Lecture 29

Question 1

mutualism

Answer 1

an ecological interaction b/w spp that benefits both interacting spp

Should be better off through their engagement than without it

Question 2

what are 3 exs of insect mutualism?

Answer 2

Pollination: bees & plants

Improved nutrition of blood: sucking lice, bed bugs, tsetse flies, etc. & microbes
Have special microbes in their gut enabling the digestion of blood

Farming?

Question 3

describe how humans farming cattle is a mutualistic relationship

Answer 3

Humans use livestock to process low quality food (grass etc.) into high quality food (meat, milk, etc.)

Livestock benefit b/c here are more cattle b/c of farming

Question 4

Ants locate aphid groups & control them by: (3)

Answer 4

Herding behaviour
Maintain aphids in areas of younger parts of plants b/c it is more nutritious

Wing removal of alate aphids
Aphids can be polymorphic – ants don’t want the aphids to leave so they remove their wings

Secretion of chemicals that slow aphid walking

Question 5

how do ants protect aphids against their aggressors (predators/parasitoids)?

Answer 5

Attacking with their mandibles (Ladybeetles have a protective body shape)

Spraying formic acid

Question 6

who is a parasitoid of aphids?

Answer 6

hover fly larvae

Question 7

how do ants harvest the aphids?

Answer 7

“milk” aphids by swallowing excreted droplets of honeydew

occasionally eat aphids when their demand for PRO is required

Question 8

what is the carb-rich material secreted by aphids that ants harvest?

Answer 8

honeydew

Question 9

Ants travel from aphid herds to nests aided by ____ ____

Answer 9

trail pheromones

Question 10

how do ants transfer their food to other ants?

Answer 10

trophallaxis

Drink the honeydew & transfer it to other ants orally

Question 11

trophallaxis

Answer 11

Ant to ant food transfer (oral transfer)

Question 12

T or F - all ants can act as storage

Answer 12

T

Question 13

what are repletes?

Answer 13

honey pod ants have a caste (social stratification) where these ants are specialized to store food for times of shortage by expanding their membranes

Question 14

how are the repletes emptied?

Answer 14

trophallaxis

Question 15

when are repletes used?

Answer 15

When production is higher than demand they store the honeydew

Question 16

what are the 2 food sources that honey pod ants harvest?

Answer 16

honeydew

nectar

Question 17

only the ____ tribe of ants farm for fungus

Answer 17

Attini

Question 18

where are the Attini ants distributed?

Answer 18

Central & South America

Question 19

who are the equivalents in Africa & Asia to Attini ants?

Answer 19

termites

Question 20

Attini tribe has an _______ ________ on _____ _____ for food

Answer 20

obligate dependence

symbiotic fungi

Question 21

Atta nests up to _____ tons of soil

Answer 21

40 tons of soil

Question 22

what spp of ants have polymorphic spp (castes of workers specialized)? & what is the form of polymorphism?

Answer 22

Atta & Acromyrmex

polymorphic size

Question 23

_____% leaf damage & ____% biomass consumption in rainforests (most productive ecosystem)

Answer 23

80%

17%

Question 24

In grasslands Atta spp consumes the same biomass of vegetation per hectare as _____

Answer 24

cattle

Question 25

what % of cellulose is converted in carbs by Atta spp?

Answer 25

45%

Question 26

Describe how ants make their fungus nests

Answer 26

A. ants harvest leaf pieces Done with powerful mandibles Requires a lot of force Acquired with quick shivering movement of mandibles B. Pheromone trail of transporter workers Go into nest C. Transporter workers give pieces to processing workers Bring material to fungus garden D. Leaf pieces converted to mulch substrate for fungal growth (chew) Fungus produces gongylidia which are food for ants E. The queen sits on the fungus garden laying her eggs Larvae eat the gongylidia & are cared for by nurse workers F. Waste leaf material, dead ants & dead fungus are transported to dump chambers Located separately from gongylidia

Question 27

gongylidia

Answer 27

specialized structure produced by the fungus to provide ants with a food source

Question 28

does the fungus benefit by creating gongylidia?

Answer 28

nope

Question 29

gongylidia are rich in _____

Answer 29

carbs

Question 30

the separation of waste materials provides what ecological service?

Answer 30

important for fertility of soil

Question 31

Fungus growth in ideal conditions of _________, __________ & _________

Answer 31

temperature, humidity & darkness

Question 32

how do ants encourage the growth of the fungus?

Answer 32

remove wax on plant material

Question 33

what compound does the fungus feed on?

Answer 33

cellulose

Question 34

what crop management do ants practice?

Answer 34

Fertility management Waste management Cultivar selection & monocultures

Question 35

Collection of ______ leaf fragments/year

Answer 35

6000kg

Question 36

do ants feed on a variety of fungi spp?

Answer 36

no

Question 37

how does the queen ant est her colony?

Answer 37

Before a mating flight, a queen collects a small amount of fungus in her mouth She carries the fungus until she establishes a nest, then uses it to start a new fungus garden After mating the queen stores 206 – 320 million sperm (last ~10 years of queen life) Female will make a tunnel, leave some fungi, lay eggs & has workers to begin the colony

Question 38

In the most evolved fungal farmers, the fungus ________

Answer 38

cannot survive without the ant

Question 39

Each ant grows a _____ range of fungal cultivars

Answer 39

narrow

Question 40

describe pest management strategies

Answer 40

can be invaded by other fungi & bacteria Gardeners weed the garden & secrete compound that promote fungal growth & suppress pests

Question 41

describe the role of the fungicide producing bacteria

Answer 41

Patches of bacteria on thorax of ant Produces fungicide compounds that attacks pest fungus Queens on mating flights carry bacterial fungicide producers to use in the new colony

Question 42

Myrmecochory

Answer 42

seed dispersal by ants

Question 43

Elaiosomes

Answer 43

food bodies on seeds with chemical attractants for ants nutritious & easy for ants to eat

Question 44

Elaiosomes are present in plants of what distribution?

Answer 44

Australia & Africa

Question 45

how do elaiosomes spread?

Answer 45

Soft structure, but seeds are hard to the ants so they move the seeds to the waste chambers ants carry them to the nest but are hard so they're discarded