Entomology Q4 to Final

What are the four most diverse and important pollinator orders?

hymenoptera, diptera, coleoptera, lepidoptera

When did pollination evolve and what functional guild became the first pollinators?

130-90 MYA

herbivores (antagonistic interactions)

3-4 reasons why insects are effective pollinators

insects have specialized structures to collect and transport pollen

behavioral preferences: specialization reduces competition

flight enables gene flow across wider distances

3+ ways that insects perceive floral signals

flower color (including UV)

electroreception (sensory setae +, pollen -)

Chemosensory: volatile compounds/fragrances

deceit pollination

pollinators attract insects without offering a floral reward

(recall video of flower attracting male by looking like female)

pros and cons of specialization

Pro: reduced competition, small niches, promotes biodiversity

Cons: reduced reliability, increased extinction risk if partner changes distribution/phenology

pros and cons of generalization

Pro: redundancy, abundance of resources

Con: increased competition

(may need to travel further to find food)

exophage

eat the outside of the plant (exo=outer)

Endophage

eat from the inside of the plant

(endo=within)

Folivory

leaf-eating

Most lepidoptera

Most coleoptera adults/larvae

most orthoptera

Granivory

seed eating (and boring)

weevils

sap-suckers

almost all hemiptera

cicadas and allies

scale insects and mealy bugs

aphids

leaf-miners

larvae of diptera, lepidoptera, some hymenoptera, coleoptera

galls

A plant growth formed around eggs and/or larva of parasites on the plant

hymenoptera, diptera, aphids

mechanical plant defenses

(morphological)

trichomes, pubsecence (hair), spines

Leaf thickness, waxes, serrate/spiny leaf margins

qualitative plant defenses

toxins, secondary chemicals

less costly, don't need as much

alkaloids, pyrethrin, terpenoids, nicotine

quantitative plant defenses

digestibility reducers

reduced nutritional uptake, costly

cellulose, lignins, tannins, silica, latex, resins

reciprocal coevolutionary arms race

most mutualisms (pollination) arose from antagonistic interactions between plants and herbivores

- plants keep evolving anti-herbivore defenses

- insects keep evolving ways to get around those defenses

Janzen-Connell hypothesis

probability of seed dispersal decreases as distance from parent plant increases

Major orders of parasitoids

diptera and hymenoptera

koinobiont parasitoids

let host develop until pupation/emergence

usually endoparasitoids

tend towards specialization

idiobiont parasitoids

stop host development

usually ectoparasitoids

tend towards generalization

Superparasitism

one host attacked by multiple parasitoids of the same species

multiparasitism

one host attacked by multiple parasitoid species - can lead to competition within the host body

secondary/hyperparasitism

parasitism of a parasitoid

major strategies to avoid predation

crypsis, minesis, mimicry

crypsis

camouflage - blending into the environment

mimesis

mimicry of a specific object in ecosystem

mimicry

carefully executed evolutionary relationship by mimic with model insect to trick observer

Batesian mimicry

A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.

mullerian mimicry

two or more unpalatable species resemble each other