40 SCALE PESTS OF COFFEE 



whole branch may be deserted for another. Fallen 

 leaves containing bugs are carried long distances by the 

 wind and they may carry infection very far. The adults 

 have been found to survive a burial of twenty days. This 

 is amply long enough to allow their being swept away by 

 the wind, either free or on leaves, to find a new plant and 

 to become fixed upon it. 



Where shade trees have become infected, either 

 directly by green bugs crawling on to them or by the 

 action of ants, the danger of spread of the pest by the wind 

 becomes much greaterx 



The agency of human beings and animals is also im- 

 portant. Coolies moving about among infested plants 

 may carry large numbers, more especially of the young 

 bugs which have not yet fixed themselves, to uninfected ., 

 areas either on their clothing or on their ^bodies. Bir4s'^v'!^!^>. 

 and animals may also spread the pest. 



Host Plants in Mysore. 



There are only a few plants on which the new species 

 has been so far found, viz., Albizzia spp. Wrightia tinc- 

 toria, x\egle marmelos, Artocarpus integrifolia, Mangifera 

 indica, Psidum guyava, Citrus spp., Ficus spp. and Eugenia 

 Jambolana. 



The effect on host plants. — -The method of feeding of 

 the green bug has already been described. The attachment 

 of the bug along veins is apparently for the purpose of 

 allowing it to draw on the elaborated food material that 

 "passes downwards to the branches and trunk. Where 

 there are several hundreds of bugs drawing away what 

 ought to go to the formation of new wood, the plant 

 naturally suffers. Growth is impeded. Fresh wood is not 

 formed. Even more serious is the collapse of the con- 

 ducting vessels which takes place on very badly infested 

 plants. On plants in pots, the green bark has been found 

 to shrink so suddenly that the bugs were unable to with- 

 draw the proboscis and move elsewhere. 



Plants so badly affected invariably die. This, bow- 

 ever, has never been observed in the estates. The insects 

 affect the crops more directly. When blossoms are 

 attacked, and subsequently the berries, the latter are 

 reduced in size and often thrown out of normal shape. 



