bsci 337 exam 2

generalist food preferences can change to maintain a balanced diet

response of chemoreceptors in grasshopper maxillary palp sensilla after access to a particular diet (high protein or high carbohydrate) for four hours

miners: morphology matches feeding

phloem and xylem feeding: morphology matches feeding

what are the facts of gut symbionts

-phloem and (especially) poor xylem fluid nutrient

--bacterial symbionts synthesis amino acids needed by their host

-diverse insect groups have both obligate and facultative bacterial in gut

-wood eaters: termites and wood roaches, microorganisms in hindgut fermentation chamber help break down cellulose

ant shepherds

ants storing food

insect agriculture

some ants farm fungi as food

some termites farm fungi as food to break down lignin and cellulose in wood to form can digest

ambush predators examples

diptera:vermileonidae

neuroptera: myrmeleontidae

mantodea (mantids)

phymatidae (ambush bugs)

what is aggressive mimicry

deceiving w false signal to exploit recipient

aggressive mimicry examples

- firefly femmes fatales

-australian katydid (tettigoniidae) imitating clicking response of female cicadas to male cicada calls

mass attack examples

army ants: swarm raiding

driver ants

most dangerous animal in world

mosquitos (blood feeding evolved independently numerous times within diptera)

What order has blood feeders?

Diptera

Definition and example of primary defense

Def: Prevent detection or attack BEFORE the predator initiates

- hiding

- crypsis

- avoid being targets

- mimicry

- aposematism

goal of primary defense

avoid detection

secondary defense definition and examples

definiton: increases survival after a predator has approached

- startling

-resisting/fighting

- fake death (thanatosis)

- spines, sting, toxin, physical/chemical deterrents

- associate with the protector

- escape

goal of secondary defense

increase chance of survival

hiding examples

bagworm case - lepidoptera:psychidae

cases - trichoptera

camouflage & crypsis/masquerade (visual, chemical)

leaf insect: phasmids

Exerma beetle: coleoptera

crypsis vs masquerade

crypsis: blending with background

masquerade: resembling an object

what is crypsis?

making yourself blend in with background

what orders utilize crypsis?

-phasmida

-orthoptera

What is masquerade?

resembling as something of disinterest

mimicry

wasp & bee mimics examples

lepidoptera (clearwing moths)

diptera (hoverflies)

neuroptera

orthoptera: katydids

mantodea

mimicry

ant mimics examples

salticidae

tettigoniidae

miridae

jumping spiders

mimicry

mimics of distasteful models

what is aposematism?

warning signal

types of aposematism

primary or secondary

visual, chemical or acoustic

aposematic firefly flashing

-sexual signal, also deter predators and attract others

-hypothesis: lampyrid flashing effective aposematic signal using spider predators, palatable crickets, fireflies of unpalatable non luminescent species

does sudden flashing itself deter jumping spiders?

- (palatable) cricket next to LED turned off vs suddenly flashing were attacked qually: no startle behavior

does flashing light (vs no or steady light) attract or deter spiders attacking palatable prey?

- spiders more likely attack cricket next flashing LED vs LED turned off or steadily glowing

does flashing light facilitate avoidance of unpalatable prey w experience?

- yes (see graph)

startling examples

hemiptera: fulgoridae: spotted lantern fly

lepidoptera

feigning death (thanatosis) examples

coleoptera: blue death feigning beetle

hemiptera: pentatomidae: stink bug

armor, weapons, bites, and pinches examples

rough & tumble

Zopheridae: Ironclad beetle

nolidae: uraba lugens

- stacked head capsules from multiple molts

hornworm: hissing, trashing, green goo

chemical (synthesized, sequestered), stings examples

sequestered defensive chemicals: insects on milkweed

lygaeidae

nymphalidae

chrysomelidae > batesian mimic (harmless species evolves resemble dangerous or unpalatable species, tricking predators)

synthesized defensive chemicals

coleoptera: carabidae: bombardier beetle

sting pain index

collective defense of social insect colony

blattodea: "exploding" termites

-defend against ant invaders

hymenoptera

-ants protect aphids against lacewing larvae and wasps

escape examples

hymenoptera

- trapjaw ants mandibles

- ant knows slope and will roll away

what is chemoreception?

