📌 The Question:
Consider the following:

1. Carabid beetles
2. Centipedes
3. Flies
4. Termites
5. Wasps

Parasitoid species are found in how many of the above kinds of organisms?

(a) Only two
(b) Only three
(c) Only four
(d) All five

✅ Correct Answer: (b) Only three

⚡ Lightning Classroom Explanation:

🔹 What is a Parasitoid?
A parasitoid lives in or on a host organism, ultimately killing the host as part of its life cycle. It is evolutionarily closer to predation than parasitism.

🔍 Statement-wise Breakdown:

• 1. Carabid beetles — Correct ✅
  Though rare, some carabid beetles (e.g., Brachinus, Lebia) show parasitoid behaviour, especially at the larval stage.
• 2. Centipedes — Not correct ❌
  Centipedes are active predators, not parasitoids. They hunt and kill prey directly.
• 3. Flies — Correct ✅
  Many flies (Diptera), especially tachinid flies, are classic parasitoids, laying eggs on/in host insects.
• 4. Termites — Not correct ❌
  Termites are detritivores, feeding on dead plant matter. No parasitoid lifestyle.
• 5. Wasps — Correct ✅
  Parasitoid wasps (Hymenoptera) are the most dominant parasitoids in nature, widely used in biological pest control.

➡️ Thus, parasitoid species are found in:
Carabid beetles, Flies, and Wasps = 3 organisms

✔️ Answer: (b) Only three

🧠 Curiosity Raiser:
👉 More than 75% of all known parasitoid species are wasps, making them silent regulators of insect populations.

📚 Enrich Notes (UPSC Edge):

• Parasitoidism is common in:
  • Hymenoptera (wasps)
  • Diptera (flies)
• Used extensively in biological pest control
• Parasitoids differ from parasites because host death is inevitable

🕊️ IAS Monk Whisper:
“Nature controls excess not by force, but by precision.”