Negative impact of chemical pesticide

a. Development of resistance in insects: Pests have an innate capacity to endure pesticides and escape lethality. The moment of a certain insect should have this capacity which is called pesticide resistant. Continual exposure and intensity of pesticides induce the target pest to develop a resistance generation.

b. Outbreak of pest: Mass destruction of the natural enemies due to pesticide influence also creates a congenial environment for major and minor pests.

c. Hazard of pesticide residue: Depending on the inherent nature of the chemical build-up of a pesticide it depletes its toxicity in time. Before they given up their toxicity due to environmental weathering factors, this chemical leftover persisted becoming a potential

d. Environment Pollution: Only one-half of the treated pesticide deposits itself on the treated surface the rest is disseminated to uncharged areas. This makes the environment polluted. They remain in water, soil, air, and mammal adipose tissues for a long time and may cause long-lasting time.

e. Phytotoxicity: Depending on the nature of pesticides plants may be harmed because of chemical interactions among plants and pesticides. Burning spot-on leaves, distorted leaves, restricted growth, and other undesirable symptoms are seen in plants.

f. Adverse effect on non-target organisms: Use of pesticides against target pests affects insect parasitoids and predators, honeybees, other pollinators, and wildlife also, which causes the loss of biodiversity. Repeated use of pesticides on crops has disruptive effects on beneficial insects like pollinators, bio-control agents, soil wild and aquatic life. Many invertebrates take up pesticides from the soil into their bodies and may concentrate pesticides several times greater in their tissues than those in the surrounding soil. Soil microorganisms that cause the breakdown of cellulose, nitrification, turn-over of organic matter, and other biological materials may also be adversely influenced by pesticides. Indiscriminate use of insecticides on field crops has resulted in widespread mortality of honeybees and wild bees which are essential for pollination.

g. Resurgence of pest: Resurgence refers to an abnormal increase in pest population following insecticide application. The use of broad-spectrum and persistent insecticides kills the natural enemies resulting in a resurgence of insect pests. Sometimes, pesticides kill the key pests and under such conditions, secondary pests become the primary pests. Resurgence may also develop due to an increase in feeding and reproductive rates of insects due to the application of sub-lethal doses of pesticides. Resurgence is a dosage-dependent phenomenon and hence emphasis should be placed on the correct dose of effective and recommended pesticide.