Predation and Parasitism Flashcards
What percentage of insects are predatory or parasitic?
25%
What is a predator?
An organism that kills and consumes a number of prey animals during its life
What is predation?
The interaction in space and time between predator and prey
Which orders are predators?
Nearly every order has species that are predators
What are parasitoids?
Animals that live at the expense of one other animal host, the host then dies of the interaction
What are parasites?
Animals that live at the expense of another animal host but do not kill the host
What is Parasitism?
Relationship between parasitoid or parasite and the host
What are the two subcategories of parasites and parasitoids?
Ecto living on the outside of and endo living on the inside of
What are the three locating prey strategies used by parasites and predators?
Sit & Wait, Trapping, Active foraging
How do the prey finding strategies rank from most time to least?
Sit & Wait, trapping, active foraging
How do the prey finding strategies rank form most energy to least?
Active foraging, trapping, Sit & Wait
What are the two subcategories of active searching?
Random and Non-Random
What are the three steps to predation/parasitism?
prey/host recognition - Acceptance - manipulation
Is there an optimal prey finding strategy?
No
What are patches?
Discrete areas that are food-resource rich
What are predators that use sit & wait called?
Ambush Predators
What is a good example of trapping behaviour?
Antlion larvae, expends so much energy that they stay in poor nutrients habitat
What is the behaviour of swinging back and forth in random foraging called?
Casting
What happens if a predator encounters a prey while casting?
The predator will increase rate of casting to catch as many prey as possible
What do insects use in directional foraging?
They use cues such as sight, sound, touch, and chemicals
What are stepwise cues?
Certain predators/parasites/parasitoids require a specific series of cues in order to accept the prey/host
What are the chemical cues used in directional foraging?
Kairomones, Synomones, Allomones
What are Kairomones?
cue used for interspecific communication where response to the signal is beneficial to the receiver and not the signaler
What is a Synomone?
interspecific cue that is beneficial to the receiver and the signaler
What is a tritrophic interation?
Its like a third party encounter where one organism is attacking another and a third comes to take away to one initally attacking
What is an Allomone?
Interspecific cue that is beneficial to the signaler but not the receiver
What type of chemical does the bolas spider use in hunting?
Allomone
What adaptation does the female Ormia have that aids in prey finding?
Fused tympani on abdomen
Which species in preyed on by Biosteres longgicandatus using vibrations?
Fruit fly larvae
What adaptations are used in manipulation?
capture and restraining prey, raptorial legs, tubular rostrum, elongate mandibles
What do hemiptera use that make them good hunters?
paralytic and digestive enzymes that they can insert using piercing sucking mouthparts
What are some behavioural techniques useful in manipulating prey?
severing the ventral nerve cord done by a certain kind of beetle
What do some species of ground beetle have that make them good hunters of amphibians?
Double hooked mandibles with paralytic enzymes
What are important factors in host acceptance for parasitism?
identity, size, age, chemical and tactile feeling
What are the different breadths of predator diet?
Monophagous, oligophagous, polyphagous
What are the different breadths of parasite/parasitoid interaction?
Monoxenous (single host for entire life cycle), Oligoxenous (multiple hosts over life cycle), Polyxenous (Capable of infecting multiple species
What are general characteristics of parasitism hosts?
Juveniles
What are key differences between endo and ecto parasitism?
larvae develop in vs out of the host body, eggs laid close to/on vs inside hsot body, ecto avoids immune system problems, ecto is less host specific, endo is more host specific
What are the two types of parasitoids?
idiobionts and koinobionts
What are idiobionts?
kills or paralyzes host, late isntar larvae or puape of prey, develops quickly, often ectoparasites, used by kleptoparasites
What are koinobionts?
lays eggs in young host that continues to grow, parasitoid development can be delayed, host regulation, often endoparasites
What are kleptoparasites?
parasitism by theft, they parasitize a host already parasitized by another
What is host discrimination?
most parasitoids can determine is a host has already been parazitized
What is Superparasitism?
host receives multiple eggs from single or several individuals of the same species
What is Multiparasitism?
Host receives eggs of more than one species
What is Hyperparasitism?
Secondary parasitoid develops at the expense of primary parasitoid
What are the two subgroups of hyperparasitism?
Obligate (can only develop within primary), Facultative (Can also be a primary)
What are the characteristics of Hymenoptera as parasitoids?
adults seek out hosts, sensory info used, sensory receptors on antennae and ovipositor
What are the characteristics of Diptera as parasitoids?
First Instar larvae make host contact, Hypermetamorphosis (first instar larvae is different from others), adults use sensory info
What is the immune response of hosts?
hemocyte activation
What are the two types of hemocytes in host immune system?
granulocytes and plasmatocytes
What are the two things that hemocytes can do to foreign invaders?
aggreagte and form nodules, phagocytize small pathogens, or encapsulate larger parasites or parasitoids
What are the three strategies to combat host immune system
Avoidance (external feeding, eggs not recognized as foreign egg host, enter host organs), Evasion (molecular mimicry using trophamnion) Destruction (Host immune system destroyed/weakened), Suppression (host cellular immune system suppressed by polydnaviruses) and Subversion (feeding on encapsulating sheath or tetratocytes introduce from parasitoid cells)
What are Polydnaviruses?
viruses injected with eggs that shut down the immune response, prevent the formation of host storage proteins and prevent development, virus has symbiotic relationship with parasites
How do fleas and lice differ?
fleas are holometabolic, immatures often free living, lice are paruometabolic, all stages on host, fleas are latterally flattened, lice are dorso-ventrally flattened, both are secondarily wingless, fleas have saltatorial legs, fleas can have ocelli, lice can have chewing mouthparts, lice can parasitize birds as well as mammals, fleas have moderate host specificity, lice have specific host specificity.
