• Immature parasitoids, especially if protected within the egg of their host or in their
own cocoon, may tolerate pesticides better than adults, but immature parasitoids
will usually die if their host is killed.
• To improve the abundance and diversity of beneficial insects especially
parasitoids and predators it is necessary to consider native vegetation on the
farm as a part of a pest management strategy.
• Sometimes multiple parasitoids may emerge from one pest.
11.9.3 Advantages of Predators in Biological Pest Management
• Bigger in size, prey many hosts, can reduce the pest population potentially.
• Not much affected by external environmental conditions and pesticides compared
to parasitoids.
11.9.4 Disadvantages of Predators in Biological Pest Management
• Non-host specificity.
• Mass multiplication is difficult.
• Cannibalism is common in many predators.
11.10 Biochemical Pesticides
Phytochemicals or herbal pesticides are chemicals derived from plant origin. Each
phytochemical possesses specific structure, performs various functions such as
protection, growth acceleration and reproduction in plants (Huang et al. 2014).
Phytochemicals are found in various parts of the plants like fruits, vegetables, grains,
pulses, nuts, seeds, bark, etc. Since it has several bioactive compounds that contain
antiparasitic, bactericidal, fungicidal, viricidal and insecticidal properties, it can be
considered as a potential alternative for inorganic pesticides. These are secondary
metabolites produced by plants by nature such as (1) terpenes contain phytovolatiles, glycosides, (2) sterols contain phenolic compounds such as phenolic
acids, lignin, tannins and alkaloids. Secondary metabolites play an important role
in the plant defence system against insects. It acts as a toxicant, insect growth
regulator, repellents and antifeedant (Mossa 2016). Phytochemicals from the plants
can be extracted using solvent extraction, microwave-assisted extraction, ultrasonicassisted extraction based on the presence of a group of phytochemicals present in it
(Altemimi et al. 2017). At present only a few phytochemicals are used as
biopesticides and most of them are neem-based (Table 11.8). These are mainly 3%
neem oil or 5% neem seed kernel extract concentrates which can be applied at 25 kg/
ha against major field pests.
11 Biopesticides for Pest Management
257
own cocoon, may tolerate pesticides better than adults, but immature parasitoids
will usually die if their host is killed.
• To improve the abundance and diversity of beneficial insects especially
parasitoids and predators it is necessary to consider native vegetation on the
farm as a part of a pest management strategy.
• Sometimes multiple parasitoids may emerge from one pest.
11.9.3 Advantages of Predators in Biological Pest Management
• Bigger in size, prey many hosts, can reduce the pest population potentially.
• Not much affected by external environmental conditions and pesticides compared
to parasitoids.
11.9.4 Disadvantages of Predators in Biological Pest Management
• Non-host specificity.
• Mass multiplication is difficult.
• Cannibalism is common in many predators.
11.10 Biochemical Pesticides
Phytochemicals or herbal pesticides are chemicals derived from plant origin. Each
phytochemical possesses specific structure, performs various functions such as
protection, growth acceleration and reproduction in plants (Huang et al. 2014).
Phytochemicals are found in various parts of the plants like fruits, vegetables, grains,
pulses, nuts, seeds, bark, etc. Since it has several bioactive compounds that contain
antiparasitic, bactericidal, fungicidal, viricidal and insecticidal properties, it can be
considered as a potential alternative for inorganic pesticides. These are secondary
metabolites produced by plants by nature such as (1) terpenes contain phytovolatiles, glycosides, (2) sterols contain phenolic compounds such as phenolic
acids, lignin, tannins and alkaloids. Secondary metabolites play an important role
in the plant defence system against insects. It acts as a toxicant, insect growth
regulator, repellents and antifeedant (Mossa 2016). Phytochemicals from the plants
can be extracted using solvent extraction, microwave-assisted extraction, ultrasonicassisted extraction based on the presence of a group of phytochemicals present in it
(Altemimi et al. 2017). At present only a few phytochemicals are used as
biopesticides and most of them are neem-based (Table 11.8). These are mainly 3%
neem oil or 5% neem seed kernel extract concentrates which can be applied at 25 kg/
ha against major field pests.
11 Biopesticides for Pest Management
257