TOBACCO PESTS. 



157 



The life history is similar to that of other moths, the eg-g-s being 



laid on the plant, the caterpillars 

 feeding" on the leaves, the pupa 

 lying in the earth without a 

 cocoon, the moth lying hidden by 

 day and emerging at dusk. In the 

 hot weather or rains the whole 

 life history is passed in about a 

 month ; the insect liibernates as a 

 pupa or larva, emerging in March. 

 If tobacco is not available, the 

 caterpillar attacks a variety of crops 

 and is a pest in gardens (see page 

 181). 

 Another species attacking tobacco is a green caterpillar, with a 

 similar life history ; it is a common insect in the plains, the moth ^ being 

 closely similar to that of the Gram Caterpillar, both being of the same 

 genus. When the tobacco is young, an application of lead arseniate 

 does good, poisoning all caterpillars that feed on it. This application 

 cannot be made to plants that have large leaves and are within a short 

 time of ripening, as the arsenic might remain on the leaves. A fort- 

 night before cutting is the very latest date on which arsenic can be 

 safely applied. In such a case nothing but hand-picking is possible, 

 and a careful watch must be kept for such caterpillars in the last growth 

 of the tobacco plants. 



Fig. 177. 

 Moth of Tohacco Leaf Caterpillar, 



Minor Tobacco Pests. 



Surface grasshoppers are commonly found attacking newly set out 

 plants of tobacco, eating the leaves and destroying the young plants. 

 Even if the plants are not killed, the crop becomes very uneven. To 

 check this the grasshoppers should be removed before transplanting ; 

 where possible the transplainted seedlings shovild be dipped in the lead 

 arseniate mixture used to poison the leaves ; the young plants grow quite 

 well and regularly (page 220). 



Crickets are also found attacking young tobacco, and where this is a 

 valuable crop, the ravages of the large crickets may be important 

 (page 224). 



The seed capsules are eaten by several caterpillars, including the 



' 158, 1 Chloridea assulfa, Gueii. (Noctuidffl.) 



