Question

Which of the followings are related with San Jose scale?
(A) Insect feed on root of grapes
(B) First documented case of insecticide resistance
(C) Hemipterous insect
(D) Quadraspidiotus perniciosus
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (B) and (C) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

Remember the historical milestone of San Jose scale (Quadraspidiotus perniciosus):
It is the first insect in scientific history recorded to have developed resistance to a chemical pesticide (lime-sulfur, in 1914).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
San Jose scale is an economically destructive pest of deciduous fruit trees (primarily apples, pears, and peaches) worldwide.
Understanding its scientific classification, historical significance, and biology is essential in agricultural entomology.

Step 2: Detailed Explanation:
Let us evaluate each statement:
- Statement (D) is correct: The scientific name of the San Jose scale is Quadraspidiotus perniciosus (previously known as Aspidiotus perniciosus).
- Statement (C) is correct: It belongs to the order Hemiptera (true bugs) and family Diaspididae (armored scale insects). It is a hemipterous sap-sucking insect.
- Statement (B) is correct: Historically, the San Jose scale is famous for being the first documented case of insecticide resistance in the world.
In 1914, A.L. Melander reported that the insect had developed resistance to lime-sulfur sprays in the state of Washington, USA.
- Statement (A) is incorrect: San Jose scale primarily infests the twigs, branches, leaves, and fruits of deciduous trees (especially apple orchards in India, like in Jammu & Kashmir and Himachal Pradesh).
It does not feed on the roots of grapes. The insect that feeds on grape roots is the Grape Phylloxera (Daktulosphaira vitifoliae).
Therefore, statements (B), (C), and (D) are correct, while (A) is incorrect.

Step 3: Final Answer:
The correct option is (D).