Question

Viviparity is observed in?

• A. Whiteflies
• B. Aphids
• C. Thrips
• D. Mites

Hint:

Viviparity and telescoping generations are the primary biological drivers behind the rapid, explosive population growth of aphids in field crops.
Remember that this strategy is highly adaptive for exploiting temporary, nutrient-rich food resources.

Answer 1

The Correct Option is B

Viviparity is a reproductive mechanism in animals where the female gives birth to active, living young instead of laying eggs.
In insects, this is an advanced evolutionary adaptation that bypasses the highly vulnerable egg stage.
By protecting the developing embryo inside the maternal body, the species reduces egg mortality caused by desiccation, pathogens, and predators.

Step 2: Detailed Explanation:
Aphids (Order Hemiptera, Family Aphididae) are small, soft-bodied plant-sucking insects known for their complex and highly adaptable reproductive cycles.
During the spring and summer months, when environmental conditions are optimal and host plants are abundant, aphids display a phenomenon known as cyclical parthenogenesis.
During this asexual phase, virgin female aphids do not require mating to reproduce.
Instead of laying eggs, they give birth directly to live, active nymphs (viviparity).
This process is accompanied by the biological phenomenon of "telescoping generations," where a developing female embryo inside the mother already contains its own developing embryonic offspring.
This dual adaptation of parthenogenesis and viviparity allows aphid populations to expand exponentially in a very short span of time, often leading to rapid pest outbreaks in agricultural crops.
When winter approaches, aphids transition to sexual reproduction and lay overwintering eggs (oviparity) to survive the harsh cold.
Let us contrast this with the other options:
- Whiteflies (such as Bemisia tabaci) and Thrips (such as Thrips tabaci) reproduce primarily by laying eggs on the undersides of leaves (oviparity).
- Most agricultural mites (such as tetranychid spider mites) are also oviparous, laying microscopic spherical eggs on silk webs or leaf surfaces.

Step 3: Final Answer:
Thus, viviparity is characteristically and prominently observed in aphids during their asexual multiplication phase.