Which invasive coleopteran was imported to North America for pest control but became a pest itself?

Which invasive coleopteran was imported to North America for pest control but became a pest itself?

• A. Asian lady beetle (Harmonia axyridis).
• B. Colorado potato beetle (Leptinotarsa decemlineata).
• C. Japanese beetle (Popillia japonica).
• D. Lady beetle (Coccinella septempunctata).

Answer: (C)

This question centers on what happens when a biological control agent is released to manage pests but ends up becoming a pest itself. The risk with deliberate introductions is that the organism may spread beyond the target pests, outcompete native species, disrupt ecosystems, or become a nuisance to humans. The classic example is Harmonia axyridis, the Asian lady beetle. It was released in North America to help suppress aphids and other garden pests, and it established itself across wide areas. Over time it became a nuisance in homes during colder months, and it also competes with native lady beetles, altering local predator-prey dynamics. This illustrates the core idea: a biocontrol agent can turn into an invasive pest, highlighting why such releases require careful risk assessment and monitoring. In the options listed, the general concept is best exemplified by the idea of a biocontrol beetle turning into a pest, with the Asian lady beetle serving as the key real-world instance of that outcome. The other beetles are either pests in their own right due to accidental introductions or native pests, not classic biocontrol introductions that backfired in the same way.

This question centers on what happens when a biological control agent is released to manage pests but ends up becoming a pest itself. The risk with deliberate introductions is that the organism may spread beyond the target pests, outcompete native species, disrupt ecosystems, or become a nuisance to humans.

The classic example is Harmonia axyridis, the Asian lady beetle. It was released in North America to help suppress aphids and other garden pests, and it established itself across wide areas. Over time it became a nuisance in homes during colder months, and it also competes with native lady beetles, altering local predator-prey dynamics. This illustrates the core idea: a biocontrol agent can turn into an invasive pest, highlighting why such releases require careful risk assessment and monitoring.

In the options listed, the general concept is best exemplified by the idea of a biocontrol beetle turning into a pest, with the Asian lady beetle serving as the key real-world instance of that outcome. The other beetles are either pests in their own right due to accidental introductions or native pests, not classic biocontrol introductions that backfired in the same way.