REPORT OF THE ENTOMOLOGIST AND BOTANIST 237 



SESSIONAL PAPER No. 16 



When bought at retail prices these soaps cost from 15 to 20 cents per pound, 

 according to the locality, but, if obtained in large quantities, can be got at from 3 

 to 5 cents per pound. Fifty pound kegs are supplied at 5 cents per pound. Two well 

 known brands of potash soft soaps which have been much used in Canada and have 

 given good satisfaction, are those made by W. H. Owen, of Port Clinton, Ohio, and 

 by Good & Co., of Philadelphia, Pa. If thought desirable, these soaps can be made at 

 home; but it is very unpleasant and dirty work, and it is besides doubtful whether 

 such good or cheap results can be secured as by buying from firms which make a 

 special business of manufacturing soaps with only the required amount of moisture and 

 the proper grade and amount of potash. It has been found in experiments carried on at 

 Washington that what is required for spraying purposes is a caustic potash and fish oil 

 soap, made with a fairly good quality of fish oil and from which water has been elimin- 

 ated by boiling, so that it does not exceed 25 or 30 per cent of the weight of the soap. 

 Soaps made with caustic soda instead of caustic potash are unsuitable for spraying- 

 purposes. Dr. J. B. Smith, in his circular No. 5, * Whale Oil Soap and its Uses,' 

 says : ' Whale oil or fish oil soap is one of the most reliable materials for use against 

 plant-lice, and generally against sucking insects which can be killed by contact insec- 

 ticides. It kills by clogging the spiracles or breathing pores of the insects and also 

 to some extent by its corrosive action. The advantages of fish oil over ordinary laun- 

 dry soap lie in the greater penetrating power, in the fact that it remains liquid when 

 cold at much greater strengths, and that fish oil itself seems to be more fatal to insect 

 life than other animal fats. A good soap can be made as follows : — 



Concentrated potash lye 3 J lbs. 



Water 74 gallons. 



Fish oil 1 gallon. 



Dissolve the lye in boiling water, and to the boiling solution add the fish oil; con- 

 tinue to boil for two hours, and then allow to cool. Any grade of fish oil will answer.' 



The Plum Curculio (Conotrachelus nenuphar, Herbst.). — The Plum Curculio 

 made serious inroads into the sparse crop of plums of 1904. It was complained of in 

 all localities east of and including Ontario, and was perhaps the fruit pest most men- 

 tioned by correspondents. Plums, apricots, cherries and apples were injured. 



The injury of the Plum Curculio is known by sight by thousands of fruit-growers 

 who have never seen the beetle to recognize it as the cause of the injury wKich they 

 know so well on their fruit. The beetle itself (Plate I., figs. 2a and 3) is less than one- 

 fourth of an inch in length, brown and rough, with black and gray mottlings, which give 

 it a remarkable resemblance to a small piece of bark, and make it very difficult to dis- 

 tinguish. There is only one brood of this insect in the year; but perfect insects may 

 be found at all times, because the beetles which emej-ge during August or September 

 of one year, pass the winter as perfect insects under dead leaves, &c., and feed on the 

 buds and leaves of plum trees early in the spring, and later during the season on leaves 

 £,nd fruit of various kinds ; the old insects of the year before may often be collected 

 at the samiC time as the newly emerged brood. When plums are about as large as 

 pease, the crescent-shaped slit, with a small flap containing the egg, may be seen upon 

 them.' The egg hatches soon after, and the white grub (Plate I., fig. 2c) bores into 

 the fruit, so that in ^he case of the plums they soon fall from the tree. The peach, 

 apricot, cherry, apples and pears are also injured, but do not fall from the trees to 

 nearly the same extent as plums. A great many more of the larva? of the Plum Curcu- 

 lio come to full growth in plums than in the other fruits ; the rotting of the fruit 

 seems to be necessary for these grubs to mature. There is no doubt that by far * 

 lai^er number of the grubs become beetles when they have fed in plums and cherries 

 than ir. any other fruit. In apples, to which it causes serious injury also, from the dis- 

 figuring of the fruit, very few larvae mature. By midsummer the larv£E are full 

 grown and burrow a short distance into the ground, where they turn to pupae, and the 

 adult beetles emerge in August. 



