This document discusses several botanical insecticides including their characteristics, extraction methods, target pests, and modes of action. Limonene and linalool are extracted from citrus fruits and act as nerve toxins or stomach poisons. Rotenone is isolated from tropical legumes and inhibits electron transport chains in mitochondria. Sabadilla contains alkaloids that affect sodium channels. Ryania contains alkaloids that are stomach poisons or block the neuromuscular junction. While botanical insecticides were widely used in the past, commercialization faces barriers like scarce natural resources and regulatory approval. The future of botanical insecticides lies in overcoming these barriers and finding a coexistence with synthetic insecticides.

1. Botanical insecticides and their future
perspectives
By,
Bharati Singh

2. Characteristics of botanical insecticides
• Fast breakdown, Fast action
• Phyto toxicity, selectivity
• IPM friendly, cost and availability
Just because a pesticide is natural, does not
mean it is safe

3. Limonene and linalool
• Extracted from orange and other
citrus fruits
• Limonene , a terpene, and purified
by steam distillation
• Linalool, a terpene alcohol, found
in small quantities in citrus peel
d- limonene

4. • Limonene often applied with PBO (pyperonil
butoxide)
• Target pests: Fleas, aphids, mites, flies, paper wasp
• Mode of action:
• Act as nerve toxin and stomach poisons(limnonene)
• Affects ion transport and release of acetyl choline
esterase(linalool)

5. Rotenone
• Isolated from the roots of two tropical legumes
Lonchocarpus or Derris
• Extremely toxic to fish
Root of the Tuba
Rotenone structure
Deguelin structure
roots of the legume family (Fabaceae).

6. • Target pests: caterpillers, aphids, suckers and other
pests found in fruits and vegetables , certain beetles
• Mode of action- inhibits the electron transport chain in
the mitochondria
Rotenone’s safety is
somewhat
controversial
Electron Transport Chain

7. Sabadila
• Extracted from the seeds of the sabadilla
lilly (Schoenocaulon officinale)
• cevadine + veratridine = veratrine
2 : 1
S. Officinale
White hellebore

8. Mode of action
• Similar to that of the pyrethrins as it affects
the voltage dependent sodium channels of
nerve axons.
• Veratridine causes an increase in the duration
of the action potential

9. Ryania
• Obtained from the roots and stems of a South American
herbs (R. speciosa)
•
contain alkaloids with insecticidal activity, collectively
known as ryanoids

10. Ryanodine
mode of action
• Slow acting stomach poison
• Block neuromuscular junction
Neuromuscular junction
Most active ryanoid is ryanodine and 9,21-dehydroryanodine

12. Future Perspectives
• Botanical insecticides (BI) were major weapons (before 1940’s)
• Use of BI in California grew by almost 50% between 2006 and 2011
• Quite logical to expect coexistence of the two kinds of compounds i.e
synthetic and natural insecticides
• Barrier to commercialization
scarcity of natural resources
standarization and quality control
Regulatory approval

13. References
•
Dayan et al (2009), Bioorganic and medical chemistry 17, 4022- 4034, Natural
products in crop protection
•
Isman (1997) Phytoparasitica 25 (4): 339-344, Neem and other botanical
insecticides:Barriers to commercialization
•
Isman, Annu. Rev. Entomol.2006.51:45-66
•
Martina et al, Agriculturae conspictus scientificus .Vol. 78 (2013) No .2 (8593),Botanical insecticides in plant protection
•
Nikoletta et al, pesticides laboratory,Pesticides of botanical origin: A promising tool in
plant protection