detection of chemicals in both:

- gaseous state (olfaction)

--olfactory receptor numerous microscopic pores permit entry of chemicals

-on surfaces or in solution (contact chemoreception)

-- contact chemoreceptor just single pore at tip

chemoreceptors location

olfactory sensilla mainly on antennae and maxillary & labial pala

- other body parts > genitalia

contact over whole body, especially on mouthparts (labrum, maxillae, labium)

- often on legs and antennae

- ovipositors some female insects

-none on mandibles

what are semiochemicals?

chemicals produce by individuals affect behavior of other individuals (of same or different species)

_________ influence behavior conspecifics

pheromones influence behavior conspecifics (member of the same species)

___ influence behavior of heterospecifics

allomones, kairomones, and synomones influence behavior of heterospecifics

allomones are what?

benefit signaler

kairomones are what type of receiver?

benefit receiver but not signaler

synomones relation with signaler and receiver?

benefit both signaler and receiver

Can the same chemical signal fall into more than one category?

- same signal could fall into more then one category depending on recipient and context

- example: moth sends out chemical (pheromones) for mate, predators recognizes chemical & attacks (kairomones)

What does pattern perception for vision require?

optics & basic neurophysiological but also cognitive processing

What is a compound eye composed of (units)?

composed of multiple similar units > ommatidia

- each has optical light gathering portion & sensory portion transforms light into electrical energy

well compound eyes = _____ field of view

wide field of view

Do flying and jumping insects generally have good distance perception?

Yes, excellent

What color receptors do pterygote insect eyes have ancestrally?

ultraviolet, blue, and green receptors

-different set combine w different types ommatidia > heterogeneously across eye

What orders have more than three color receptor ranges?

Lepidoptera, Odonata and possibly some Hymenoptera and Coleoptera

Knockout of bab gene results in ___

UV Iridescence

vision

oceeli

adult insects (especially flying), immatures of many hemimetabolous possess set up to 3 dorsal ocelli

consist closely packed cluster photoreceptor cells w single lens

direct light

in some, important in visual detection of motion

vision

stemmata

larvae holometabolous lack compound & ocelli

most bear single-lens eye on sides of head (stemmata)

- one to tens of thous.

-most common, 6 stemmata on each side head (larval lep.)

mechanoreception

basis of both touch and hearing

- sensing vibrations carried by air,water and solid substrates

- many are proprioreceptors > monitoring position of body parts

- most large hairs on body

-mant contact chemoreceptors have this function

chordotonal organs definition and examples of locations?

subcuticular mechanoreceptors often function as joint propriorecptors or hearing organs

johnston's organ found in antennae of all adult entognath

- chordotonal organ in antennal pedicel has distal insertion between pedicel & flagellum

- help insect sense air or water flow orientation relative to gravity, even near-field sounds

tympanal organs subcuticular receptors specialized for sound reception have evolved multiple times & known from 7 orders

origin of hearing in insects?

to facilitate the detection and avoidance of predators

other use of hearing in insects?

can also be used for prey detection (mainly attack males)

- Some blood-sucking frog-biting midges that hone in on the calls of frogs

- Parasitoid flies that track singing Orthoptera or cicadas

substrate-bourne vibrations

widespread among insects

can be on soil or any solid material

Cataglyphis Desert Ants rely heavily on _______ to find their way back to their nest?

path integration

supplemented by visual cues

Path integration

calculating the current location relative to home (and hence the direct homeward trajectory) by integrating distance and directional information acquired during the outbound trip

Cataglyphis desert ants Experiment

leg lengths normal during outbound journey but manipulated during homebound journey:

