Insecticides 



(442 ) 



Insects 



INSECTICIDES. 



In his struggles against insect foes (he gardener 

 has to depend largely upon the aid of various 

 compounds, which experience lias shown to be 

 inimical to insect life, and which can, moreover, 

 be used at. a strength sufficient to kill the insects 

 without endangering the life of the plants. Insect- 

 icides may be divided into three sections : (a) 

 vaporisers, (b) powders, (c) liquids. Amongst the 

 \aporisers tobacco plays a most important part. 

 Not many years ago the burning of tobacco, 

 tobacco paper, or tobacco rag was very commonly 

 practised. Science has, however, found a method 

 of liberating nicotine fumes in a more concen- 

 trated form. A still evening or early morning 

 should be chosen. It is a wasteful practice to 

 attempt to fumigate a house when even a moderate 

 wind is blowing. Again, the rays of the sun pour- 

 ing down on a closely shut up house for several 

 hours raise the temperature within to a degree 

 inimical to the health of the plants. Plants and 

 houses which are to be fumigated should be as dry 

 as possible. 



Insecticides in the powder form are also in 

 common use. They include tobacco powder, 

 Hellebore powder, and flowers of sulphur, and they 

 are best applied by means of a small blower or 

 bellows, specially constructed, such as the Malbec. 

 The leaves of Pyrethrum roseum and P. cinerari- 

 folium are the base of a powder that is in common 

 domestic use, but which is also effective when 

 employed upon plants. For window plants, where 

 only small quantities are required, ordinary snuff 

 makes a capital insecticide. Flowers of sulphur is 

 more commonly used as a fungicide, but insects do 

 not like it. 



All insecticides in the powder form should be 

 syringed off the plants within a few hours of their 

 application. This is especially to be noted in the 

 case of Hellebore powder, which is a deadly 

 poison, but which is one of the most effective 

 weapons to use against the troublesome Goose- 

 berry caterpillar. Tobacco powder is most com- 

 monly used for dusting in the points of the shoots 

 of Chrysanthemums, Carnations, etc., that are 

 attacked by green or black fly. If not washed out 

 it injures the young, tender leaves. 



Nowhere has the ingenuity of the gardener been 

 displayed to better advantage than in the making 

 of the numerous insecticides that are applied in 

 li<iuid form. Not content with the various excel- 

 lent proprietary preparations which. are available, 

 he has various recipes for making insect-killing 

 mixtures at home. Of proprietary insecticides 

 that may be said to have a world-wide fame, Fir- 

 tree Oil, Lemon Oil, Gishurst Compound, and 

 Nicotine Soap may be named. 



Petroleum, popularly but erroneously called 

 paraffin, is the sheet anchor of the home maker of 

 insecticides. Unfortunately, it is not soluble in 

 water, and needs some greasy matter, such as soft 

 soap, to act as a vehicle for it. 



A few recipes for home-made insecticides are 

 given below : 



Kerosene Emulsion. One pound of soft soap, 

 1 quart of soft water. Boil for half an hour. Take 

 off the fire, add i pint of petroleum ; stir briskly. 

 Add 8 gallons of water, churn with a syringe, and 

 apply. This is effective against American Blight, 

 black and green fly, red spider, Celery fly, and 

 Onion fly. 



An Ordinary Wash for Pot Plants. Two ounces 



of soft soap in 1 gallon of soft water. Use warm. 

 This is useful for sponging Camellias, Indiarubber 

 Plants, Aspidistras, etc. 



Lime Wash. Eight pounds of lime, 1 Ib. of soft 

 soap, 4 gallons of water, 2 oz. of size. This may 

 be painted on the stems of fruit trees. 



Paris Green. One ounce of Paris Green paste, 

 4 oz. of soft soap, 20 gallons of water. Mix 

 thoroughly, and keep constantly stirred. This is 

 effective for Codlin Moth and Winter Moth cater- 

 pillars. Although it is a poison (an arsenical 

 compound), and fruit growers are prejudiced 

 against it on this account, no harm will result if 

 the above quantities are used, and the mixture is 

 kept constantly agitated during application. Apply 

 just after the flowers have set, with a spraying- 

 machine. It should not be used when the fruit is 

 getting mature. 



Tobacco Water. Four ounces of tobacco, 1 gallon 

 of water. Apply warm with a sponge or syringe. 

 Two ounces of soft soap may be added. Good for 

 sucking insects. 



A Winter Dressing for Fruit Trees. Half a pound 

 of caustic soda (Greenbank's 98 per cent.), f Ib. 

 of commercial potash, 5 gallons of water. Spray ; 

 but keep off the clothes. This destroys moss and 

 lichen as well as the insects they harbour. 



(Juans'ia Solution. One pound of Quassia chips, 

 10 gallons of water, soaked for ten hours. Half a 

 pound of soft soap may be added if desired, but 

 this should be boiled in the water. Useful for 

 black and green fly on any plants. It renders the 

 plants distasteful to the fly, but does not kill the 

 latter. Apply warm. 



The Simplest Insecticide. Hot water (132 

 temperature). Very few plants are in mred by 

 water at this temperature, and it has the advantage, 

 besides its cheapness, of not clogging up the pores 

 of the leaves. 



Application of Insecticides. An ordinary garden 

 syringe suffices in most instances ; but the Abol 

 syringe and sprayer may be used where a very fine 

 spray is desired*. For fruit trees special engines 

 are made, and some of them have an arrangement 

 whereby the working of the pump sets in motion a 

 set of churners inside.. This is important where 

 such substances as Paris Green are being em- 

 ployed. For the more 'costly insecticides, such as 

 Lemon Oil, dipping is the most economical method. 

 A wooden vessel is preferable to a metal one. 

 After use the liquid may be strained through fine 

 muslin to remove the' dirt, and botiled up for 

 further use. 



All insecticides are more efficacious if applied 

 warm than cold. 



INSECTS. 



Frequently the term " insect " is applied to all 

 animals which have bodies exhibiting a row of 

 joints. Thus woodlice, centipedes, spiders, mites, 

 crabs, and even worms are included. Strictly 

 speaking, however, insects are () animals possess- 

 ing a jointed body, formed in three principal divi- 

 sions, viz. the head, with its antenna? or feelers, the 

 thorax, and the abdomen ; (ft) which breathe not by 

 lungs, but by long tubes (tracheie) running through 

 the body and limbs ; (c) and which during their life 

 history pass through a series of changes. These 

 stages may be named as follows : (1) the egg ; (2) the 

 larva or caterpillar ; (3) the pupa ; (4) the perfect 

 insect, imago, or egg layer. Usually it is in the larval 



