Insects 2.5

rhodopsins

molecules that detect light

how many photoreceptor cells

7-9

what is the breakdown of photoreceptors

2 green, 2 blue, 2 UV, 2 any of above (sometimes red)

what colors do some lepidoptera and odonata see

5 different colors (including red)

polarized light

light that shines from the sky or reflects from shiny surfaces, light in different directions of the horizon have different polarity → help to direction

how do insects see direction

pigments are alligned in microvilli of photoreceptors making them sensitive to direction of light

pigment cells

insulate ommatidia from each other to increase resolution of image, increase sensitivity to particular colors

resolution

ability to distinguish between two objects

what determines resolution

density of photoreceptors at light collecting part of eye

what does higher resolution

smaller angle that can be detected

what angular degree can insect eye see

~1 angular degree

sensitivity

ability to see light

more ommatidia

greater resolution

smaller ommatidia

less sensitivity

which part of the eye has better resoltuon

in front of eye

compound eye

motion detector

what are the rhodopsins

opsin and retinal

why are each ommatidia independent

dont want to see 2 of the same thing, changes indicate movement

honeybee vision

can distinguish between groups, cannot distinguish within groups

ocelli

detect horizon (whats up whats down), adult insects typically have 3

stemmata

only visual organs on lepidoptera larvae, light sensitive

dermal light receptors

drosophila have light receptors containing rhodopsins in their dermis that allows them to avoid light

genital photoreceptors

in lepidoptera

electroantennagram

used to look at action potentials on antenna hairs

how do they detect odors

receptor recognizes smell, binds, opens, sodium comes in, makes more psoitivie causing action potential,

what are the subunits of an odorant receptor

2 orco (NEED THIS TO SMELL ANYTHING), 2 odorant

where is olfactory information processed

antennal lobes in brain

how many odorant receptros do archeoagnatha have

5

how many odorant receptros do zygentoma have

50

how many odorant receptros do mosquiots have

80

how many odorant receptros do ants have

500

how do mosquitoes find us long range

heat, co2, highly volatile body odors

how do mosquitoes find us short range

less volatile body odors, taste of skin, taste of blood

where are heat receptors on msoquitos

antenna

wherre are odorant receptors on mosquitos

labial palps +antenna

where are taste receptors on mosquitos

feet + proboscis

How does deet work

blocks smell receptors and tastes bad

do citronella candles work

no mosquitoes are crepuscular, meaning they bite during sunset, by the time people think the candle is working it is actually just night and mosquiots no longer biting

what do flies taste with

feet

what are practical applications of olfaction research

good to see if insects are there, pheremone traps for pantry moth and clothes moth, not good for control

do female crickets sing

no crickets are hemimetabolous and only adult males sing

where are ears on tettigonidae and why

ears far apart on legs, can be used to tell direction and if bats are around

why are cicadas so loud

indirect wing muscles power a membrane to vibrate, males deaf to own nois

how do cicadas make noise

abdomen filled with air with amplifies sound, produced by longitudional muscle

what happens when a female cicada likes the sound of a male

she clicks her wings to make a sound that attracts males

what happens when cicadas are infected with fungus

turns males into sex zombies (more sex with more people leads to better spread of fungus), makes male click like females which attracts males and then they mate with them

what do male msoquito antenna look like

they have bushy antennae (interested in finding people bc thats wherre females air) helps to vibrate when at frequency of female wing beat, johnsosn organ to hear

what frequency can moths hear

22000-75000 Hz

why can they hear so good

to avoid bats

why do luna moths have tails

the tails are audible to bats, they eat the tail and the moth escapes

why are moths fuzzy

sound is muffled, does not bounce back

what is the subgenual organ

located in the wasps tibia nad is sensitive to vibrations, use it to drum on wood to find hollow space in wood with grubs

how do honeybees find other bees w/ flowers

waggle dance, shows where flowers are, it is dark so the bees send vibrations through honeycomb, sgo on honeycomb, strength of dance is distance, angle

hawaii crickets

a parasitoid fly that lays its eggs in crickets almost wiped out crickets, but the crickets evolved a different wing that chirped silently, some still chirp to attract females

what are fly ears being investigated for

hearing aids - directional hearing

crab lice

like pubic hair, different specias from head and body lice

head lice characteristics

cannot survive more than a day away from host, feed every 3-4 hours, lay ~5 eggs per day, live 27 days as adult, not vectors, glue nits to hair

what is the only completely parasticic order

phthiraptera

what is morphologically different between head and body lice

head lice have a shorter and wider head and prominent abdominal indentations

body lice characteristics

lays 600 eggs in lifetime, explosive population expansion, can survive on clothing for a few days, vector of bacterial pathogens

epidemic typhus

symptoms similar to rocky mountain spotted fever, found in places of inhumane conditions, bacteria live inside cells in blood vessels

what is the genetic difference between head and body lice

have all of hte same genes, 14 genes expressed at different levels

how do head lice become body lice

when population gets very dence, they make epigenetic modifications in the genes of the eggs they lay

how does body lice act as a disease vector

bacteria enter the human from louse feces when the bite area is scratched or louse is smashed

why are only the body lice vectors

physiology promotes explosive population growht, fever causes lice to abandon host spreading the pathogen, conditions that favor body lice also contribute to poor immune response

characteristics of gregarious locusts

attracted to each other, breed rapidly, migrate in swarms, cannibals and herbivorous, swarm, larger calyx and mushroom body lobes

why do gregarious locusts swarm

safety in numbers, easy to find a mate

characteristics of solitary grasshoppers

avoid each other, breed rapidly, dont migrate, vegan

what causes solitary grasshoppers to become gregarious locusts

when population grows and the solitary start bumping into each other they start to produce seratonin and on next molt become gregarious and the population keeps growing

what causes gregarious locusts to become solitary grasshoppers

conditions are bad and population shrinks, no longer in contact, produce seratoning and on next molt are solitary (generally the switch is passed between generation to generation)

why do monarch butterflies migrate

escape the cold

what is a monarch life cycle

early summer: females mate and lay eggs right away, baby caterpillars eat the hairs on milkweed leaves, 2 weeks later caterpillar, chrysallis 2 weeks,

late summers: adults wont reproduce for 9 months

november-march in mexico

march - april: journey nourth

what is different about monarchs in late summer

reproductive diapuase

what is the cue for reproductive diapuase

shorter days, old milkweed, differences in juvinile hormone

tiger mosquitoes

aedes albopictus, agressive bite during the day

when were tiger mosquiotes introduced to the us

1985

what are aedes albopictus vectros of

zika, dengue, chikungunya

how do aedes albopictus survive cold iwnter

diapausing larvae inside a waterproof shell

how do aedes albopictus sense that winter is coming

day length as well as temperature and diet, short day diapuse, long day no diapause

critical photoperiod

length of day that leads to 50% diapuase eggs

what is the critical photoperiod in allentown

august 28 ~13 hours

why do they not diapuse near equator

no critical phoperiod, 9 month break from reproducing if you dont have to is a bad idea

how did they find where houston mosquitoes come from

looked at if the eggs could diapause and if eggs could survive