Question

Name the weed destroyer moth imported from Argentina and introduced in Australia during the year 1925

• A. Lantana sp
• B. Orthezia insignis
• C. Cactoblastis cactorum
• D. Opuntia sp

Hint:

Always remember: Cactoblastis is the "Cactus Blaster." It blasts the prickly pear (Opuntia) away.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Biological control involves the introduction of a natural enemy (insect, fungus, or bacteria) to suppress the population of an invasive pest or weed.
Detailed Explanation:
In the early 1900s, Australia faced an ecological disaster.
The prickly pear cactus (Opuntia spp.) had spread across 60 million acres of farmland, making it impenetrable and useless for grazing.
Since the cactus was native to the Americas, it had no natural enemies in Australia.
After extensive research, scientists identified a moth in Argentina whose larvae feed exclusively on this cactus.
This moth was Cactoblastis cactorum.
It was introduced into Australia in 1925.
The larvae of Cactoblastis tunnel into the cactus pads, eating them from the inside and introducing rot-causing bacteria and fungi.
The results were spectacular. Within 10 years, the vast majority of the prickly pear had been destroyed, and the land was reclaimed for agriculture.
This remains one of the most successful examples of classical biological control in history.
Note: Opuntia is the weed being controlled, not the moth.

Step 2: Final Answer:
The moth is Cactoblastis cactorum.