NORCET 10 Mains: Which of the following is the most effective method for controlling mosquito larvae in water bodies?

NORCET 10 Mains

Community Health Nursing

Easy

Appeared in: NORCET 10 Mains

Explanation

The question asks for the most effective method to control mosquito larvae in water.
Gambusia fish, also known as mosquitofish, are a well-established biological control agent.
These fish are voracious predators of mosquito larvae and are introduced into stagnant water bodies like ponds, ditches, and tanks to consume the larvae.
This method directly interrupts the mosquito life cycle at the larval stage, preventing them from developing into adult mosquitoes.

Option B: This is a broad term. While chemical larvicides can be sprayed on water, 'chemical spray' often refers to fogging or space sprays (adulticides) which target flying adult mosquitoes and have no effect on aquatic larvae.
Option C: Mosquito nets are a physical barrier used for personal protection. They prevent adult mosquitoes from biting people, especially during sleep, but do not control or kill the larvae in water bodies.
Option D: Indoor Residual Spraying (IRS) is an anti-adult measure. It involves spraying insecticides on the interior walls of homes to kill adult mosquitoes that rest on these surfaces after feeding. It does not target the larval stage.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Methods of vector control, specifically targeting mosquito larvae as background academic context rather than a clinical decision trigger.
Understanding vector control is vital for community health nurses in preventing outbreaks of diseases like dengue, malaria, chikungunya, and Japanese encephalitis.
Nurses play a key role in educating communities about integrated vector management, which includes source reduction (eliminating breeding sites), biological control, and personal protection.
In the Indian context, promoting biological controls like Gambusia fish in community ponds and tanks is a sustainable and eco-friendly component of the National Vector Borne Disease Control Programme (NVBDCP).

How to Approach the Question

First, identify the core of the question: it specifically asks for a method to control the 'larval' stage of mosquitoes in 'water bodies'.
Next, evaluate each option against this specific requirement.
Option A (Gambusia fish): Recall or deduce that fish live in water and can eat smaller organisms. Gambusia are specifically known as 'mosquitofish', making them a strong candidate for larval control.
Option B (Chemical spray): Recognize this is a broad term. While some sprays are for larvae (larvicides), many are for adults (adulticides/fogging). It's less specific than Option A.
Option C (Mosquito nets) and Option D (Indoor residual spraying): Identify these as methods that target adult, flying mosquitoes to prevent bites or kill them after they enter a home. They do not affect the larval stage in water.
Conclude that Gambusia fish is the only option that directly and effectively targets mosquito larvae in their aquatic habitat.

Concept Tested & Keywords

Concept Tested: Methods of vector control, specifically targeting mosquito larvae.
Stem keywords: mosquito larvae, control, water bodies
Lead-in keywords: most effective

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E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart B (pp 233-449 of 464) pp. 89-91, 88-90