Question

Predominant vector of leaf curl disease infesting vegetable crops is:

• A. Mites
• B. Whiteflies
• C. Aphids
• D. Flea beetles

Hint:

Vegetable leaf curl diseases are caused by Begomoviruses, which are transmitted specifically by the whitefly vector (Bemisia tabaci) in a persistent, circulative manner.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Leaf curl diseases are among the most destructive viral diseases affecting solanaceous and cucurbitaceous vegetable crops (such as tomato, chilli, and papaya).
These diseases are caused primarily by Begomoviruses, which belong to the Geminiviridae family.
The transmission and spread of these viruses are driven by specific sucking insect vectors.

Step 2: Detailed Explanation:
The whitefly, Bemisia tabaci (family Aleyrodidae), is the predominant vector of Begomoviruses causing leaf curl diseases.
During feeding, the whitefly inserts its stylet into the phloem cells of an infected plant, ingesting the virus particles along with the sap.
The virus is transmitted in a persistent, circulative manner.
Once ingested, the virus passes through the insect's gut wall into the hemolymph and eventually reaches the salivary glands, from where it is injected into healthy plants during subsequent feeding.
Because of the high reproductive rate and wide host range of whiteflies, leaf curl diseases can spread rapidly in vegetable-growing regions, causing severe leaf curling, stunting, and yield losses.
Other vectors like aphids or mites can transmit different viruses, but whiteflies are the primary vector for leaf curl Begomoviruses.

Step 3: Final Answer
The predominant vector of leaf curl disease in vegetable crops is the whitefly.