TEST OF PRACTICAL KNOWLEDGE QUESTION (a) Identify specimens K and L. Specimen K; Specimen L; %% (b) List three crops commonly attacked by each of specimens ...

Answer Details

(a) Identification

• Specimen K: Rhinoceros beetle (adult beetle, order Coleoptera), recognised by the hard black exoskeleton, the prominent horn on the head and the hardened forewings (elytra) covering membranous hind wings.
• Specimen L: Rat (a rodent), recognised by the covering of fur, the long scaly tail, the chisel-like continuously growing incisors and the four clawed limbs.

(b) Three crops commonly attacked by each

Specimen K (rhinoceros beetle):

1. Oil palm
2. Coconut palm
3. Raffia palm (it also attacks yam, cocoyam and banana)

Specimen L (rat):

1. Cassava
2. Groundnut
3. Cereal grains, whether in the field or in store (it also eats vegetables, oil palm, banana, yam and sweet potato)

(c) Three types of damage caused by each

Specimen K (rhinoceros beetle):

1. It bores into the developing spear and growing point of young oil palm and other palms.
2. The bore holes serve as entry points for secondary rot infection and reduce the quality of the produce.
3. Severe crown damage can kill the growing shoot, causing young palms to break, lodge or die.

Specimen L (rat):

1. It eats up young plants, cereals, groundnuts, roots and tubers of crops.
2. Its burrowing destroys crop roots and causes plants to lodge, reducing yield.
3. It contaminates produce with its faeces and urine, and its gnaw wounds admit secondary infection.

(d) Two ways of controlling each

Specimen K (rhinoceros beetle):

1. Cultural and physical control: hand-pick the beetles from the crown and destroy felled palms and stumps by burning to remove the breeding sites.
2. Chemical or biological control: apply an approved insecticide into the leaf axils, or introduce natural enemies such as the Oryctes virus.

Specimen L (rat):

1. Set traps and rat-proof the store, and use repellents.
2. Poison with rodenticides, or use biological control with predators such as cats.