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Introduction
PBW=Pink Boll Worm, ABW=American Boll Worm, SBW=Spoted Boll Worm, SE=Spodoptera exigua, SL= Spodoptera Litura, CLCV= Cotton Leaf Curl Virus, Wf=White fly, SLM= Serpentine Leaf Miner The use of pesticides has been the dominant strategy
for pest control. The modern era of chemical pest control began with the
discovery of DDT followed by other synthetic pesticides such as chlorinated
hydrocarbons, Organophosphates, Carbamates, Synthetic Pyrethroids etc.
By and large pesticides have proved quite gainful in our agriculture and
public health programs. The consumption of pesticides in terms of Kg/ha
in India is the lowest (0.30) as compared to that of developed countries
i.e. Japan (10.80), Korea (6.60), Europe (1.90), and USA (1.50). The pattern
of pesticides usage in different crops is very much skewed. The cotton
and rice crops consume approximately 67% of the total pesticides used
in India. Avoidable losses due to insect pest attack and benefits of chemical control in terms of cost benefit ratio are depicted in the table below.
According to experts, one rupee spent on chemical control of pests can fetch 7 to 26 rupees by avoiding huge losses on crops like cotton, paddy, sugarcane, sunflower, mustard, vegetables and groundnut. Excessive and indiscriminate use of pesticides has resulted in many problems like higher and illegal residues, development of pesticide resistance, pest resurgence (pest outbreak), destruction of non-target organisms, environmental pollution and poisoning cases including accidental poisoning. India is the largest manufacturer of pesticides among the South Asian and South African countries Chemical pesticide industry in India at present comprises of the following three sections:
Presently insecticides still dominate the Indian market. However, in the past few years the share of herbicide and fungicide is steadily increasing and the over all consumption of chemical pesticide is declining. Resistance of insect pests to insecticides is one of the most serious problems in pest control. It has grown over the last five decades to such a serious dimension that now a days, it is a major challenge to pest control programs around the world. From five documented cases upto 1918, the number of insecticide resistant pests increased to 76 by 1957, 414 by 1978 and more than 504 by 1988. These include 283 species of agricultural importance, 198 species of medical and veterinary importance and 23 beneficial species. A number of species are resistant to insecticides belonging to all major groups.
In India, insecticide resistance
appeared first in insect pests of public health importance when mosquito
species developed resistance to DDT around 1952. Since then a number of
insect pests of medical and veterinary importance have developed resistance
to many insecticides. Resistance in agricultural important pests appeared
around 1963 in Singhara beetle to DDT. Later on insect pests like tobacco
caterpillar, diamond back moth, mustard aphid and green peach aphid also
became resistant to one or more insecticides. Appearance of resistance in
American Boll Worm is recent development, when large scale control failure
occurred in AP during 1987-88. In stored grain pests, the occurrence of
resistance to Lindane and malathion in rust red flour beetle was reported
around 1970. Subsequently resistance to malathion, Lindane or Phosphine
has been reported in other storage pests like rice weevil, lesser grain
borer and khapra beetle.
The goal of sustainable agriculture should be to maintain production at levels necessary to meet the increasing aspirations of an expanding world population without degrading the environment. Over the next two decades or so the following evolution is expected in pest control practices globally.
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