October 16, 1896.] 



SCIENCE. 



543 



accused insects, in the form of an excom- 

 munication which was carried into effect 

 only when the insects disappeared at the 

 time of pupation. 



Lesser, in his ' Insecto-Theology,' pub- 

 lished in London in 1799, says : " We are 

 at this day still almost in the dark with re- 

 gard to those means by which we may de- 

 liver ourselves from the depredations of in- 

 sects. In the Church of Rome recourse 

 has been had to different exorcisms. Other 

 people have fabricated amulets and talis- 

 mans, to which great virtues have been 

 attributed. 



" Whatever credit these means have 

 gained with the people, they are far from 

 having the efficacy of prayer, or the worth 

 of the remedies I am about to prescribe. 



" There are several ways of preventing 

 the increase of insects, the easiest and most 

 natural, in my opinion, are the following : 

 By spreading on the ground ashes mixed 

 with pigeon's or goat's dung, not only in- 

 sects newly come forth, but those about to 

 be hatched are destroyed. By destroying 

 the old ones we rid ourselves of the genera- 

 tion they would have produced, and we 

 thus perform in an instant what we would 

 not fail to have been employed in during 

 the whole course of a year. But should 

 the season anticipate our intentions we 

 must seek their nests in the furrows and 

 clefts of trees. In truth the industry of in- 

 sects in choosing places in which their 

 brood may be in safety makes it impossible, 

 but some of them will escape our search ; 

 but if in one province the country people 

 would use strategems on their part it is 

 certain that they would insure that profit 

 of which they are often frustrated. 



" We cannot defend fruit trees from the 

 ravages of caterpillars better than by care- 

 fully pruning them. By this they acquire 

 much more sap ; and, as these insects are 

 not fond of too abundant juice, they seek 



elsewhere a food more to their taste. If 

 the approach of winter obliges them to 

 gather together in the nests which they 

 form at the extremities of the branches 

 they must be taken off before the spring 

 has made any progress. 



" It is possible that these means may not 

 be practicable at all times ; but then other 

 strategems must be fallen upon to stifle the 

 evil in its birth. If caterpillars, ants and 

 other insects roam over the ground, and 

 have not yet got upon the trees they are in 

 search of, a stratum of ashes or of chalk 

 must be laid at the bottom, which will ob- 

 struct their passage. I believe this to be 

 infallible ; for, besides that they are ene- 

 mies to all constraint, they would be so 

 embarrassed by these substances that they 

 would not be able to disengage themselves. 

 Twisted straw, clay, wool and cotton are 

 likewise successful obstacles to their as- 

 cent. Circles of them are put around the 

 stem of the tree, and, if a little resinous 

 substance is added to them, the tree will be 

 out of danger. Let us change the case : 

 suppose the insects have already gotten 

 upon the trees, plants and bushes, the hand 

 must be employed. But there are some 

 times when this is done with greater suc- 

 cess than at others, as in the morning, the 

 evening and during rain. These times are 

 preferable to any part of the day, because 

 coolness and humidity cause insects to col- 

 lect together, and then they form heaps 

 which may be crushed at once. If, more- 

 over, they have gained the top, and the 

 height prevents their being reached with 

 the hand, the tree must be shaken, or a 

 pole, with rags on the end of it, employed 

 to sweep them off. But expedients must 

 be suggested by circumstances. Another 

 snare, the success of which is not less 

 happy, for securing fruit trees is to lay the 

 trunk over with glue, etc." 



This represents fairly well the status of 

 economic entomology at the end of the 



