**Abstract**

Aphids are important herbivores and important pest of many field and forest crops. They have specialized long and flexible stylets which are adapted to feeding on phloem sap. To establish successful feeding on host plant, they need to counter a range of both physical and chemical defenses. The defenses employed by plants can have direct effect on the aphid species through difficulty in establishing successful feeding due to the presence of trichomes, thick cell wall, etc. or effect on their biology with lethal consequences in extreme cases (direct defenses). In contrast to this, plants can attract natural enemies of aphids through the release of volatile compounds (the so-called "cry or call for help") (indirect defense). The information on different defense strategies employed by plants can be utilized to enhance the level of resistance (R) to develop sustainable pest management strategies.

**Keywords:** Aphidoidea, insect-plant interactions, phloem feeding, plant defense, sieve elements
