Neem oil, also known as margosa oil, is a
vegetable oil pressed from the fruits and seeds of the neem (''
Azadirachta indica''), a tree which is indigenous to the
Indian subcontinent
The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...
and has been introduced to many other areas in the tropics. It is the most important of the commercially available products of neem, and is a potent
pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
used in organic farming.
Composition
Azadirachtin is the most well known and studied
triterpenoid in neem oil.
Nimbin is another triterpenoid which has been credited with some of neem oil's properties as an
antiseptic,
antifungal,
antipyretic and
antihistamine.
Uses
Ayurveda
Neem oil has a history of use in
Ayurvedic folk medicine
Traditional medicine (also known as indigenous medicine or folk medicine) refers to the knowledge, skills, and practices rooted in the cultural beliefs of various societies, especially Indigenous groups, used for maintaining health and treatin ...
.
Pesticide
Formulations that include neem oil have found wide usage as a
biopesticide for horticulturists and for
organic farming, as it repels a wide variety of insect pests including
mealy bugs,
beet armyworms,
aphids
Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...
,
cabbage worms,
thrips,
whiteflies,
mites,
fungus gnats, beetles,
moth
Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...
larvae, mushroom flies,
leaf miners
A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining insects are moths ( Lepidoptera), sawflies ( Symphyta, a paraphyletic group whi ...
,
caterpillars,
locusts,
nematodes and
Japanese beetles.
When sufficiently diluted and not concentrated directly into their area of habitat or on their food source, neem oil is not known to be harmful to mammals, birds, earthworms or some beneficial insects such as butterflies,
honeybees and
ladybugs. It can be used as a household
pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
for
ant
Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...
s,
bedbugs,
cockroach
Cockroaches (or roaches) are insects belonging to the Order (biology), order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known Pest (organism), pests.
Modern cockro ...
es,
houseflies,
sand flies,
snail
A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...
s,
termite
Termites are a group of detritivore, detritophagous Eusociality, eusocial cockroaches which consume a variety of Detritus, decaying plant material, generally in the form of wood, Plant litter, leaf litter, and Humus, soil humus. They are dist ...
s and
mosquito
Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...
es both as a repellent and as a larvicide.
[
Neem extracts act as an antifeedant and block the action of the insect molting hormone ecdysone. Azadirachtin is the most active of these growth regulators ( limonoids), occurring at 0.2–0.4% in the seeds of the neem tree.
]
Toxicity
Neem oil appears quite toxic by ingestion and can cause metabolic acidosis, seizures, kidney failure, encephalopathy and severe brain swelling in infants and young children.contact dermatitis
Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes ...
.
References
{{DEFAULTSORT:Neem Oil
Plant toxin insecticides
Vegetable oils