ENTOMOLOGICAL SOCIETY OF ONTARIO. 71 



The females are largei", varying from one and a half to two and a half inches between 

 the tips of the wings ; the entire body is white, except the abdomen beneath and the 

 tip above, which are yellow. The markings on the fore wings are dark brown, or nearly 

 black, but in some specimens are almost obliterated. The figures shown herewith have 

 been kindly lent by Prof. Forbush, and give the general appearance of the markings of 

 the two sexes, the chrysalis and the caterpillar. 



The methods which have been adopted in the prosecution of such extensive opera- 

 tions as have been necessary, have been changed from time to time according to circum- 

 stances and experience, and many valuable data have been recorded which will be of great 

 assistance for reference in future work. For carrying on this warfare, it was necessary 

 to train all the inspectors and the many men required to cover the ground, and to attend 

 to the many details connected with the destruction of the insect in its various stages, 

 and the prevention of its spread into other districts. This involved an immense amount 

 of careful work, which naturally took much time and money. A small hand-book, 

 entitled " Laws, Rules and Regulations relating to the extermination of the Gypsy Moth," 

 was printed for the use of the employees, giving a copy of the Act of 1891, authorizing 

 the work, " Rules and Regulations for the Public," most complete " Rules and Regulations 

 for the Agents " employed, and finally a very complete but concise account of the 

 life history and habits of the Gypsy moth. 



The methods employed were briefly as follows : The destruction of the egg was 

 effected by saturating the clusters with creosote oil, dilute nitric and carbolic acids. 

 For the caterpillars, trees were banded with burlap, which provided a hiding place in 

 which they were afterwards destroyed ; or a material called " raupenleim " or " insect 

 lime," was placed upon the bands to prevent the caterpillars from climbing trees. Under- 

 brush was cleared out wherever possible, and useless and hollow trees which would 

 form hiding places, were cut down and burnt. Traps were also devised in which females 

 were enclosed for the attraction of the males, which were successful. Wherever possible, 

 shade trees, orchards and woodlands were sprayed with poisonous mixtures. As it was 

 known that the moths were disseminated mainly by vehicles driving beneath trees in 

 infested centres, efforts were made to inspect all vehicles going out of such districts and 

 to clear thoroughly all trees along the roads. Great care seems to have been taken to 

 obtain an accurate knowledge of the extent of the infested territory. Prof. Forbush, 

 in his 1894 report, says: "The means, which though expensive, have given the best 

 results and have finally exterminated the moth from localities and towns, consist of a 

 thorough long- continued and repeated search by competent men, not only of all known 

 infested localities, but of entire towns. The moth is now so rare in most of the infested 

 towns that it is only by such search that it can be found, and this search must be relied 

 upon to assure extermination. When a colony is found, all forms of the moth must be 

 destroyed ; loose bark must be scraped from the trees, the undergrowth cut and burnt, 

 all cavities which may serve for hiding places filled, and the locality carefully watched 

 for at least two yeais." 



Among the good results of this investigation is the discovery of the value of Arsenate 

 of Lead as an insecticide. The experiments with insecticides made under Prof. Fernald's 

 direction, prove that the arsenites as commonly used for spraying foliage are comparatively 

 ineffectual against the Gypsy moth. It was found that the caterpillars will feed for days 

 without apparent injury, upon trees which have been sprayed with Paris green or London 

 purple, in a mixture so strong as to somewhat burn the leaves. In fact, the committee, 

 in the spraying they are carrying on at present, have found it necessary to use arsenate 

 of lead in as strong proportion as 10 pounds to 150 gallons of water. The great value of 

 arsenate of lead is that it can be used freely upon foliage without danger of injury to the 

 plant, as is the case with the generally used arsenites, Paris green and London purple. 

 The greatest success in clearing the infested districts seems to have been secured by 

 destroying the eggs late in the summer and in early fall, as soon as possible after tliey are 

 deposited. If they are not disposed of at this time, some of the egg-clusters may be broken, 

 and the eggs scattered by man, animals, or the elements. The treatment with acids is 

 preferable to collecting, as there is less danger of breaking up the clusters and dropping 



