Abstract:
Aphids are sucking insects that remove plant sap and transmit
viruses. While few species of Aphids have broad host range and can cause
damage to variety of crops, others are restricted to only closely related plant
species . Plants respond to aphid attack by activating defence genes that
cause to the production of physical barriers and chemical toxic compounds
[direct resistance]. Specific volatile compounds released by attacked plants
can attract natural enemies of aphids. . A review conducted to evaluate the
effectivenesss of botanical extracts in controlling aphids on crop plants.
Aphids are tiny , soft bodied insects that sucks the juices of leaves. Low and
moderate infestations are less harmful but large infestations are quite
harmful. Preventive methods involve the application of insecticide and early
planting. Reliance on artificial chemicals to control pests has resulted in vast
destruction of unfocused organisms (parasitoids and predators) thereby
affecting biological diversity. The in vitro aphicidal activity of medicinal plant
essential oils, at concentrations of 1%, 2%, and 4% on the mortality of aphids.
Aphids are intentionally exposed to the botanical extracts and then number
of live and dead aphids are counted . The botanical extracts doesnot affect
the most of the predator , ladybirds beetles in the laboratory condition.
