Adams Insect Bio Exam 3

What is pollination?

Transfer of pollen from the

anther to the stigma

What is self-pollination?

Have both male and female parts

• Ex. tomatoes

What is cross pollination?

Others need pollen from a separate

individual

(cross pollination)

• Ex. apples

How can crop yield increase?

animal pollination ex. bees increase soybean by 20%

Percent of crops that increase from insect pollination

84%

What is incomplete pollination?

causes uneven fruit shape

• Apparent in fruits with multiple

seeds

Percent of pollinators that are insects

99%

Clade of Bees

monophyletic

What pollination do apples need?

cross pollination

Oligolectic Pollinators

- specific

- prefer pollen from single family or genus

-unique adaptations for pollination

ex. squash bees

Bee nutrition

nectar = carbs

pollen = protein

Buzz pollination (sonication)

- thorax vibration releses pollen from antlers ( bumblebees)

Bees life cycle

- Queens diapause in winter

- emerge following spring

Morphological adaptations in Bumblebee

- pollen baskets/corbicula on tibia of hind legs

- wet pollen with nectar to make it sticky

Bumblebee fuzzy body

pollen sticks to hairs and provides insulation

Climate change in bees

may move to cooler climates

Toxic nectar

Plants may be affected from environment w pesticides and can hurt bees

Symbiosis

relationships between plants, insects, fungi, bacteria

Antagonist symbiosis

one species benefits and one doesnt

phytophagous

feeding in plants

insect mouthparts

labrum, mandible, maxillae, labium

Mouthpart of Hemiptera

piercing and sucking

plant fluids: xylem and phloem

Stylet?

formed by mandibles and maxillae which is sheathed within labium

Phloem sap

high in sugar

Adaptation to dilute diet

-filter chamber

-part of gut looped back on itself as countercurrent exchanger (nutrients seperated from water and sugar)

Lepidopteran larvae as pests

worst chewing agricultrual pests

Hempiteran whiteflies as pests

can vector over 80 viruses

Integratyed pest management (IPM)

science-based environmentally sensitive approach to pest management

Coevolution

2+ species reciprocally impact each others evolutionary trajectory

Plant physical defenses against herbivory

- thorns/spines

- Trichomes

Plant chemical defenses against herbivory

-secondary metabollites (almonds produced cyanide)

- Herbivore induced plant volatiles (HIPVs)

What do HIPVs do?

attract natural enemies of herbivores to kill them

Ways insects overcome plant defenses

-some have detoxification enzymes in gut

-behavioral adaptations to avoid defenses

Monarchs and milkweeds

monarch caterpillars consume and store toxic cardiac glycosides from milkweed plants. Monarchs have mutations in pump making them insensitive to these compounds.

Caterpillars and macaranga plants

have ability to walk over trichomes without injury

Tobacco cutworm and tobacco plant

-Feed on tobacco plants

- have cytochrome p450 enzyme in gut to detoxify nicotine

Insecticide resistance

insects evolve to become less responsive to insecticides

Insectivorous plants

plants specialized to eat insects (venus flytrap)

Insectivorous plants: attraction and capture

-use nectar, scent, color to attract

-leaves adapted to trap

-snap traps, sticky traps, pitfall traps

Bladderwort

-horizontal stems containing "bladders"

-bladders use vacuum to trap

Facultative bacterial symbionts

-transmission via bite

- broader array of effects, ranging from manipulation of reproduction

Wolbachia

most common intracellular bacteria, common reproductive parasite

Wolbachia in control programs

male killing: males killed in larval development

Feminization: males develop as females or infertile

parthenogenesis: females can reproduce without males

Obligate bacterial symbioants

-necessary for survival of insects

Blattodea

cockroaches and termites, termites (before were treated as isoptera)

How many cockroaches are pests?

4

Do cockroaches vector disease?

