Write the modes by which insects affect the crop yield.

Explanation

Some common insect pests of stored grain and their mode of infection are
(i) Gram dhora or Pulse beetle (callosobruchus maculatus) its grubs, damage the stored gram
(ii) Rice weevil (Siophilus oryza) Both grub and beetle (adult) damage rice
(iii) Khapra or Wheat weevil (Tragoderma granarium) Infests stored wheat
(iv) Grain and flour moth (Sitroga cerealella) Its caterpillars bore into grains of rice. wheat barley maize and jowa
(v) Rust red flour beetle (Tribolium castaneum) Both larvae and adult damage flour and flour products
(vi) Rice moth (Corcyra cephalonica) Larvae damage rice and maize
(vii) Lesser grain borer (Rhizopertha dominica) Both grub and adult (beetle) damage the grains reducing them to perforated shells