Mango nut weevil/stone weevil, Sternochetus mangiferae (Curculionidae:Coleoptera)

• Serious and regular pest affects export potential of mango (quarantine pest).
• Attacks only mango (Totapuri highly susceptible)
• Adults hibernate on the tree trunk during off season

Appearance:

• Adult is dark brownish stout weevil
• Grub are light yellow with dark head and apodous

Biology:

• Females scoop out the surface of developing fruits and lay eggs individually
• IP- 7 days; LP- 35-40 days; PP- 7 days
  Pupation in the stone

Nature of damage:

• Grubs after hatching tunnel in zig-zag manner through pulp, endocarp and the seed coat and feed on cotyledons.
• As the fruit develop damage heals up
• Adults also feed on the cotyledon
•  Adults make hole and come out of the fruit

Damage symptoms:

• No external symptom is visible
• The size and weight of the fruit reduced
• Early maturation of fruits
• Fruits with emerged holes will rot
• Affects germination of seed