SPRAYS AND OTHER MEANS OF CONTROL 



1861 



prove unsatisfactory. It is, therefore, ttie 

 aim to include only those preparations 

 which are known to give definite and re- 

 liable results. 



In general, insecticidal sprays and pow- 

 ders are listed in three main classes, viz.: 

 poison sprays, contact sprays and repel- 

 lents. The poison sprays are used in 

 controlling biting and chewing insects 

 which are capable of taking the poison 

 internally; while the contact sprays are 

 for piercing and sucking insects which 

 cannot be controlled by poison sprays. 

 The repellents do not kill, but, applied to 

 the plants or soils, serve to drive the pests 

 away and thus prevent attacks. 



A number of the contact insecticides 

 are also fungicides and some of the fun- 

 gicides are insect repellents. 



POISON IIVSECTICIDE FOR CHEWING 

 INSECTS 



Poisoned sprays are usually made of 

 arsenical compounds, and are therefore 

 known as arsenical sprays, or insecticides. 

 Formerly Paris green and London purple 

 were used, but of late years it has been 

 found that lead arsenate and zinc arsen- 

 ite are as efficient, cheaper and do less 

 damage to the fruit and foliage. 



These sprays are used in combatting 

 leaf-eating insects, such as grasshoppers, 

 army and cut worms, tent caterpillars, 

 red-humped caterpillars, tomato and to- 

 bacco worms, cabbage worms, pear slugs, 

 beetles, etc. 



Arsenate of Lead 

 (1) 



Arsenate of lead (poison) lib. 



Water .^0 gals. 



For newly hatched insects it is not 

 necessary to use It stronger. For old 

 or large insects use double the quantity. 

 Mix the paste well with a small amount 

 of water. Powdered arsenate of lead is 

 about twice as strong as the paste. Do 

 not use arsenate that settles quickly or 

 feels gritty. Agitate while spraying. 



Arsenite of zinc powdered is about 

 four times as strong as paste lead. It 

 may scorch in a damp season. 



Arsenate of lead 4 lbs. 



Water 100 gais. 



It is better to purchase arsenate of 

 lead than to attempt to make it. In 

 mixing, preparatory to spraying, the 

 amount of arsenate of lead for each spray 



tank full should be worked into a very 

 thin paste having the appearance of milk 

 of lime. It should never be thrown as 

 a mass into the spray tank. This is the 

 standard spray for codling moth and 

 other eating insects. It is possible, how- 

 ever, that we shall use arsenite of zinc 

 in the future. 



O'Gaba 



Arsenate of Lead and Bordeaux Mixture 



It is often desirable to use a combin- 

 ation arsenical spray with a fungicide 

 for scab and codling moth. With Bor- 

 deaux mixture use four pounds of ar- 

 senate of lead to one hundred gallons of 

 the preparation when ready to apply 

 to the trees. 



Lead Arsenate and Lime-Sulphur 



A combination arsenical and fungicid- 

 al spray may also be made by adding 

 five pounds of arsenate of lead to every 

 100 gallons of the lime-sulphur after it 

 is properly diluted for spraying. 



EssiQ 

 Bordeaux 

 (1) 



Bluestone 6 lbs. 



Oood lime 6 lbs. 



Water .50 sals. 



Dissolve the bluestone by suspending 

 it in a sack in 25 gallons of water in 

 a barrel. Slake the lime in another ves- 

 sel, adding a little water slowly, and di- 

 lute to 25 gallons. Mix the two thorough- 

 ly. Even the best Bordeaux may scorch 

 in rainy weather. 



O'Gara 

 (2) 



Bluestone lbs. 



CJood lime 4 lbs. 



Water 50 gals. 



Dissolve the bluestone by suspending 

 it in a sack in 25 gallons of water in a 

 barrel. Slake the lime in another vessel, 

 adding a little water slowly, and dilute 

 to 25 gallons. Mix the two thoroughly. 

 Even the best Bordeaux may scorch in 

 rainy weather. 



For double strength Bordeaux use 

 twice as much bluestone and lime. 



This is the standard fall spray for 

 apples and stone fruits. 



W. S. C. 

 (3) 



Bluestone (copper sulphate) .'5 lbs. 



Lime (unslaked) .5 lbs. 



Water 50 gals. 



Dissolve the bluestone by suspending 

 it in a sack in water and dilute to 25 

 gallons. Slake the lime to an even paste 

 and add water to make 25 gallons. Mix 

 these dilute solutions by pouring to- 

 gether slowly into the spray tank or 

 barrel. Strain through a 20-mesh strain- 

 er made of brass wire while pouring into 



