When does ipm use synthetic chemical pesticides?

The IPM or Integrated Pest Management only use synthetic chemical pesticides as a last resort. The IPM is a way to deal with the pests. It aims to decrease the population of the pests below normal level to avoid mass destruction of crops by pests and other insects.  

Synthetic chemical pesticides are ruthless and efficient in doing their jobs but they also leave some damage behind. Most pesticides that use synthetic chemicals are harmful to the crops as well as for our bodies. Using them in large quantities is not recommended.  

Vectors-These are diseases transmission which involves the piercing of the skin-vectors penetration  e.g by mosquito. ticks.

Air borne which involves entry through the nasal passages, mouth, eyes to reach the body  the respiratory tracts and the blood.

Blood borne diseases are  transmitted from e.g piercing of the skin by  contaminated objects needles, broken glass. If there is an opening in the skin these transmission is also possible.

Sexual can be transmitted through open sores at the genitals.or  use of  contaminated needle by infected subject. Sores in the mouth during kissing may be another route

food borne or water borne needs to enter through natural opening of the mouth to reach the body fluids and the blood through the GIT.

Contact diseases does not necessarily need a direct opening for transmission . rather there should be a direct contact between the infected individual and the other. Sometimes a direct contact between the two is not need. e.g common cold, chicken pox , influenza , etc.  

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