Question

Which of the following nematode is on the international quarantine list in India?

• A. Bursaphelenchus xylophilus
• B. Heterodera zeae
• C. Pratylenchus zeae
• D. Heterodera avenae

Hint:

Remember that quarantine pests must be exotic to the importing nation. Pests that are already widespread in India (like Heterodera avenae or Heterodera zeae) cannot be on the quarantine list.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Quarantine regulations are designed to prevent the introduction of destructive, non-native (exotic) pests and diseases into a country.
Quarantine lists include high-risk organisms that are not yet established in the importing country but pose a threat to agricultural and forestry resources.

Step 2: Detailed Explanation:
Let us review the status of each nematode listed:
1. Bursaphelenchus xylophilus (Pine Wilt Nematode):
This nematode is native to North America and causes pine wilt disease, which is highly destructive to pine forests, particularly in Asia (such as Japan, China, and Korea) and parts of Europe.
It is transmitted from tree to tree by wood-boring beetles in the genus Monochamus.
Because India has vulnerable pine forests in the Himalayan region and the nematode is not yet established in the country, it is classified as a regulated quarantine pest.
Strict import checks are maintained on timber, wood packaging materials, and plants to prevent its introduction.
2. Heterodera zeae (Corn Cyst Nematode):
This nematode is widely distributed and established in major maize-growing regions in India.
As a native or established pest, it is not on the import quarantine list.
3. Pratylenchus zeae (Lesion Nematode):
This species is commonly found in India, particularly in sugarcane and cereal crops, and is not a quarantine pest.
4. Heterodera avenae (Cereal Cyst Nematode):
This nematode causes "Molya disease" in wheat and barley.
It is already established in several Indian states, such as Rajasthan, Haryana, and Punjab, and is not on the quarantine list.
Thus, Bursaphelenchus xylophilus is the quarantine pest on this list.

Step 3: Final Answer:
The pine wilt nematode, Bursaphelenchus xylophilus, is on India's international quarantine list.
Thus, the correct option is 1.