Lecture 3 Flashcards
How do we quantify insect dominance? (5)
Insect diversity
Numerical dominance
Distribution
Reproduction
Attributes making them successful
____ of all species are insects
53%
____ of described animal species are insects
73%
there are _____ described insect species
1 million
up to ____ of insect species may still be undescribed
95%
1/4 of animal species are ____
beetles
there are ____ species of Rove beetles, a single beetle ____
61,000
family
what family of insects is the most diverse?
rove beetles
estimates of the total number of insect species range b/w _____
1-4 million
at any time, there are an estimated _____ insects alive
10 quintillion
there are _____ insects for each human on the planet
~200 million
there are ____ ants for each human on the planet
~1.6 million
a single swarm of migratory locusts can contain ____ indivs (Africa)
1 billion
in the Brazilian rainforest, there’s ____ times more insect biomass than vertebrate biomass
9
There are at least ____ species of insects in Manitoba
10,000
there is at least ___ species of insect for each vertebrate species in Manitoba
40
what is the only major envr not dominated by insects? & why?
open ocean
the niche is filled by ither Arthropods
how does reproduction contribute to the dominance of insects?
they have a rapid reproductive time & for many insects, it is exponential
describe the reproduction process for aphids
in the summer, all aphids are females
they clone themselves to reproduce
after 8-9 days of age, the offspring have reached the adult stage & can reproduce themselves
rapid pop growth!!
what is the origin of insect lineages?
400-420 million years ago (before plants, angiosperms & gymnosperms)
near to when terrestrial habitats formed
What are the attributes that contribute to an insect’s success?
long evolutionary history
small size
exoskeleton
flight
reproductive capabilities
how does small size contribute to an insect’s success?
enables them to use a broader range of ecological niches
how does having an exoskeleton contribute to an insect’s success?
water-resistant - enabling them to survive a wide range of envrs
how does flight contribute to an insect’s success?
contributes to diversity b/c insects can use many diff habitats
how do humans utilize insects’ decomposition role in the envr?
for forensic investigations
the role of pollination is important in what type of ecosystems?
agricultural & natural
what percent of wildflowers are pollinated by animals (including insects)?
80%
insects form the base of animal food webs in what type of ecosystems?
terrestrial & freshwater aquatic
insects as herbivores do what?
provide food for higher trophic levels
represent a critical link b/w primary & secondary production
insects are consumed by every vertebrate group except for:
lamprey - parasites of fish
what source of nutrition do insects provide to humans?
fat & PRO
what are the 2 types of insects that naturally control of pests?
predators
&
parasitoids
what are exs of predatory insects
dragonflies - both as juveniles (aquatic) & adults (terrestrial)
robber flies
lady beetles - feed on eggs of insects (including aphids)
parasitoids
lay eggs into or onto insects & the developing larva kills the host inside out
what are exs of parasitoids?
scaphinoitois - feed on snails
wasp
flies
natural enemies
insect predators and/or parasitoids that control pests
what are the natural products insects produce that humans have utilized? (5)
silk
honey
beeswax
dyes
shellac
what countries produce silk
China & East Asia
what type of insects produce silk?
domesticated silkworm moths
how have the silkworm moths changed as a consequence of being used for silk production?
female moths no longer fly - wings have degenerated due to bein kept in captivity
what part of the silkworm moth is used for its silk?
the pupil case from the caterpillar
what insects produce honey?
honey bees
what insects produce beeswax?
honey bees
what type of dye is predominantly made from insects?
red dye
what part of the insect is used for shellac?
insects produce a protective & sticky coating over their bodies which is used
what type of insect is used for shellac glue?
scale insect
why are insects beneficial in research?
small
easy to maintain
high reproductive rates
how are insects used in research?
bioindicators of ecosystem health & envr toxicology
fundamental & applied ecology
models in research on evolution, genetics & physiology
what percent of insect species are considered pests?
1%
what percent of insect species are considered serious pests?
0.1%
insects are considered pests if they:
nuisances of humans, pets or livestock
damage crops, forests or human commodities (feed on things of economic value)
transmit disease to humans, pets, livestock or wildlife (insects as vectors)
