128 SDMI-; SOUTH INDIAN INSECTS, ETC. [CHAP. XII. 



Chapter XII. 

 I'll I CLASSIFICATION OF PESTS. 



•• I all nature swarms «iili life : one wond'rous m.i> 

 i it animals." 



Thom i 



In dealing with the various tacts concerning [nsect Pests it is 

 convenient to be able to arrange them in some definite method with 

 the object of facilitating reference to the information available 

 about any particular insect, its occurrence, life-history, relationships, 

 control. Such information may be classified in various ways, 

 the particular method adopted being adapted to the special 

 requirements in view. We may. for example, divide insect-pests 

 firstly into those that are noxious to man himself and his domestic 

 animals cither by direct attack or indirectly by conveyance of 

 disease or causing loss, and secondly into those which cause loss 

 by attacking his growing or harvested crops or other inanimate 

 possessions. 



Those insects included in the first category may again be 

 subdivided according to — 



(a) the animals attacked. 



(/>) the diseases carried, or 



(c) whether the insect is an adaptive or a casual carrier. 

 It is, however, chiefly with insects of the second category that 

 we are more immediately concerned and these may be divided 

 .11 cording to — 



(a) the object of damage, e.g., (i) Pests ot growing crops, (ii) 

 Pests of stored crops, (iii) Household pests, etc- ; 



(/>) the extent of damage. i.e., whether a major pest regularly 

 causing considerable loss of the crop or other object attacked, or 

 a minor pest of regular occurrence but causing relatively inconsi- 

 derable damage', whilst either of these may be sporadic or local or, 

 in other words, may occur occasionally but not regularly or ma) 

 only do damage in a limited area. 



rhe above headings ma j be still further subdivided, so that pests 

 of growing crops maj be considered under the head of cereals 

 pulses, tobacco, coffee, etc., and pests of cereals, for example, 

 may be considered separately as pests of paddy, cholam, cumbu 

 win', it, etc. 



Finally, all injurious insects, whether causing disease or 

 damaging crops or stored products, may be classified according to 



