Which is the best biological anti-larval measure?

AIIMS CRE SNO - 2023

Community Health Nursing

Easy

Appeared in: AIIMS CRE SNO - 2023

Explanation

The question asks for a biological method that targets the larval stage of mosquitoes.
Gambusia fish (also known as mosquitofish) are living organisms (biological) that are voracious predators of mosquito larvae (anti-larval).
Introducing these fish into stagnant water bodies like ponds, ditches, and ornamental pools is a well-established, effective, and eco-friendly strategy to reduce mosquito populations.
This method directly interrupts the mosquito life cycle before the larvae can mature into adult, disease-transmitting mosquitoes.

Option B: Mineral oils are a physical or chemical control method, not a biological one. They work by forming a film on the water's surface that suffocates the larvae and pupae.
Option C: Sprays typically refer to chemical insecticides used for killing either adult mosquitoes (adulticides) or larvae (larvicides). This falls under chemical control, not biological.
Option D: Anti-mosquito cream is a personal protective measure. It is a chemical repellent applied to the skin to prevent bites from adult mosquitoes; it has no effect on the larval population.

Visual 1: Infographic - A chart comparing different mosquito control methods: Biological (Gambusia fish, Bti bacteria), Chemical (sprays, oils), Physical (draining water), and Personal (nets, repellents). This helps clarify the categories.
Visual 2: Photograph - An image of Gambusia affinis (mosquitofish) in a small pond, with a caption explaining their role in consuming mosquito larvae.
Visual 3: Diagram - The life cycle of a mosquito (egg, larva, pupa, adult), with labels indicating which stage each control method targets.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biological methods for vector control as background academic context rather than a clinical decision trigger.
Community health nurses play a vital role in educating communities about Integrated Vector Management (IVM). This includes promoting sustainable and safe methods like using Gambusia fish over excessive reliance on chemical sprays.
Advocating for biological control helps prevent vector-borne diseases such as malaria, dengue, and chikungunya while minimizing environmental pollution and the risk of insecticide resistance.
What if? If a community reports a sudden outbreak of dengue, the immediate priority might shift to chemical methods like fogging (space sprays) to quickly kill adult Aedes mosquitoes and break the transmission cycle, while long-term larval control measures like using Gambusia fish are also implemented.

How to Approach the Question

First, break down the question. The keywords are 'best', 'biological', and 'anti-larval measure'.
Understand the definitions: 'Biological' means using a living organism. 'Anti-larval' means it acts against the larval stage of an insect.
Evaluate each option based on these two criteria.
Option A: 'Gambusia fish' - A fish is a living organism (biological) and it eats larvae (anti-larval). This is a perfect match.
Option B: 'Mineral oils' - Oil is a substance, not a living organism. It is a physical/chemical method.
Option C: 'Spray' - This usually refers to a chemical insecticide, not a living organism.

Concept Tested & Keywords

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