« HAP. XL] THE C)\i koi. OF [NSEC1 PESTS OF (Roc-. 



123 



and the furnace is much larger and is placed directly over the top 

 of the nest to be treated. Provision is also made I'm the application 

 of the sulphur mixture through a door, closed with .1 screw-bolt, in 

 the metal pipe joining the fan and the furnace. The possibility 

 of introduction of the poison without opening the furnace and the 

 use of a fan instead of a pump are decided advantages bul tl 

 are rather outweighed by the excessive weight of the apparatus and 

 particularly of the furnace. If the rotary fan could he fitted to a 

 light steel pipe, provided with a sliding door for insertion of the 

 sulphur, and this latter connected to a smaller furnace whose fu 

 were led out by a flexible metal piping, a more useful and portable 

 machine would he produced. 



I I I 



Lnt 1 •■ :. ..:. ' 



Fungal and Bacterial Diseases. The control of insect-pests art i- 



licialh by means of fungal or bacterial diseases which attack them 

 and reduce their numbers under natural conditions is at first sight 

 a very promising ami easy method. The idea of simply scattering 

 amongst his crops a small quantity of some culture of such diseases 



iving this to do all the work of protecting his fields from 

 damage is one that appeals intensely to tin- common run of cultivator 

 who expects to obtain great results without any trouble or exertion on 

 his own part. The success which has attended the use ol fungal 

 enemies of some scale-insects in the West Indies is held 11 

 example of what may he done in India where the conditions are 

 entirely different. Green Scale-hug (Lecanium viridej, for example, 

 in Southern India is heavily attacked by several fungi which kill 

 oft perhaps ninety percent, of the insects during the intensely wet 

 weather experienced in the Coffee Districts. These fungi are well 

 distributed, almost everj hush attacked by the stales showing 

 them in large numbers. And yet the rate ot increase of th - 



LSI that it is not killed out hut merely checked temporarily 



