Neuron
Nervous system cell
Dendrite
Branched part of neuron that receives signals
Axon
long fiber that the signal is sent down
synapse
gap that separates axon from dendrite
Neurotransmitter
chemical compound that passes across synapse
Similarities between insect and human nervous systems and how electrical signals are sent through the system
they are basically the SAME!
1) Sodium atoms (ions) build up outside the neuron due to active pumping of special proteins
2) These ions have "potential energy" and naturally want to flow down the concentration gradient
3) special channels are designed to
**how organophosphate (OP) insecticides work
OPs inhibit acetylcholinesterase and nerve impulses keep firing
Organochlorine compounds work on insects by opening what's known as the sodium ion channel in the neurons or nerve cells of insects, causing them to fire spontaneously. The insect will go int
Traumatic insemination
Male uses aedeagus and stabs female in abdomen or even head!
Spermethica
to receive and store sperm from the male
aedeagus
a reproductive organ of male arthropods through which they secrete sperm from the testes during copulation with a female
Oviparity
egg-laying
Eggs are expelled from ovaries (ovulation); met with sperm stored in spermatheca as it travels from oviduct to vagina (fertilization); and finally ejected from the body and deposited on an external surface
Ovoviviparity
eggs incubated inside female
then fully developed eggs or recently eclosed young are laid
Adenotrophic viviparity
Larva ecloses within mother
Larva develops in "uterus"
Feeds from "milk" glands
Termite egg laying
can produce 30,000 eggs/day
164.25M eggs in a lifetime!
Heterotrophs
things that must consume other things
Bacteria, Archaea, Eukarya
Animalia, Fungi, Protista (most)
Chordata (us) & Arthropoda
Autotrophs
make their own food, but consume it on a cellular level the same as heterotrophs
Bactera (cyanobacteria "algae"), Protista (algae, kelp), Plantae
what parts of the insect digestive system get molted
Foregut and hindgut are actually part of the exoskeleton and shed during molt!
Human circulation vs insect circulation
Human - Body cavity is filled with organs
Heart pumps blood
Blood flows through arteries and veins
Hemoglobin in red blood cells carries oxygen in and C02 out
Blood also serves immune function and carries nutrients in and wastes out (gas, liquid, solid)
I
Insect blood name and functions
Hemolymph - Not used for oxygen transport
Transport nutrients, hormones, non-gas wastes
Provide hydraulic pressure
Provide immune response to invaders
Spiracles
Openings in exoskeleton
Allows gas exchange
Get oxygen into the body, waste gases out
Keep water in - also keep water out
Trachae and tracheoloes
are flexible but strong tubes that deliver oxygen to cells and remove CO2
Limited insect size
Insect size is limited by how much oxygen they can get through the tracheae, in ancient times of the griffinflies oxygen levels dictated that insects could be larger than today!
Same amount of oxygen,
harder to move through
Same in a large animal -
couldn
Plastron
air trapped near spiracles
Gills
Thin exoskeleton allows gas exchange to internal tracheae
Modified Spiracles
Work like snorkels to reach the air
How does metabolism work?
Metabolism uses respiration to harvest energy from food molecules and aerobic respiration carries away waste carbon as CO2
Thermoregulation
Keeping body temperature within tolerable limits - when organisms get too hot or too cold they will die! Enzymes stop working within the cell!
Proteins work in a narrow range of temperatures
Too hot - proteins denature
Too cold - enzymes do not function
Poikilothermy
All arthropods are considered to have this type of thermoregulation even though there are some examples that push the bounds.
Body temperature is regulated externally and body heat comes from environment alter body heat by behavior.
Body size limited
Narr
Homeothermy
Larger body size
Broader "working" environmental temperature range
Must eat lots of calories
Ways insects survive and regulate body temp during seasonal extremes
1. Migration
2. Spatial Freeze Avoidance - huddle together/dig in somewhere compact
3. Physical Freeze Avoidance - Spin yourself a blanket. Create chemicals that prevent freezing!
5. Internal Freeze Tolerance
6. Insect Hibernation AKA DIAPAUSE terms for r
Story about an insect strategy for overwintering
Monarchs take several generations to get to Canada but one generation makes the entire return trip and overwinters.
In winter they migrate south towards florida and mexico. In the winter they cluster together to conserve heat
What is an ecosystem/how does it work
ecosystems are the processes of our home.
Energy flows through ecosystems from the sun and eventually becomes heat or entropy.
Elements cycle around ecosystems changing forms and are conserved.
Most common elements of life
CHONPS -
78% of the atmosphere is nitrogen.
Animal waste is high in it.
It is important for plant systems.
FERTILIZER - nitrogen, phosphorous,
Carbon
C02 has increased due to release of carbon from ancient times via fossil fuels, fossil fuels production and industrial processes. It is removed by plants taking it in through photosynthesis
Decomposers
Certain insects are instrumental in the breakdown of dead plants, animals and animal wastes - they decompose organisms and fossil fuels
ex: termites, maggots, dung beetles
carbon dioxide and methane
they are both greenhouse gasses - when in the atmosphere they prevent heat from escaping into space.
