Correct option is C
Parasitoids are organisms (commonly insects like certain wasps or flies) that spend a significant portion of their life attached to or within a single host organism, which they eventually kill.
Parasitoids differ from:
-Parasites, which usually do not kill the host.
-Predators, which often kill the host immediately.
Option 3: Intrinsic rate of population growth comparable to hosts; Eventually fatal for the host- Correct
Parasitoids typically evolve life-history traits synchronized with their host's lifecycle. Their intrinsic growth rate is comparable to the host to maintain a stable interaction and maximize survival, and they are eventually fatal to the host — not immediately.
Incorrect Options:
Option 1:Intrinsic rate of population growth faster than hosts; Eventually fatal for the host
A faster population growth rate can lead to overexploitation of host populations.
This can create host-parasitoid population crashes, where too many parasitoids quickly deplete available hosts.
Natural selection favors more regulated dynamics, not explosive parasitoid populations.
Ecological theory and empirical data support that synchrony is key — not rapid overgrowth.
Option 2:Intrinsic rate of population growth slower than hosts; Immediately fatal for the host
Parasitoids require the host to stay alive for a certain period during their development. Immediate death of the host would mean the parasitoid could not complete its life cycle.
Additionally, if their population grows slower than hosts, they may fail to keep up with host availability or control host numbers effectively.
This combination (slow growth + immediate killing) is more characteristic of lethal pathogens or predators, not parasitoids.
Option 4:Intrinsic rate of population growth faster than hosts; Immediately fatal for the host
Parasitoids are not immediately fatal. They require the host to survive during their larval or developmental stages.
Killing the host immediately would prevent completion of the parasitoid’s life cycle.
Also, faster growth plus immediate fatality aligns more with predator-prey or pathogen-host dynamics — not parasitoid-host relationships.
