ENTOMOLOGICAL SOCIETY OF ONTARIO. 19 



(Figs. 2 and 3) which lays its eggs in the forming flower heads of the clover plant 

 in May or early in June and again during July. There are thus two broods of this 

 insect in a season. The larvje (Fig. 4) of the first brood attain their full growth 

 about the end (i June, when they leave the clover heads and go into the ground a &hort 

 distance to complete their transformations, the perfect flies appearing about the middle 

 of July. Ihe eggs laid by these midges produce the second brood of larvae which destroy 

 the fall crop of clover seed. Part of this brood matures in September, but the re- 

 mainder not until the following spring. Experience has taught farmers that the remedy 

 suggested of feeding otf their clover fields with cattle and sheep until the 

 beginning or middle of June, or cutting it by the 20th of the same month, 

 is the only way to secure an autumn crop of seed ; thus, the grubs of 

 this first brood (the eggs of which wt^re deposited on the growing clover 

 as the heads formed) are destroyed by the cattle eating them, or they dry 

 up with the clover hay which has been cut before they were mature enough 

 to leave the heads of clover and go into the ground to complete their 

 stages. If the clover is left standing in the fields till the end of June, 

 a sufficient time elapses for this latter process to take place, and the per- 

 fect flies emerge again just in time to lay their eggs in the opening flowers 

 of the second crop. In this way, the seed of the second crop is destroyed 

 as well as the first. 



Few appreciate the fact that many of the common remedies which have 

 now come to be pretty generally practised all over Canada, were the out- 

 come of much labour and unremitting attention on the part of men who 

 had devoted years of close study to the matter. The farmer who saves 

 his crop of potatoes by dusting or sprinkling them with a mixture contain- 

 F'g- 4- ing Paris green, has small thought for the contiuaous effort and numerous 



trials which were necessary before the insecticidal properties of this useful substance were 

 diacovereJ. Paris green, the standard remedy against all mandibulate or biting insects, 

 is a chemical combination containing chiefly arsenic and copper, about 60 per cent, of it 

 being arsenic. It is to this latter it owes most of its virtue as an insecticide. It is, I 

 think, almost an ideal material for the purposes to which it is applied by entomologists. The 

 danger of its being mistaken for some other substance of a harmless nature is reduced to 

 a minimum by its characteristic bright green colour, the colour green being very generally 

 recognized as indicative of poisonous properties. Its insolubility in water and under 

 niOHt conditions to which it is likely to be exposed, renders its use very simple, although 

 thi.s fact also necessitates the constant agitation, during their application, of all liquid 

 mixtures containing ic, in order that the Paris green, which is very heavy, may be kept in 

 suspension uniformly through the whole liquid. Its fine state of division makes its 

 dilution either with liquids or dry powders very easy, and its extreme virulence as a poison 

 makes it possible to dilute it very much indeed without los.s of its efficacy as an insecti- 

 cide. It h.s been discovered of late years that, by mixing an equal weight of quick-lime 

 with thisarsenite, the caubtic efl"ect8 which sometimes follow its careless use on vegetation, 

 can be in a large measure prevented. This discovery has simplified immensely the 

 question of the most suitable remedy for mandibulate insects ; for now a standard strength 

 of one pound of Paris grein, one pound of quick-lime and 200 gallons of water may be 

 recommended for use on all kinds of vegetation. If it be thought more convenient to 

 app'y the poi.son in a dry form, it may be mixed with fifty times its quantity of any dry 

 and finely di\'4ided powder. 



The easiest way of applying Paris green to orchard trees is in a liquid mixture, by 

 means of a force pump with a spraying nozzle. The good results which have followed 

 the adoption of spraying as a regular orchard operation, have been so remarkable that it 

 is now practised by all progressivn fruit growers. There are various kinds of spraying 



* Kig 2a repretents the male mid^e enormously m»gai6ed ; 6, »he head, and c, the peculiar clamping 

 organ-i still farther magnified ; d, the j lints of the antennse ; e. the clawa ; f f, forms of the scalei^ which 

 are dmtriliuted over the wintfs an i btdy. Fig. 3a, represeuts the female midge similarly magnified ; 6, 

 the head ; c, the tip of the ovipo-itor ; d, a portion of one of the antennae. The small lines beside 

 the tigiirex give the natu-al bizh ot th-< midge. Fi<. 4a, represents the larva ; 6, the head withdrawn 

 into the first segment. These figures -^re from drawings by the late Prof. C. V. Kiley, 



