Southern cowpea weevil

Classification

Primary pest; Grain feeder
Order: Coleoptera
Family: Chrysomelidae
Acronym: CCH

Description

• Adults are small (3 to 4 mm long), globular body with long legs and long antennae.
• Elytra are patterned and the last abdominal terga is exposed.
• Larvae are white and grub-like with reduced legs.

Similar species

• Bean weevil (Acanthoscelides obtectus)
• Pea weevil (Bruchus pisorum)
• Other species of Callosobruchus.

Commodities affected

• Chickpeas, lentils, garden peas, mung beans

Signs of infestation

• Emergence holes from seed are obvious and characteristic.

Damage

• Damage is distinctive. When adults emerge from a seed, they leave a neat circular exit hole.
• Heavy infestation can cause commodity to heat, resulting in a loss of quality and mould growth.

How to control

• Control grain insect pests

Geographic range

• Is abundant in the tropics
• Has been recorded from Saskatchewan, Manitoba, Ontario in Canada

Where found

• Is occasionally found in beans imported to Canada
• Is a pest of stored beans, peas and wild legumes
• Attacks field beans and peas in the field
• Can be a storage pest in granaries where it will breed continuously on dried pulses
• Requires high temperature and moderate relative humidity to reproduce well, so does not do well in Canada

Life history

• Adults are very active and will run and fly readily.
• Females lay eggs by attaching to the outside of the seedcoat.
• Larvae feed and develop within the seed.
• Prior to pupation, the larvae chews an exit hole for the adult to emerge from.

Video

• Video of southern cowpea weevil