10+ PESTS OF VEGETABLE CROPS. 



stems swollen and the leaves small. The symptom is one recognisable 

 to the trained eye, l>ut not easily disting-uished from the appearance of an 

 unthrifty stunted crop. An examination of the tubers on the main stems 

 reveals the pest at once, even if the beetles are not seen upon the leaves. 



The result of the attack is that the tubers are converted into a decay- 

 ing- mass unfit for food. A tuber on being cut exhales a peculiar sharply 

 aromatic odour, and the tissues round the tunnels darken when exposed 

 to air. If left alone the insect reduces the whole tuber almost to dust. 

 Tubers even lightly infested are iinfit for human food ; they may be 

 crushed and fed to cattle if not too much attacked. 



When a crop is once infested, nothing can be done to check the 

 pest; the infested potatoes must be destroyed to prevent the insect 

 breeding. Sweet potatoes should not be grown twice running on or near 

 infested land ; the pest must be starved out. Equally when a crop is 

 infested and spoilt, the whole crop must be dug ; small infested tubers 

 left in the ground afford a breeding place to the beetle and it is thus able 

 to attack the next crop. As a rule, a crop which grows deeply is not 

 attacked, and the beetles lay eggs only in tubers exposed on the surface^ 

 A deep rooting variety should be grown where the beetle is prevalent and 

 every precaution must be taken to ensure the total destruction of an 

 affected crop. 



Pests of Melons and allied Plants. 



Melons, cucumbers, pumpkins, and the like are moderately immune 

 from pests, no very important ones having yet been found. The Melon 

 Fruit Fly is discussed elsewhere (page 170) ; the best remedy against 

 this pest to melons in Baluchistan and the Punjab is to bury the young 

 fruits in the earth, as is now done, or to protect them by means of muslin 

 bags from the egg-laying flies. In India generally, pumpkins, melons 

 and all forms of cucurbitaceous fruits suffer from similar flies but not to 

 any serious extent. The maggots are found in the fruits here and there ; 

 the flies laying their eggs in the young green fruits. For all these, care 

 in the destruction of infested fruits is the rational check on their increase, 

 and a maggotty fruit should never be left to rot on the ground and 

 breed flies as is so often done. 



The Epilachna beetles are common pests on pumpkins, etc. ; they are 

 universal in India, feeding normally upon wild plants and multiplying 

 slowly on the crops. They are discussed separately (page 204). 



The Red Leaf Beetle^ is the most general pest of these plants 

 (fig. 233, page 200) ; it is found in all varieties, the beetle feeding among 



• 11, Aulacofhora fov0i0ollis, JCust. (Chrysomelidae.) 



