Scientific Name : Callosobruchus chinensis (Linnaeus, 1758) 

Common Names: Adzuki bean weevil, Southern Cowpea Weevil

Synonyms

Bruchus chinensis Linnaeus 1888

Taxonomic Position

Class: Insecta

Order: Coleoptera

Family: Bruchidae

Genus: Callosobruchus

Species: Callosobruchus chinensis

Origin and Distribution

C. chinensis originated in tropical Asia where it is still the dominant species and are distributed throughout the tropics and sub-tropics.

Host Range

Cajanus cajan (pigeon pea)  , Cicer arietinum (chickpea), Glycine max (soyabean), Lablab purpureus (hyacinth bean), Lathyrus sativus (grasspea), Lens culinaris subsp. culinaris (lentil), Mucuna pruriens (velvet bean), Oryza sativa (rice)      , Phaseolus (beans), Phaseolus lunatus (lima bean), Phaseolus vulgaris (common bean), Pisum sativum (pea), Psophocarpus tetragonolobus (winged bean), Triticum aestivum (wheat), Vicia (vetch), Vicia faba (faba bean), Vigna aconitifolia (moth beans), Vigna angularis (adzuki bean), Vigna mungo (black gram), Vigna radiata (mung bean), Vigna unguiculata (cowpea).

Pest Destructive Stage

Primary pest

Eggs –laid or stuck individually onto seed or pod

Larvae – immobile, concealed within seed

Adults – do not feed on commodity, fly readily

Damage symptoms

Damage is distinctive. As adult emerge from seeds they leave behind neat circular holes in the seed, behind which is a large cavity left by the larvae.

Identification features

Morphological Features: Eyes strongly bulging, antennae strongly dimorphic in sexes, serrate in female, Pectinate in male, elytra with a pair of Tubercles at the Bases of 3^rd and 4^th striae in the male; each paramere with an apical papilla, exophallic valve acuminate.

Species Key

• Pygidium in both sexes convex, male with vague patches at middle and at apex, female with more intense patches sometimes connected to form paired crescents.
• Elytral striae three and four each with prominent sub basal denticles on slight gibbosity .Antennae dark brown.
• Elytra covered with transverse rows of setae consisting of an anterior broad golden band and two white bands in the middle, leaving in each two large black spots uncovered with setae, 3^rd striae straight; legs reddish.

Detection methods

Samples can be examined with naked eye or under magnifying glass or stereoscopic binocular microscope and by using soft X-ray and seed transparency method hidden infestation can be detected.