2. Rice weevil
Common Name - Ghun, killa, Ghanera,
Sund wali sursuri.
Systematic Position:-
Scientific Name - Sitophilus oryzae
Order - Coleoptera
Family - Curculionidae
Status –
most destructive pest of stored grains.
3. Rice weevil
Hosts :
• Rice
•Wheat
• Maize
•Jowar
• Barley
• Other food grains and processed food.
Distribution :
The pest is world wide and found particularly
throughout India.
5. Biology :-
Eggs –
• Laid singly
• Translucent white in colour.
• Arround 0.7mm long and 0.3mm broad.
• It makes a cavity in the grain, lay eggs and plugs the hole with secreted material
from ovipositor.
Grubs –
• Tiny legless
• White body with yellowish brown head
• Plumpy, fleshy creature
• Full grown grub is 5mm in length.
Rice weevil
6. Pupa –
• Pupate inside the grain.
• At first, the pupa is dirty white, but later become dark brown.
Adult –
• Small reddish brown beetle with a long snout.
• 3mm in length having cylindrical body.
• Meta thoracic wings are well developed.
• Elytra bears four light reddish or yellowish spots.
Rice weevil
7. Life Cycle :-
• Female starts laying eggs after 4-5 days
of emergence.
• Breeds from april to oct.
• Hibernates as adult in winter inside
cracks and crevices.
• Fecundity – 400 eggs/female
• Adult lives for about 4-5 months.
• Generally 5 generations in a year.
Rice weevil
10. Damage :-
Nature –
• Both grub and adult cause damage.
• Break and hollow the grain.
• Grubs are more destreuctive than adults.
• Attacks in field too.
Rice weevil
11. Extent of damage –
• Affected grains become unfit for human
consumption.
• Damage is both quantitative and
qualitative.
• In north India, the greatest damage is
caused from july to nov.
• In India, the loss to stored grains by this
pest alone is valued at many crores of
rupees every year.
• In case of severe infestation only
fragments of pericarp with frass are left
behind.
Rice weevil
