Question
Write the modes by which insects affect the crop yield.
✓
Answer
Some common insect pests of stored grain and their mode of infection are:
- Gram dhora or Pulse beetle (Callosobruchus maculatus) Its grubs, damage the stored gram.
- Rice weevil: (Sitophilus oryza) Both grub and beetle (adult) damage rice.
- Khapra or Wheat weevil: (Trogoderma granarium) Infests stored wheat.
- Grain and flour moth: (Sitotroga cerealella) Its caterpillars bore into grains of rice, wheat, barley, maize and jowa.
- Rust red flour beetle: (Tribolium castaneum) Both larvae and adult damage flour and flour products.
- Rice moth: (Corcyra cephalonica) Larvae damage rice and maize.
- Lesser grain borer: (Rhizopertha dominica) Both grub and adult (beetle) damage the grains, reducing them to perforated shells.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Write down four main characters of gymno-sperms.
List five characteristics by which compounds can be distinguished from mixtures.
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement–time graph is shown in Plot a velocity–time graph for the same.
If the back of your hand is moistened with alcohol, you will find that it rapidly becomes dry. Why is it that while it is drying, your hand feels cool?
Universal law of gravitation states that every object exerts a gravitational force of attraction on every other object. If this is true, why don’t we notice such forces? Why don’t the two objects in a room move towards each other due to this force?
Define connective tissue. Write down functions of connective tissue.
State the main points of difference between homogeneous and heterogeneous mixtures.
What mass of nitrogen $N_2$, will contain the same number of molecules as $1.8g$ of water, $H_2O$? (Atomic masses: $N = 14u; H = 1u; O = 16u$)
→Why are mitochondria called powerhouse of the cell? Give three similarities and one difference between mitochondria and plastid.
On a level road, a scooterist applies brakes to slow down from a speed of $10m/s$ to $5m/s$. If the mass of the scooterist and the scooter be $150kg$, calculate the work done by the brakes. (Neglect air resistance and friction)
→