The document discusses different types of losses that can occur due to pest infestations in crops in Bengal and India. Direct quantitative losses refer to parts of the crop like flowers, twigs, and shoots that are destroyed by pests chewing or sucking on the plant. Direct qualitative losses occur when pests lightly infest fruits before harvest through feeding or egg-laying. Indirect losses are economic in nature, such as decreased purchasing power for farmers and related industries due to reduced crop production. The actual loss takes into account the total monetary value of direct and indirect losses as well as costs of pest management and research. According to estimates, India loses around 10% of food grains annually and 18% of total production worth Rs.

1. YIELD LOSS Due To PEST In BENGAL & INDIA
CHAPTER : 2
The lossesdue to pest problems(infestation or infection) may be categorized in
many measures depending upon the significant of pests & their management .
 Direct Quantitative Loss :
The losses due to destroying of floral parts , twigs , shoots , etc . of crop
because of infestation through either chewing or piercing-sucking of
mouthparts ; are knownas direct quantitative losses , such as losses due to
locusts , hoppers , bollworms , borers , etc. .
 Direct Qualitative Loss :-
The losses due to light infestation of fruits by scale insects , puncturing of
normal fruit immediately before harvest owing to feeding or ovipositional
activity ; are known as direct qualitative losses , such as losses due to
Melon fruit fly(Bactrocera cucurbitae) , Mango fruit fly(B. dorsalis) , etc. .
N. B. – Infestation to fruit trees from blooming to harvesting results in
quantitative phase in earlier phase & qualitative in later phase .
 Indirect Loss :-
These are primarily of economic interest; eg. decreased purchasing power
of agriculturists and those depending upon agriculture owing to reduced
production. It would lead to decrease in related activities , reduced
productivity of agro-based industries , expenses incurred to import of agrl
produce and also forced acceptance of less desirable substitute products .
 Actual Loss :-
It includes the total value of losses , both direct & indirect , cost of pests
management measures alongwith the amount spent on researches for pest
management knowledge among agriculturists .

2. It was pointed out that , country loses 10 per cent(10%) of foodgrains
yearly due to severaldiverse pests problems , while preparing 4th.
Five year
Plan . By 1963 , the value of this loss was around Rs. 500crs.. According to
PESTICIDE ASSOCIATION Of INDIA the total loss due to several
diverse pests problems is approximately 18 per cent of our total production
or Rs. 5000crores annually of which losses due to various pests are as
follow(Mehta, P. R. in Pesticide Annual,1976, pp. 14-17) –
Weed = 33%
Disease = 26%
Insect-pest = 20%
Rodents = 6%
The adverse effects of these losses are not only economic . Our almost
social and political problems result from food shortage .