Best biological method to control larva?

Appeared in: NORCET 2 -2021 (Shift-2)

Explanation

Gambusia fish, also known as mosquitofish, are a primary biological agent used for mosquito control.
They are larvivorous, meaning they feed voraciously on the aquatic larval and pupal stages of mosquitoes.
Introducing these fish into stagnant water bodies like ponds, ditches, and tanks is an effective, self-sustaining, and environmentally friendly way to break the mosquito life cycle.
This method targets the source of the mosquito population, reducing the number of adults that can transmit diseases.

Option A: DDT spray is a chemical method of control, not biological. It is also primarily an adulticide, used to kill adult mosquitoes, not larvae.
Option C: Using a mosquito net is a form of personal protection that acts as a physical and chemical barrier against adult mosquitoes. It does not control the larval population.
Option D: Applying repellent ointment is a personal protective measure that deters adult mosquitoes from biting. It has no effect on the larval stage of the mosquito life cycle.

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, specifically for mosquito larvae as background academic context rather than a clinical decision trigger.
Community health nurses play a vital role in educating the public about Integrated Vector Management (IVM) to prevent diseases like malaria, dengue, and chikungunya.
Understanding the difference between larval control (source reduction) and adult mosquito control is crucial for providing effective health education and implementing community-wide prevention programs.
Nurses can advise communities on identifying and eliminating breeding sites and advocate for sustainable control methods like using Gambusia fish in community water tanks or ponds.

How to Approach the Question

First, dissect the question to identify the core requirements. The keywords are 'Best', 'biological method', and 'control larva'.
Understand the term 'biological method'. This means using a living organism (a natural predator or parasite) to control a pest.
Recognize that 'control larva' specifies the target is the aquatic, immature stage of the mosquito, not the flying adult.
Evaluate each option against these three criteria.
Option A (DDT) is a chemical, not biological. Eliminate it.
Option C (Mosquito net) and D (Ointment) are for personal protection against adult mosquitoes, not larval control. Eliminate them.

Concept Tested & Keywords

Concept Tested: Biological methods for vector control, specifically for mosquito larvae.
Stem keywords: biological method, control larva
Lead-in keywords: Best
Negative lead-in flag: false

Q-SGbx43sac7S3orZl-GoR

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

Practise the full NORCET 2 -2021 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.