Bio-pesticides are a type of pesticide derived from natural materials as animals, plants, bacteria, and certain minerals.

Bio-pesticides or biological pesticides based on pathogenic microorganisms are specific to a target pest, offer an ecologically sound and effective solution to pest problems.

The use of botanicals is now emerging as one of the most viable means of protecting crop produce and the environment from pollution from chemical pesticides. The shift from synthetic pesticides to non-synthetic ones is because of the widespread awareness of the side effects of these synthetic pesticides not only on plants and soil but also on other living organisms. Excessive use of synthetic insecticides has resulted in a series of problems like the development of insect resistance to insecticides, harm to other natural enemies of insects, toxic effects on plants and soil etc.


The neem (Azadirachta indica) belongs to the Meliaceae family. It is an evergreen tree, usually growing up to a height of 15–20m. It is native to North-East India, and nowadays, it is mainly present in all Indian subcontinent and in subtropical regions of America, Asia and Africa. The neem tree grows naturally throughout the dry regions. Its capacity to fight the desertification makes the neem as a life-giving tree, improving the cultivation in sub-arid to sub-humid conditions, especially for the dry coastal districts. The other treasure of neem is inside the fruits, produced in great quantity. The fruit is a small drupe, ellipsoid in shape, about 2 cm long, yellow-green. Neem is one of the most sacred trees in India.The spiritual meaning of neem is in its medicinal properties.


Neem seed extracts contain azadirachtin, which in turn works by inhibiting the development of immature insects. Neem oil enters the system of the pests and obstructs their proper working. Insects do not eat, mate and lay eggs resulting in the breaking of their life cycle. Another interesting function of neem oil pesticides is that they do not harm the beneficial insects. 
The neem oil insecticides only target the chewing and sucking insects. Natural properties of neem do not have any toxic reactions, so they are helpful in plant protection and management. All the parts of neem like seed, flowers, bark, and leaf can be used to produce high quality product. It is interesting to note that neem doesn’t kill insects, but alters their life process. Instead of killing the pests, it affects the life cycle of the pests. Pests generally do not develop a resistance to neem-based pesticides. Neem pesticides are generally water soluble and help in the growth of the plants. It acts as pest repellent and pest reproduction controller.

Mode and specificity of action of Neem

Oviposition deterrence

Application of neem formulations have prevented the females from depositing eggs. The effect of neem-based pesticides on the reproductive potential of aphids has been attributed to blocking the neuro-secretory cells by the active ingredient, azadirachtin, which disrupts adult maturation and egg production.


When crops were treated to neem products, anti-peristaltic wave were observed in the alimentary canal which produced an action similar to a vomiting sensation in the insect during feeding. This was attributed to the presence of azadirachtin, salanin and melandriol. Because of this sensation, the insect does not feed on the neem-treated surface. Its ability to swallow was also blocked.

Growth regulator

The products work on juvenile hormones. The insect larva feeds and as it grows, it sheds its old skin. This process is governed by an enzyme, ecdysone. When the neem components gains access to the body of the larva, the activity of ecdysone is suppressed and the larva fails to moult. Based on azadirachtin concentration, the larva will die after the pupal stage or the adult will be sterile.



Lokanadhan, Subbalakshmi, P. Muthukrishnan, and S. Jeyaraman. “Neem products and their agricultural applications.” Journal of Biopesticides 5 (2012): 72.


Agbo, B. E., A. I. Nta, and M. O. Ajaba. “Bio-pesticidal properties of Neem (Azadirachta indica).” Adv. Trends Agric. Sci 1 (2019): 17-26.


Benelli, Giovanni & Canale, Angelo & Toniolo, Chiara & Higuchi, Akon & Murugan, Kadarkarai & Pavela, Roman & Nicoletti, Marcello. (2016). Neem ( Azadirachta indica ): towards the ideal insecticide?. Natural Product Research. 31. 1-18.