116 



These plants are not easy to protect from the attacks 

 of the insects just mentioned, because of their susceptibility 

 to injury by insecticides. Dilute whale-oil soap or tobacco 

 solutions may be used as a spray, while wood-ashes, soot and 

 very light dressings of lime may be found useful applied in 

 the form of dust. 



The plants in this group are also frequently severely 

 attacked by nematodes or eel worms. These are minute, or 

 almost microscopic, white worms which live in the soil and 

 penetrate the tissues of the roots of plants of many kinds, 

 producing swellings and deformities. 



The effects of nematode attacks are most noticeable in 

 gardens, but it is likely also that these pests cause very con- 

 siderable losses on estates. 



The remedies consist of clean cultivation, rotation of 

 crops, and the free use of lime in the interval between crops. 

 Once the worms have penetrated into the root tissues, 

 they are protected from insecticides to a very large extent. 

 The use of solutions of whale-oil soap, applied to the soil 

 about the roots, will often check the increase of these pests 

 sufficiently to allow a useful plant a longer life than if they 

 are allowed to go unchecked. 



Carbon bisulphide and a solution of potassium cyanide 

 are also useful for this purpose. 



Tomatoes and peppers are attacked by large green 

 caterpillars, similar in size and general appearance to the 

 potato and tobacco worms. These plants are also often 

 infested with white fly, scale insects and mealy-bug. The 

 egg plant, or garden egg is related to the tomato and 

 pepper, and is often infested by the same pests. A very 

 delicate hemipterous insect which is fairly common 011 the 

 egg plant is the lace bug. The wings of this insect are 

 membranous, very thin in texture, with numerous strong 

 nerves or veins, presenting the appearance of a delicate 

 pattern in lace. 



Onions are attacked by thrips, which destroy the 

 epidermis of the leaves and seriously interfere with the 

 growth of the plants. Cutworms also prey upon onions, 

 severing the young plants near the surface of the soil, or 

 later climbing up to feed on the leaves at night and 

 returning to hide through the day in the soil at the base 

 of the plant, where they may often be found and des- 

 troyed. Caterpillars are sometimes found hiding inside 

 the hollow leaf of the onion, where they feed until the 



