Environmental Engineering Reference
In-Depth Information
O
M. azedarach
, otherwise known as chinaberry
or Persian lilac tree, is a deciduous tree that origi-
nates from northwestern India, and it has been
recognized for its insecticidal properties, which
are still to be entirely analyzed. This tree grows in
the tropical and subtropical parts of Asia, but
nowadays it is also cultivated in other warm
places of the world because of its considerable
climatic tolerance. The leaves of
M. azedarach
are used for their insecticidal activity, whereas
the fruit extracts of
M. azedarach
produce a vari-
ety of effects in insects, such as growth retarda-
tion, reduced fecundity, molting disorders, and
behavior changes (Ascher et al.
1995
).
The antifeedant and insect growth-regulating
effects of
M. azedarach
extracts are known for
many insects (Connolly
1983
; Saxena et al.
1984
;
Champagne et al.
1992
; Schmidt et al.
1998
; Juan
et al.
2000
; Carpinella et al.
2003
; Senthil-Nathan
2006
; Senthil-Nathan and Sehoon
2006
), the latter
effect being the most essential physiological effect
of
M. azedarach
on insects (Ascher et al.
1995
).
As previously mentioned, the Meliaceae plant
family has been known as a potential source for
insecticide properties. Also, several extracts from
neem and other plant seeds and leaves have excel-
lent insecticidal properties against vectors and are
at the same time very eco-friendly (Schmutterer
1990
; Senthil-Nathan et al.
2005a
,
b
,
c
). The effi -
caciousness of these neem products on mosqui-
toes was also demonstrated (Chavan
1984
; Zebitz
1984
,
1986
; Schmutterer
1990
; Su and Mulla
1999
; Senthil-Nathan et al.
2005d
).
Without a doubt, plant-derived toxicants are a
valuable source of potential insecticides. Plants
and other natural insecticides may play a vital
role in mosquito control programs as well as in
other major insect control programs (Mordue
(Luntz) and Blackwell
1993
).
O
C-OCH
3
o
OH
o
OH
o
O
7
o
O
CH
3
C
-
O
OH
C
o
H
CH
3
O
O
Fig. 5
Structure of azadirachtin
borer, rice gall midge, rice leaffolder, and grass-
hopper (Dhaliwal et al.
1996
; Nanda et al.
1996
;
Senthil-Nathan et al.
2009
).
7.2
Melia azedarach
The promotion of botanicals as eco-friendly pes-
ticides, microbial sprays, and insect growth regu-
lators has been a major concern amid the presence
of other control measures like benefi cial insects,
all of which demand an integration of supervised
insect pest control (Ascher et al.
1995
). Plant-
based insecticides are developed naturally from
plant chemicals extracted for use against serious
insect pests. As a result of concerns about the
ecological continuity of synthetic pesticides and
their potential toxicity to humans, nontarget ben-
efi cial insects, and some domestic animals, there
is a regenerated interest in natural products to
control insect pests. From this conclusion, the
development of biopesticides seems to be a logi-
cal choice for further investigation. Meliaceae
and Rutaceae species have received much atten-
tion due to the fact that they are a rich source of
triterpenes known as limonoids (Connolly
1983
).
The Meliaceae plant family is known to hold
an assortment of compounds with insecticidal,
antifeedant, growth-regulating, insect-deforming,
and growth-modifying properties (Champagne
et al.
1989
; Schmutterer
1990
; Mordue (Luntz)
and Blackwell
1993
; Senthil-Nathan and
Kalaivani
2005
,
2006
; Senthil-Nathan
2006
;
Senthil-Nathan et al.
2004
,
2005a
,
b
,
c
).
8
Biochemical Pesticides
8.1
Pheromones
Insects produce chemicals called pheromones to
stimulate a certain behavioral reaction from other
individuals. These pheromones have numerous
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