Consider the following : 1. Carabid beetles 2. Centipedes 3. Flies 4. Termites 5. Wasps Parasitoid species are found in how many of the above kind of organisms ?

• A parasitoid is an organism whose larva develops on or inside a single host and ultimately kills it — unlike a true parasite, which usually keeps its host alive.

• Wasps are the classic parasitoids (ichneumonids, braconids, chalcids), laying eggs in caterpillars and aphids and widely used in biological pest control — item 5 qualifies.

• Many flies, especially the tachinids, are parasitoids of caterpillars and beetles — item 3 qualifies; some carabid (ground) beetle larvae are parasitoids of other insects — item 1 qualifies.

• Centipedes are free-living predators and termites are social wood-feeders; neither has parasitoid species — items 2 and 4 do not qualify.

• Hence three of the five, option (b).