Do not vector disease but linked to allergic reactions (asthma), passively transport pathogens

Cockroach survival

can survive without food for up to

Lifestyle of cockroaches

omnivorous - feed on anything

Blattodea: social behavior

-gregarious/inclined to aggregate

-pheromones influence behaviors

-german cockroaches leave fecal trails to guide food sources

Blattodea: termites

-exclusively eusocial

-cryptocercus: wood dwelling

Termite ecology

-feeding ecology determined by gut fauna

lower termites

feed on wood, rely on symbionts to digest cellulose

Higher termites

-lost characteristic symbionts

-developed compartmentalized gut

crytpocercus

a genus of cockroaches: feed on wood

Diversity of Blattodea social behavior

-share closer phylogenetic relation to termites than other roaches

-eusocial and monophyletic lineage

Fungiculture

occurs when insects have evolved to farm fungus

Leaf Cutting Ants

-take leaves back to feed fungus colonies they farm

-high culture - fungi fully domesticated by ants

Termitomyces

known as termite mushroom - house mushroom and mushroom provides food

Fungal spores

-spores enter body and propagate - kill insects

-interaction where manipulation of behavior causes insect to behave for success of fungus

Entomopathogenic fungus

do not require ingestion but attack cuticle by penetration of exoskeleton

Zombie ants

cordyceps fungus known as zombie ant fungus - targets carpenter ants

controls them

Decomposers

breaks down dead or decaying material

Detritivores

obtain nutrients through consumption of decomposing plants and animals

Insect decomposers

feed on dead or rotten animals or plants

Excrement

manure fly and dung beetles lay eggs on excrement and larvae feed on organic matter

Dung beetle

-prefer herbivore manure

-use olfactory cues, then roll into chamber

Dung beetles and Milky way

-navigation at night

-use polarized light and maintain straight trajectory in absence of moon

-use strips of stars

Necrophagy

feeding behavior on carrion of another organism it didn't kill

Diptera: Brachycera

feed on soft or liquid food

Diptera morphology

-large compound eyes, varied mouthparts

-flies associated with decomposing matter have sponging mouthparts

Brachycera: Larvae

-legless, Maggots

Larva in medicine

maggot debridement therapy - maggots remove necrotic tissue

Myasis

infestation of fly species in living flesh

Screw worms

infest soft tissue, burrow deeper when disturbed

Necrophagous insects

-decomposer insects

-eggs laid on food source

-adults eek site of egg laying on dead flesh

Forensic entomology

The application of the study of insects and arthropods to legal issues.

Medico legal forensic entomology

- related to insects gathered at scene of murder, rape, suicide

-estimate time between death and corpse discovery

postmortem interval or time of colonization (PMI)

interval between death and corpse discovery

What does a forensic entamologist want to know?

-species of insect at crime scene

-succession: pattern of insect colonization

Murder investigations

-deals with specific insects arriving at body to lay eggs

-asses location

-can determine time of colonization

Parasitism symbiotic relationship

one organism lives in another, one benefits/one harmed

Ectoparasites

fleas, lice, ticks

Ant mimicry

visual or non visual, allows them to live unharmed

lycaenid butterflies

mimic brood and alarm pheromones

Brood parasite

deceive into caring the mimic as they would own young

Cuckoo Bees

-lack pollen collecting structures

-enter nest of pollen-collectinng species

-larva hatch and kill host larva

-kleptoparasite lays eggs and sometimes kills queen

kleptoparasitism

parasitism that involves theft, steal food and resources

Faculatative parasitism

does not rely on any host for completion of life cycle

Emery's Rule

trend of social parasites to be closely related to host

Obligate parasites

need host to survive

Pscodea

lice: ectoparasites

flat body allows easy movement

Phoresy

using another organism to travel

Siphonaptera: Fleas

-obligate parasite of mammals/birds that feed on blood

-live in host fur and skin

Fleas morphology

-mouthpart adapted into piercing stylet

- hind legs for jumping

- laterally flattened

-pronotal combs - keep from being removed

Flea habitats

obligate ectoparasite as adults only, eggs laid on host and fall into environment

Flea ecology

-can extend pupal stage during adverse conditions

-vibration, CO2, and heat trigger flea to emerge

Endoparasites

bot fly (oestridae) infest warm blooded animals

Livestock pests: spines

burrow into skin of host

Microparasite

mostly hematophagic: blood feeding

ex. mosquitoes