Abstract:
The varied behavioral and physiological
responses which insects express against
various synthetic and natural toxins convey
how it influences pest behavior and reflects
the toxin's mode of action. Insects show
resistance through behavioral mechanisms
that reduce their subjection to insecticides and
through the evolution of physiological
mechanisms allowing them to deal with high
insecticide levels in or on the body [1].
The conditions of relatively high humidity
and temperature in tropical and subtropical
countries are ideal for cultivating several
grain types as well as for the large-scale
propagation of all kinds of insects that can
cause unsatisfied storage infrastructure for the
grain stocks [2].
The harmful effects on the environment and
health, greater selection pressure and the
increment in the genetically resistant strains
to the insecticidal active ingredients, and
undesirable failures in supply and control
management systems have been identified as
the major limitations of the endless usage of
synthetic insecticides. To get rid of these
issues, discovering efficient methods for pest
control is necessary. Therefore, it is essential
to find out new substances that will fulfill the
requirements of toxicological safety, low
environmental impact, and agronomic
efficiency for the beneficial control of insect
pests of stored grains [3].
Recent investigations have proven that the
efficiency of plant extracts as promising
stored-grain protectants and several bioactive
compounds which can be used as alternative
insect control agents have been recovered.
Phytochemical pesticides are advantageous
for providing novel modes of action against
insects that can reduce the risk of cross resistance as well as offering new leads for
designing target-specific molecules [4-6].
According to the literature of Annona
muricata L., although the seed is reported to
have strong insecticidal effects, the leaves
have not yet been recommended as the
chemical and nutritional contents in recent
times.
Therefore, the current study has been
conducted to separate the bioactive
compounds according to the polarity and
evaluate the bioactivity of methanol extract
and fractions obtained from A. muricata
leaves against Sitophilus zeamais
Motschulsky which is the main pest species of
stored cereals in tropical conditions with the
aim of discovering new eco-friendly natural
insecticides.
