predation and parasitism

Question 2

what is predation

Answer 2

the killing and consumption of multiple prey with positive effects of predator or parasite and negative of prey/host
= applies to carnivorus plants/herbivores whcih kill plants seeds and seedlings

Question 3

define intraguild predation and cannabilism

Answer 3

1) predation on other predators with shared prey resource
2) predation within species

Question 4

define predator functional responce

Answer 4

how individual rate of prey consumption changes
- affected by ability to catch and handle prey
- numerical response of predators can be caused as prey densities grow

Question 5

what are the three types of responces identifyed by Holling 1959 in terms of the effect of predators and prey

Answer 5

Type 1 = consumption rate is limited only by the prey densitiy = prey capture constant and independant of prey desity

2- proportion prey captured decreases as prey desnity increases = limited by ability to find and process food

3- takes into account prey switiching and learning

Question 6

what is meant by the term haematophagy

Answer 6

blood feeding
1) pool feeding - biting mouthparts cut open superfical blood vessels and feed on blood which leaks out
2) piercing and sucking = specalised mouthoparts which inserted into skin and blood vessels severed

= act as vectors of many parasites and pathogens

Question 7

what is a faculative haematophage

Answer 7

species which aquire at least some portion of thier nutrition from non blood sources in at least one of the sexually mature forms
= many insects blood meal is needed before laying eggs whilst males feed on nectar

Question 8

outline some blood feeding species and the disease/parasites that they spread

Answer 8

Sandflies = leishmaniasis
Tsetse flies = trypanomiasis
black flies = parasitic nematode

Question 9

give some examples of obligatory blood feeders

Answer 9

• assassin bugs = chagas disease
• lice
• fleas= transmits bubonic plague

Question 10

outline some plant eating insects

Answer 10

grow in nutrient poor areas= especially nitrogen
- over 583 spp = wide spread but rare
- six different trapping mechanisms

Question 10

what are the 6 trapping mechanisms employed by plant eating insects

Answer 10

flypaper, fixed/mobile tentacles, pitfall, lobster pot, pigeon trap, snap and suction

Question 10

how do sundw species capture insects

Answer 10

ADHESIVE = trap using long mobile mucilage secreting glands
= sticky substance attracts and traps
= weight + movement triggers hairs to wrap around

Question 10

why do insect eating plants have decreased photosynthesis

Answer 10

leaf used as trap = less efficient for photosynthesis
- energy expended on non-photosynthetic structures such as glands and digestive enzymes
= decreased photosynthesis and increased respiration

Question 10

how do butterwort species capture insects

Answer 10

flypaper (adhesive trap) = bright yellow-green leaves excrete sticky fluid which attracts inects
- leaves curl around and digest it
- acidic bogs, fens and damp heaths

Question 11

how does bladderwort species capture insects

Answer 11

suction = found submerged in still fresh water
- bladders pump out ions water follows by osmosis creating partial vaccum

Question 12

what is parasitism

Answer 12

organisms living in or on another obtaining nurtirion and causing damage to the host
= parasitoid eggs or larvae in host
= 70% british spp parasitic

Question 13

how does a small body size help parasites

Answer 13

means more habitat available

Question 14

outline parasite host specificity

Answer 14

• highly specific and adapted to one host spp
• close relationship of life cycles between para and host = even higher specificty
  = specificty linked to adaptive radiation = rapid diversification to exploit new resources

Question 15

what is a kelptoparaiste

Answer 15

lay eggs in host nests and larvae consume host egg or larvae while young then food provided by the host for its own juvinile
e.g.
cuckoo bees on leaf cutter bees

Question 16

what are insect brood parasites

Answer 16

e.g. large blue butterfly
= larvae produce allomones that mimic ant larvae causing ants to carry then into nest and feed them
= sometumes predate on ant larvae

Question 17

define superparasitism

Answer 17

host recives multiple eggs from one of more individual

Question 18

what are some ecosystem services provides from predation and parasitism

Answer 18

1) bio control
- reduction of pest populations by natural enemies
3 categories

Question 19

what are the three categories of bio control

Answer 19

1) conservation
2) classical bio control
3) augmentation

Question 20

outline conservation as a category of bio control

Answer 20

used to optmise survival and or effectiveness of natural enemies
= reducing insecticide applications
= staggering harvest dates to ensure constant supply of hosts
= providi9ng shelter, over wintering sites or alternative food suplly

Question 21

outline classical bio control

Answer 21

1) ID BCA from natural enemy in countru
2) ensure ecology and host range compatible
3) select BCA which can be easily reared
4) release in large numbers into crop so it becomes established and supressed pest pop

Question 22

what is augmentation

Answer 22

entauls the supplemental release of natural enemies in two strat
1_ inoculative = few released at critical times
2- inundative = millions released

Question 23

what are the charatceristics of a successfull BCS

Answer 23

narrow host range = generalised pred may be good but do not kill enough pests when other prey types available

climatic adaptibility = natural enmyy must survive extremes of new habitat

synchrony with host/prey

high repro potential

efficcent searcg abulity = able to locate

short handling time = consume prey rapidly

survive low host prey density