Lecture 17- Australian invertebrates' diversity II Flashcards
What is the classification of Ants?
P: Arthropoda C: Insecta
O: Hymenoptera (ants, wasps & bees) F: Formicidae (ants)
How would you identify insects?
- exoskeleton
- legs not branched
- 1 pair of antennae
What are ants diverse in and what things make up diversity?
- Morphological * Ecology / life-history * Number of species / taxa
- -also many ants look like ants!
What is the ant diversity of ants in Australia?
Subfamilies: -16World -10 Australia
Genera: 300World 103Australia,
Sp. 15,000World* 1275*Australia
-most are endemic in Australia and very many here!
Where do ants live?
- 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
What is ants’ sociality like?
- 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
What are casts like in ants?
• 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
What is communication and cooperation like in ants?
- 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)
What are ant nets like?
- 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
What are the ant plants?
- 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
What are the meat ants?
- 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
What are the characteristics of Green tree ants?
- live in trees in the tropics
- stitch leaves together with silk
- hold it together with their legs
What is the diet of ants like?
- 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
What is the mutualistic relationship of ants and acacias?
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
What is the mutualism of Lycaenid butterfly and ants?
- 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%)
What is the moth larvae parasitism on ants?
- 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
What is termite diversity like in Australia?
- families: world-7, Australia- 5
- speceis: world-2300, Australia-348 (15%)
What is the classification of termites ?
Termites:
P: Arthropoda
C: Insecta
O: Isoptera (termites)
What are the casts like in termites?
- 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
Where do termites live?
- 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
What is the magnetic termite mound (northern australia)?
- nth-sth orientation helps maintain even internal temp
- when sun overhead, not much surface exposed
- humidity high, up to 95%
Where do most termites nest?
- most species nest in timber or underground
- relatively cryptic, hard to see if not the obvious mound above ground
Why is the nest important for termites?
-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!!
What is the termite diet like?
- 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
What is Trichonympha?
- 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)
Termites summary:
- 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
