Lecture 5

Question 1

what are the physiological constraints of an insect?

Answer 1

size -rate of heat gain or loss

respiration - water loss

Question 2

what is the relationship with body size & heat loss?

Answer 2

body size incres = lose heat more quickly

Question 3

how do insects respond to the cold?

Answer 3

temp regulation - endothermic or ectothermic regulation

temp compensation - cold tolerance

Question 4

what is an ex of endothermic regulation?

Answer 4

honey bees maintain warm hive throughout the winter

Question 5

what are some strategies of ectothermic regulation?

Answer 5

microhabitat

colouration

migration

Question 6

how is shivering accomplished in insects? & Exs? (3)

Answer 6

uncoupling wings - vibrate bodies (ex: bumble bees)

opposing muscles - muscles work at the same time (ex: moths)

insulation - fur decres the cooling effect, incres wind velocity = incres rate of temp loss (ex: winter moth)

Question 7

basking

Answer 7

allow heat & sun to warm body

Question 8

what are the 2 forms of basking?

Answer 8

lateral basking (ex: cabbage white butterfly)

dorsal basking

Question 9

is shivering an endothermic or ectothermic response to the cold?

Answer 9

endothermic

Question 10

is basking an endothermic or ectothermic response to the cold?

Answer 10

ectothermic

Question 11

explain the colour change & thermoregulation process. Who does this?

Answer 11

chromatophores are affected by temp (cells change pigemnt levels in response to cold)

when it gets colder, the cells create darker pigment to absorb more light & heat

green darner butterfly

Question 12

describe the gregarious (aggregation) behaviour of the eastern tent catepillar

Answer 12

create silk tents for protection & bask as a community to maintain temp

increasing their volume to decres SA

Lower SA:V ration to conserve heat

enables them to have a higher metabolism process food faster

Question 13

describe the gregarious (aggregation) behaviour of the honey bee

Answer 13

aggregate into a hive

packs in the hives are constantly moving & rotating creating heat

consume honey enabling them to conserve body heat

Question 14

what are 4 insects that can withstand cold temps?

Answer 14

snow scorpion

ground beetle

snow flea

golden rod gall fly

Question 15

what insects survives the coldest temps? & what temp?

Answer 15

golden rod gall fly at -87C

Question 16

how do ground beetles withstand cold temps?

Answer 16

cryoprotectants (glycerol) to prevent freezing

Question 17

non-freezing injury

Answer 17

cold shock - membrane failure, enzyme or io imbalance

damage/death

Question 18

freezing injury

Answer 18

mechanical damage

recrystallization

osmotic shock

Question 19

freeze tolerance

Answer 19

control where freezing occurs

extracellular ice can be tolerated

use ice nucleators initiate ice formation at warmer temps to prevent the insect from freezing suddenly at the super cooling point

enables the insect to adjust more slowly to osmotic pressures

build up their store of compounds that reduce the level of ice formation

Question 20

ice nucleators

Answer 20

compounds that induce ice formation

Question 21

what are the ice nucleator compounds?

Answer 21

food

PROs

ice crystals

calcium phosphate

uric acid

Question 22

super cooling point

Answer 22

temp point where the insect freezes

Question 23

freeze avoidance

Answer 23

prevent freezing to avoid ice damage

Question 24

what are the strategies of freeze avoidance?

Answer 24

cryoprotectants - lower super cooling point to prevent freezing

antifreeze PROs - bind to ice crystals

evacuate gut with bacterial freeze

Question 25

what are the cryoprotectant compounds? (3)

Answer 25

glycerol ethylene glycol trehalose (sugar)

Question 26

midge larvae are active at what temp?

Answer 26

43 C

Question 27

cryptobiosis-dehydrate

Answer 27

cytobiosis: ability to survive a state without metabolism dehydrate - stops metabolism in high temps

Question 28

shield & ex

Answer 28

wax emerges from the insect's pores, layer where air is trapped ex: Nambi Desert Tenebriondi Beetle

Question 29

describe fog catchers in the desert

Answer 29

drink dew to increase their moisture 1. build a ridge in the sand to catch dew 2. drink dew in sand have bumps & valleys that collect water that runs down their back & into the moth

Question 30

describe the bumps on the fog catchers in the desert

Answer 30

hydrophilic - no wax

Question 31

describe the valleys on the fog catchers in the desert

Answer 31

hydrophobic - contain wax

Question 32

describe convective cooling in a dragonfly

Answer 32

obelisking - stick abdomen in the air to reduce direct contact with the sun

Question 33

stilting & ex

Answer 33

bodies are off the ground ex: tiger beetles

Question 34

convection run & ex

Answer 34

runs at 1 m/s ex: desert tenebrionid

Question 35

evaporative cooling (3)

Answer 35

from the nectar they drink cool hives wings used as fans

Question 36

panting & ex

Answer 36

spiracles move air through the body ex: locust

Question 37

sweat & ex

Answer 37

pores release moisture that evaporates ex: mosquitos

Question 38

cryptonephridial complex

Answer 38

absorb water through their anus

Question 39

what are the 3 main ways that insects survive adverse conditions?

Answer 39

cryoprotectants behavioural traits exchange of air temp around them