Dung beetles reduce methane in patties my tunneling through the dung and laying their eggs
biotic vs abiotic
biotic - living - Predators, prey, mates, disease, competition, food, mutualisms, etc. etc.
abiotic - weather, geology, CHONPS, heat, sunlight, temp, etc
fitness
being fit for the situation and successful at what you do
selection
Traits of the most FIT individuals become more populous in the gene pool (allele frequency changes)
3 types of selection
Artificial selection occurs when people decide what genes are worthy
1. Stabilizing Selection - Fitness means being average ex) birthweight in pounds
2. Disruptive Selection: Fitness means being "freaks" of each extreme - can lead to the formation of new
Competitive exclusion principle:
When organisms compete one will win and one will lose. Fitness depends on either:
Outcompeting
Adapting to lessen competition
Types of competition
Intraspecific: Members of the same species or even siblings
Interspecific: Different species that require same resources
Organisms that are competing are wasting energy that could be used for other life sustaining functions that increase fitness.
If you d
Resource partitioning:
dividing up resources so that competition is lessened.
Niche
A specific role that an organism plays in their environment - Is formed by competition
over resources causing adaptation
to form the niche
ex) Eating only milkweed (resource partitioning)
Burying dung
Looking like bird poop
Being freeze tolerant
Having fl
Generalist strategy
Being able to conquer a wide range of tasks or receive input from many different resources.
Specialist strategy
Being able to conquer specific tasks efficiently or specializing in particular resource acquisition
Just because the niche of a specialist may be smaller it doesn't make it less important!
If the niches overlap...
the generalist often outcompetes the specialist
Symbiosis
Interaction between two different species living in close physical association
3 types of symbiosis
commensalism: + , 0
parasitism: + , -
mutualism: + , +
Mutualism relationship story
Ants and acacia trees -
the ants protect the acacia tree, if any vines try to steal the trees light the ants eat at the vines until they fall to the ground, they also sting any animals that try to eat the tree. In exchange, the tree gives the ants everyth
Trophic levels of the food chain
producer, primary consumer, secondary consumer, tertiary consumer. after 3 or 4 conversions not much energy is left
Predation
Predation is hard enough. A more volatile market. Huge amounts of energy is often invested in a failure!
Each attempt can lead to negative consequences even when prey is captured
Only about 10% of insects are predacious!
Features of predators
Often larger, forward facing, widely spaced eyes
raptorial forelimbs
proganthous mouthparts
Predatorial tactics
ambushers, fishing, mimicry
Parasites vs parasitoids
parasites typically do not kill their hosts while parasitoids do!
Bite vs Sting
Bite - Mouthparts
Typically no venom
Although chemicals are often present to break down food
Sting - Stinger
Injects venom
Not used to break down food
Hymenoptera
Evolution of stinger
Sawflies: Cut into plant stems
Woodwasps: Bore into wood
Parasitic wasps: Pierce host tissue
Parts of ovipositor fused into stinger
No longer functions for egg-laying
Types of camouflage
Crypsis - Camouflage that makes the insect difficult to distinguish from the general background
Mimesis - Resembling an object in its environment that is of no interest to the predator
Disruptive coloration - Bold colors that divert attention from the bod
Mimicry
Model - imitated species
Mimic - imitating species
Dupe - who you are tricking
Aposematism
Show colors prominently
Advertise danger
Five Stages of Sociality
Association p- periodic, mating, foraging, overwintering
Sub-social - provide food, brief care for offspring
Quasi-social - unrelated individuals live together
Semi-social - related individuals together, help raise
Eusocial - 1) share a common nest site
2
Termites are in what order?
Blattodea
Type of ant and how its colony survies story
Leaf cutter ant colony - this colony has an extremely intricate and complex tunnel system underground which was created collectively by the ant colony. This colony has created tunnels that allow the fastest routes. It almost looked like an architect desig
Social Insects - Wasps
Unknown number of wasp species, but LOTS!
Most are parasitoids!
Some are free-living species
Most of these are solitary (e.g., mud-dauber)
Only ~700 are social or semi-social
Hornets, yellow jackets: eusocial
Bumble Bees and the British Empire
Darwin wrote on bees and clover
British army kept Britain's supremacy worldwide
Cattle were needed to feed army
Clover was needed to feed cattle
Bees pollinated clover
Mice fed on bee nests
Cats controlled mice
Spinsters were the keepers of cats
Thomas Hu
Stridulation
The scraper and the file are the 2 parts used to make these noises.
Used in two basic ways:
Sexual attraction (i.e. singing)
Warning/defense (=aposematism)
pheromones
chemicals convey information to members of the same species. Most pheromones travel slowly, fade slowly; are effective over long range.
Often combination -- long-range gets the receiver close, short-range confirms info
Alarm pheromone
close-range, high MW, elicits specific behaviors (e.g., fire ant alarm signals stinging, aphids move away)
Sex pheromone
produced by one sex (mostly female), responded to by the other