1044 DISEASES AND INSECTS 



DISEASES AND INSECTS 



then set upon coals. This is a desirable way of dealing with mos- 

 quitos and flies. 



(5) In alcohol, (a) Put a part of pyrethrum (buhach) and four 

 parts alcohol, by weight, in any tight vessel. Shake occasionally, 

 and after eight days filter. Apply with an atomizer. Excellent for 

 greenhouse pests. For some plants it needs to be diluted a little. 

 (6) Dissolve about four ounces of powder in one gill of alcohol, and 

 add twelve gallons of water. 



(6) Decoction. Whole flower-heads are treated to boiling 

 water, and the liquid is covered to prevent evaporation. Boiling 

 the liquid destroys its value. 



Good insect-powder can be made from Pyrethrum roseum, and 

 probably also from P. cinerarise folium, grown in the home garden. 



1323. Device for discharging the cyanide into the acid. 



Bait, vegetable bait. Spray a patch of clover or some other 

 plant that the insects will eat with paris green or some other 

 arsenical; mow it close to the ground, and while fresh place it in 

 small piles round the infested plants. To avoid wilting of the bait, 

 cover the heaps with a shingle or piece of board. 



Bran-arsenic mash. White arsenic, one-half pound, or paris 

 green, one pound; bran, fifty pounds. Mix thoroughly and then 

 add enough water to make a wet mash. Sugar or molasses may be 

 added, but is unnecessary. Poisoned baits are used against cut- 

 worms and grasshoppers. 



Kansas grasshopper bait. This bait is the most efficient means 

 of controlling grasshoppers yet devised. It is prepared as follows: 

 Bran, twenty pounds; paris green, one pound; syrup, two quarts; 

 oranges or lemons, three fruits; water, three and one-half gallons. 

 Mix the bran and paris green thoroughly in a wash-tub while dry. 

 Squeeze the juice of the oranges or lemons into the water; chop the 

 pulp and peel fine and add them also. Dissolve the syrup in the 

 water and wet the bran and poison with the mixture, stirring at 

 the same time so as to dampen the mash thoroughly. Sow the bait 

 broadcast in the infested area early in the morning. 



Criddle mixture. Mix one pound of paris green with one-half 

 barrel of horse droppings, and add one pound of salt if the material 

 is not fresh. For use against grasshoppers. 



Gas tar is used extensively for painting wounds to keep 

 out the moisture and prevent the entrance of insects. It is 

 also sometimes used on peach trees to keep out the borers. 

 In this case it should be applied in the spring only, as there 

 is danger of injuring the trees in the fall. 



Asphalt. Certain grades of asphalt have been used 

 successfully on peach in California to keep out the Pacific 

 peach tree-borer. Experiments in the eastern states indi- 

 cate that it may be used to advantage against the common 

 peach tree-borer. 



Hot-water. Submerge affected plants or branches in 

 water at a temperature of about 125. For aphis. It will 

 also kill rose-bugs at a temperature of 125 to 135. 



Gasolene torch. The gasolene torch has been success- 

 fully used for the control of scale insects on date palms in 

 Arizona. The trees are first pruned closely, drenched with 



fasolene and fired. They are then scorched with a gasolene 

 last torch. 



Flour paste. Mix a cheap grade of wheat flour with cold 

 water, making a thin batter, without lumps; or wash the 

 flour through a wire screen with a stream of cold water. 

 Dilute until there is one pound of flour in each gallon of 

 mixture. Cook until a paste is formed, stirring constantly 

 to prevent caking or burning. Add sufficient water to 

 make up for evaporation. For use, add eight gallons of 

 this stock solution to one hundred gallons of water. Used 

 for red spider in California. 



General practices. 



Cleanliness. Much can be done to check the ravages of 

 insects by destroying their breeding-places and hiding- 

 places. Weeds, rubbish, and refuse should be eliminated. 



Hand-picking is often still the best means of destroying '. 

 insects despite all the perfection of machinery and of ma- 

 terials. This is, particularly true about the home grounds and 

 in the garden. The cultivator should not scorn this method. 



Promoting growth. Any course that tends to promote 

 vigor will be helpful in enabling plants to withstand the 

 attacks of plant-lice and other insects. 



Burning. Larvae which live or feed in webs, like the tent- 

 caterpillar and fall web-worm may be burned with a torch. The 

 lamp or torch used in campaign parades finds its most efficient 

 use here. 



Banding. To prevent the ascent of canker-worm moths and 

 gypsy-moth caterpillars, various forms of sticky bands are in use. 

 For this purpose there is no better substance than "tree tangle- 

 foot." It may be applied directly to the tree-trunk, but when so 

 used leaves an unsightly mark and requires more material than 

 when the following method is used : First place a strip of cotton 

 batting 3 inches wide around the trunk; cover this with a strip 

 of tarred paper 5 inches wide; draw the paper tight and fasten at 

 the lap only with three or four tacks. Spread the tanglefoot on the 

 upper two-thirds of the paper, and comb it from time to time to 

 keep the surface sticky. Burlap bands are made by tying or tack- 

 ing a strip of burlap around the trunk and letting the edges hang 

 down. The larvse will hide under the loose edge, where they may be 

 killed. Banding is now little used for codlin-moth, since spraying 

 with poison has been found so much more effective. 



Fumigation. 



Poisonous gases are widely used in killing insects 

 under certain conditions. Hydrocyanic acid gas is 

 employed in the fumigation of greenhouses and citrus 

 trees. It is a most deadly and effective material. In 

 Europe, fumigation with this gas is known as cyaniding 

 and cyanization. Nicotine preparations are used ex- 

 tensively in greenhouse fumigation. Carbon bisulfid 

 is employed almost exclusively for the treatment of 

 stored grains and seeds. 



Hydrocyanic acid gas. This gas is generated by 

 adding potassium or sodium cyanide to dilute sulfuric 

 acid. The gas is a deadly poison, and great care should 

 be taken not to inhale it. One breath is fatal ! 



Potassium cyanide is a white amorphous salt that 

 readily absorbs moisture when exposed to the air. 

 Pure potassium cyanide contains 40 per cent of cyano- 

 gen (CN) by weight. When potassium cyanide (KCN) 

 is placed in dilute sulfuric acid the cyanogen (CN) 

 unites with the hydrogen (H) of the acid (H 2 SO 4 ) to 

 form hydrocyanic acid gas (HCN). In the preparation 

 of this gas for fumigation purposes use a potassium- 

 cyanide which is at least 98 per cent pure. The chemi- 

 cals should always be combined in the following pro- 

 portions: Potassium cyanide, one ounce; sulfuric acid, 

 one fluid ounce; water, three fluid ounces. 



Always use an earthen dish, pour in the water first, 

 and add the sulfuric acid. When all is ready, drop in 

 the proper quantity of potassium cyanide and retire 



t 4-'x 6' 



f. 



DOOR 4-VSj 



SECTION or DOOR. 



1324. Shed for the fumigation of nursery stock. 



