all cases -it is a necessary adjunct to the remedies used. 

 These remedies are very numerous, and until a careful investigation is made of the large 

 number already suggested, no j.roper indications can be given except that those least in- 

 jurious to man should be jireferred, even at greater cost of money and labour ; and that 

 those which kill the insect by contact with its body are likely to prove more effectual 

 than those which destroy by poisoning its food. It may be here observed that the form of 

 api)aratus in these two cases must be quite different. In the latter, any contrivance which 

 will sprinkle a fluid or dust a powder on the exposed or upper surfivce of the leaves will 

 be sufficient ; in the former, in which tae poison kills by contact with the insect, it must 

 be able to reach the enemy wherever .sheltered. 



2. The time of attack must naturally be when the enemy is least able to resist. To 

 quot(- again from the excellent memoir of Motscliulsky, " the most effective and at the 

 same time the easiest mode of opposing the development of the locusts is the crushing out 

 of the young broods when collected in swarms in the place where tliey are hatched. Con- 

 sequently the most important thing is to know the nesting place of these destructive.pests. 

 In order to discover them and to point out the course to be pursued, * * it 

 might be well to send skilful persons * * to make the necessary researches, 

 and these, with the assistance of the local authorities, might seek out the places where the 

 insects abound, and establish the necessary regulations for their destruction." (1. c. p. 228.) 

 In the case of the cotton moth it is plain that the attack should be made upon the earliest 

 broods, which are said to appear in the extreme southern part of the country, and from 

 which the migratory swarms which travel northward are supposed to be developed ; also, 

 that the attack must be directed against the caterpillars rather than the perfect insects. 



The Colorado Potato Beetle may also be attacked with greatest success in the larval 

 state. The integuments are then soft, anil the appetite more voracious, so that whether 

 the poison by contact or the poison by food be used, it will have a more certain effect 

 than upon the perfect insect, which is protected against the former by the hard chitinous 

 surface, and against the latter by preoccupation in reproductive duties. 



You will be prepared to admit the imjiortance of the recommendation above made, 

 tRat the times for making the attack should be directed by the Scientific Commission after 

 full examination of the habits of the insects and the dates of their appearance in their 

 various stages of development. These dates will vary in different districts, and without a 

 carefully tabulated calendar of the necessary facts, no system of combined effort, such 

 as I believe to be essential, can be planncid. 



The apparatus to be used must of course vary greatly with the habits of the insects 

 to be attacked. In the case of the jjlum curculio, canvas frames propelled on a kind of 

 wheelbarrow, with a ram to concuss the trunk of the tree, is probably the best instrument 

 yet devised. The insect will fall into the net when the tree is struck, and may be easily 

 destroyed when a sufficient mass has been collected. For the cotton moth and the 

 potato beetle the apjjaratus for poisoning the leaves upon which they feed may be an)' 

 simple sprinkler or dusting box, according as liquid or solid jmison is employed. But for 



