Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Behavioural Ecology
Insects
| Question | Answer |
|---|---|
| What are insects? | Phylum Arthropoda hardened chitinous exoskeleton that moults Clade Mandibulata antennae body divided into head, thorax, abdomen |
| What are insects? | Subphylum Hexapoda 3 pairs of jointed legs Class Insecta 2 pairs of wings (* can be secondarily lost) 1 pair of antennae |
| Services to the ecosystem | - pollination - dung removal - pest control - carrion breakdown - food |
| State | Up to 75% decline in the last fifty years |
| Biomimetrics | The transfer of ideas and analogues from biology to technology |
| Insects exhibit behaviours that all animals share, including humans | Navigation Copying, learning and teaching Communication Parental care Context-dependent decision making |
| Insects exhibit behaviours that all animals share, including humans | Co-ordination Memory Courtship and mating Anti-predator behaviour |
| Monarch butterfly navigation | Up to 3000 km travelled No single individual completes the trip 4 generations in the complete annual cycle |
| Learning and memory in bumblebees | Bees have to navigate complex spatial environments Need to remember floral resources Bees can be taught simple tasks in the lab And can learn by watching other bees (or bee-shaped models) |
| Why study insect behaviour? | Goal of behavioural ecology: “explain the survival and reproductive value (i.e. the evolutionary significance) of behavioural traits - measure lifespan + lifetime reproduction |
| Aggression and weaponry | Sexually selected traits constitute some of the most eye-catching morphologies In lots of species, one sex (typically but not always the male) invests in weapons which are used in contests |
| Fighting is costly | Damage and injury to the aggressor and defendent is common - wings, beetle weaponry - so must weigh up the pros and cons of engaging - defensive armour assists, males similar in size and with females around more likely to engage |
| The winner effect | If an insect has won before, they are more likely to engage in fights - induces hyperaggression |
| Trade-offs: Insects must balance reproduction with survival | Big weapons help males win fights But also increase the risk of predation |
| Insects must balance reproduction with survival | One anti-predation strategy is autotomy ‘The self‐controlled loss of a body part at a predetermined breakage location’ |
| The capacity to autotomize is widespread across hemipterans | Some species drop their legs faster than others It’s common to find individuals missing one (or more!) limbs in the wild |
| Autotomy not just enables escape | But also increases survival after injury |
| But it comes with costs in other areas | Autotomy doesn’t affect how likely males are to engage in fighting But it does increase the likelihood they lose |
| If males can’t fight, how can they produce offspring? | Invest in sperm production rather than weaponry? |
| Is there a trade-off between weapons and testes? Can we measure it? | Insect systems are providing answers The earlier autotomy limb loss occurs, the bigger a male’s testes are - trade-off |
| Autotomy induces an increase in average mating duration | Increased sperm transfer? Mate guarding? |
| We can track how morphology and behaviour interact | Morphology - Reallocation ↓ after adulthood As resources available ↓ As developmental flexibility ↓ |
| We can track how morphology and behaviour interact | Behaviour - potentially maximise the pay-off of larger testes |
| Plasticity in reproductive allocation is widespread in insects = Males can | Adjust ejaculate size based on female mating status, fecundity, and age (Lupold et al. 2010) Produce more sperm produced in response to the presence of rivals (Moatt et al. 2014) |
| Plasticity in reproductive allocation is widespread in insects = Males can | Grow bigger testes if reared at high larval densities (Stockley & Seal 2001) Grow bigger testes if they hear adult males (Bailey et al. 2010) |
| Trade-offs throughout behavioural ecology | Individuals must balance costs and benefits of all behaviours When should they fight? How much should they invest in weapons vs testes? How much should they risk predation for mating opportunities? How many risks should they take? |
Created by:
rose.coo
Popular Ecology sets