Lecture 17- Australian invertebrates' diversity II

Question 1

What is the classification of Ants?

Answer 1

P: Arthropoda C: Insecta

O: Hymenoptera (ants, wasps & bees) F: Formicidae (ants)

Question 2

How would you identify insects?

Answer 2

• exoskeleton
• legs not branched
• 1 pair of antennae

Question 3

What are ants diverse in and what things make up diversity?

Answer 3

• Morphological * Ecology / life-history * Number of species / taxa
• -also many ants look like ants!

Question 4

What is the ant diversity of ants in Australia?

Answer 4

Subfamilies: -16World -10 Australia
Genera: 300World 103Australia,
Sp. 15,000World* 1275*Australia
-most are endemic in Australia and very many here!

Question 5

Where do ants live?

Answer 5

• habitat diversity
  1. arid zone: do well as they are small (don’t need much food) are ectothermic, can store food,seed eating is common in ants in Australia, not so in other places
  2. alpine: not as many, not active during very cold periods, have galleries that are deep down where they retreat to, S Aus
  3. temperate woodland: many many species,Ants forage on the ground, but many species also forage in trees & some nest in trees
  4. Wet dry tropics: lots of ants there
• all the ants are similar morphologically but are extremely ecologically diverse, the habitat diversity is along the east coast and lot in tropics

Question 6

What is ants’ sociality like?

Answer 6

• colonial and cooperative, an individual cannot survive outside the colony
• have castes: queen, males are winged, workers are all sterile females (includes all soldiers)
• some species have repletes

Question 7

What are casts like in ants?

Answer 7

• Queen: 1/ nest, she will raise the first badge of eggs, then workers take over • Workers: very large numbers (100s - 10s of 1000s) • Males: never functional part of colony, mate
and die
-Female larvae:
• develop into sterile workers (driven by chemical signals from the queen)
• if queen absent, or if nest very large, some larvae develop into queens
-Castes: avoid interpreting in anthropomorphic context (ants don’t think like us!)
-soldiers are female, large and have big jaws

Question 8

What is communication and cooperation like in ants?

Answer 8

• can cooperate in complex tasks
• can carry large objects together, cooperation
• antennating= communicating ants
• the chemical signal is in the cuticle of the exoskeleton (that is how they recognise one another)

Question 9

What are ant nets like?

Answer 9

• central to colony function
• often underground, holes, digging is energy intensive, many nests last for decades and digging not a problem since have many workers
• they are animals that can modify their environment, built the nests to modify temperature and humidity
• many nest have deep galleries

Question 10

What are the ant plants?

Answer 10

• Ants live in chambers Inside the plant
• mutualism
• often on big emerging rainforest plants
• complex of galleries built by the plant
• plant gets protected and ants have a house that is not going to be damaged by heavy rains

Question 11

What are the meat ants?

Answer 11

• 10 000s of individuals
• characteristic nests, have fine pebbles around the nest entry
• get any rubble etc out of the surrounding area
• big colonies, several hundred meters across
• ability to recognise each other is important

Question 12

What are the characteristics of Green tree ants?

Answer 12

• live in trees in the tropics
• stitch leaves together with silk
• hold it together with their legs

Question 13

What is the diet of ants like?

Answer 13

• predators - scavengers - seeds (quite common in Australia, not very common in other parts of the world, also a mutualistic relationship with acacia)
• often feed on the liquid of victims, some eat nectar (fill up repletes= for bad times)
• can catch live prey or can just find stuff that is dead

Question 14

What is the mutualistic relationship of ants and acacias?

Answer 14

Mutualistic relationships with plants - some ant species:

• feed on oil rich elaiosomes from Acacia - have a role in seed dispersal
• protect the seed, so can germinate away from parent plant in a fertile ground

Question 15

What is the mutualism of Lycaenid butterfly and ants?

Answer 15

• butterfly use the ants as a cue for oviposition
• because often the ants will be on acacia foliage and that is rich in nitrogen (can fix nitrogen)
• butterfly lay their eggs there and the ants protect the larvae and the catepillars secrete nitrogen rich amino acids
• if ants are there the eggs will be lain there (65%)

Question 16

What is the moth larvae parasitism on ants?

Answer 16

• lay eggs and larvae hatch in green ant nests
• the larvae mimic the ants mimically
• the larvae feed on the ants’ eggs
• once they metamorphose they lose the chemical protection and have to fly away quickly

Question 17

What is termite diversity like in Australia?

Answer 17

• families: world-7, Australia- 5

- speceis: world-2300, Australia-348 (15%)

Question 18

What is the classification of termites ?

Answer 18

Termites:
P: Arthropoda
C: Insecta
O: Isoptera (termites)

Question 19

What are the casts like in termites?

Answer 19

• have casts, specialised forms for different role sin the colony
• the workers are sterile female and males
• have winged males and queen
• soldiers are modified workers= large mandibles, larger and sterile

Question 20

Where do termites live?

Answer 20

• termite mounds, many different shapes and places in which they can be
• termite nests may be in trees
• very resistant, built with saliva
• termites are very widespread

Question 21

What is the magnetic termite mound (northern australia)?

Answer 21

• nth-sth orientation helps maintain even internal temp
• when sun overhead, not much surface exposed
• humidity high, up to 95%

Question 22

Where do most termites nest?

Answer 22

• most species nest in timber or underground

- relatively cryptic, hard to see if not the obvious mound above ground

Question 23

Why is the nest important for termites?

Answer 23

-Termite colonies function around their nest (can’t survive alone – similar to ants).
Termites actively maintain temp & humidity in nest
Colony size varies with species - from a few 100 to several million individuals!!

Question 24

What is the termite diet like?

Answer 24

• live & dead timber, grass etc. -Food: poor quality & may have very low water content
• Plant material contains cellulose (rich in sugars) but animals lack cellulases to digest this so utilize a symbiotic protists Trichonympha
• can eat dry grass

Question 25

What is Trichonympha?

Answer 25

• a symbiotic protist, lives in the gut of termites, and has cellulases and can digest cellulose.
• Tiny chips of wood engulfed by symbiotic protists that have cellulases that digest cellulose (producing glucose)

Question 26

Termites summary:

Answer 26

• Very small – total energy needs low
• Invertebrates = ectotherms = lower energy requirements than vertebrates
• Nest maintained at even temp & high humidity, lowers water stress, assists in feeding on food with low water content
• Store food assists in avoiding food shortages e.g. during drought
  Able to exploit nutrient poor & drought prone envit.s