Insect Predators, Parasites, and Parasitoids

Flashcards reviewing the lecture notes on insect predators, parasites, and parasitoids, including their interactions with hosts, predatory strategies, structural features, and parasitoid development.

How do insect predators interact with their prey?

Insect Predators kill and consume multiple prey in their lifetime, resulting in the death of their prey.

How do classical parasites interact with their hosts?

Parasites live on or in their host to get nutrients without killing right away and reproduce faster than their host, weakening or harming the host, but it will survive.

How do parasitoids interact with their hosts?

Parasitoids live on or in a single host and eventually kill the host; the adult is free living, but the larval stage develops within the host, causing the delayed death of the host after development.

List four orders of insects that are predators for all their lives.

Odonata, Mantodea, Neuroptera, and some Coleoptera

Name two families within the order Hymenoptera that are largely predacious and provide an example for each.

Family Vespidae (e.g., yellowjackets, hornets, paper wasps) hunt insects to feed their larvae and Family Formicidae (ants) feed on other insects, small animals, and dead organisms.

Name two families within the order Coleoptera that are largely predacious and provide an example for each.

Family Carabidae (ground beetles) actively feed on other insects, snails, and other invertebrates; Family Coccinellidae (ladybugs) prey on aphids and other soft-bodied insects, both as larvae and adults.

Which orders of insects are frequent exoparasites of vertebrates or feed on vertebrate blood?

Siphonaptera (fleas), Diptera (mosquitoes, black flies, and horse flies), and Phthiraptera (Lice)

Which order of insects contains the majority of parasitoids?

Hymenoptera

List two families within the order Hymenoptera that are parasitoids.

Ichneumonidae (ichneumon wasps) and Braconidae (braconid wasps)

Describe three major strategies by which predators encounter prey.

Sit and wait for prey, trapping prey, and actively searching for prey.

What are the energy investment and expected catch rates for predators that sit and wait for prey?

Low energy investment and long waiting time

What are the energy investment and expected catch rates for predators that trap prey?

Moderate energy investment and more efficient catch per unit time

What are the energy investment and expected catch rates for predators that actively search for prey?

High energy investment and high efficiency

Name two types of sensory cues predators use to locate prey.

Visual cues and olfactory cues

Provide an example of a structural feature found in predatory insects: Raptorial forelegs

Mantids

Provide an example of a structural feature found in predatory insects: Extendable labium with spine-like palpi

Odonata larvae/nymphs

Provide an example of a structural feature found in predatory insects: Raptorial, sickle-like mandible

Carabidae beetles

Provide an example of a structural feature found in predatory insects: Stinger

Wasps

Provide an example of a structural feature found in predatory insects: Piercing mouth parts

Heteroptera

Compare monogenous, oligogenous, and polygenous parasitoids.

Monogenous parasitoids have one host, oligogenous have few hosts, and polygenous parasitoids have many hosts.

What is an advantage for a parasitoid to be monogenous?

Rapid reproduction and specialization in stable environments

What is a disadvantage for a parasitoid to be monogenous?

Lack of genetic diversity and adaptability

What is an advantage for a parasitoid to be polygenous?

Genetic diversity and adaptability in changing environments

What is a disadvantage for a parasitoid to be polygenous?

Slower and energetically costly

Compare solitary and gregarious parasitoids.

Solitary parasitoids have one larva per host, while gregarious parasitoids have several larvae per host.

What are hyperparasitoids?

Parasitoids that parasitize other parasitoids (parasites of parasites)

What sort of parasite immune reaction can kill developing parasitoid larvae?

Encapsulation, where the host’s hemocyte surrounds the parasitoid egg or larva and forms a multilayered capsule, suffocating the parasitoid.

Contrast the development of idiobiont and koinobiont parasitoids in their hosts.

Idiobiont parasitoids prevent the host from further development and paralyze or kill the host, whereas koinobiont parasitoids allow the host to live and develop after being parasitized.

Describe the interaction between the Polydnaviruses, parasitic wasps, and the hosts of the wasps.

Polydnaviruses infect Ichneumonid and Braconid wasps. The viral genome is integrated into the wasp genome, replicated only in the calyx of the wasp ovary. Virions or viral proteins are injected into the parasitoid’s host to suppress encapsulation of the parasitoid.