- stilted ants counted correct number steps but traveled to far

- stubbed ants ended up at shorter distance

ants tested after reemerging from nest after previous manipulation, manipulated legs during outbound and inbound:

- stilited and studded ants traveled correct distance

tympanal organ are what?

area of thin cuticle, typically has air ac behind it, allowing membrane vibrate freely

sound waves provide info. about intensity and frequency of acoustic signal

tympanal organ location

forelegs of crickets and katydids

thorax of some true bugs and flies

abdomen of cicadas, grasshoppers, and some moths and beetles

path integration in dung beetles

most remain at pile, burying themselves within or beneath

others form ball and roll it away

-Scarabaeous lamarki maintain straight path away > compass on sun position and wind direction

- others use celestial cues > position of sun and moon, patterns of light across sky, light polarization

small number leave to dig burrow, make multiple trips back to pile transfer dung to burrow

Scarabaeus galenus (Dung Beetle) experiment

beetles master route over multiple foraging trips, then displaced before returning to burrow

displace beetles before returning to borrow as if not displaced ignored landmarks, replying on path integration

- ignore visual cues

honey bee navigation

waggle dance > how honey bees share foraging information with colony

figure 8

upward vertical run > directly toward sun

angular deviation to left or right of vertical > bearing left or right of sun horizontal position in sky

1 sec. increase = 1.00 km

adjusted as sun moves

bee didn't see waggle dance in early foraging > less sufficient w dance

honey bee judging distance

flew at great height between tall buildings, underestimated distance traveled

- less optic flow

-images of ground move more slowly across retina

test of optic flow hypothesis

flew route w portion through narrow experimental tunnel w complex visual texture at close distance

- overestimated distance traveled

pattern in tunnel consisted of stripes parallel to flight, optic flow was reduced

-underestimated distance traveled

other honey bee cues

forage

-olfactory cues and past experience

navigation fine tuned by visual land markers

communication

narrow sense: "true communication"

-signal sender and recipient benefit

broader sense

- signal benefit to sender only or recipient only

signal: evolution > transmit specific message from emitter to intended receiver

cue: info, to receiver but not shaped by natural selection for purpose

-may be exploited by receiver to detriment of emitter

finding mate

sexual signals shaped by natural selection for connecting w mate

- chemical

-acoustic signals

-visual

-tactile

example of sexual signals

synchronous fireflies

cricket singing

cicada calling

jerusalem cricket drumming

link between signal and preference

Heliconius cydno & H. melpomene

close physical linkage between at least some loci determining mate choice-associated traits and preferences

- wing pattern important in mate choice

- 3 genetic loci identified > difference in wing pattern preference btwn males of two spp.

-- one loci close major wing patterning gene > optix

link between signal and preference

Drosophila melanogaster

gene identified that pleiotropically involved with both synthesis and discrimination of cuticular sex pheromone

acoustic signals & preferences

Hawaiian Laupala crickets

- hybrids through interspecific crosses allowed quantitative genetic analysis of genetic arch. underlying variation > both male song and female preference

-ex. : co-localized song & preference quan. trait

-others, strong genetic covariance but no evidence strong physical linkage btwn song and pref. loci

phenotypic plasticity in signaling

Gryllus rubens

-seasonal difference in fall and spring song pulse rate

-- result of difference ambient temp. during juv. and adult development

- fall females preferred song w fall-like parameters

-spring females preferred songs w spring-like parameters

signals: queen bee

queen signals (mostly chemical)

-suppress worker reproduction

signals: trail pheromones

trail pheromones in ants and termites (chemical)

-reinforced recruited foragers returning to nest w food, dissipates as fewer returning w food

- trails pheromone partly learned than innate

signals: alarm pheromones

in social insects > aphids

- on species & context, may trigger dispersal or aggression

4 Types of Mimicry and Aposematism

1. batesian (harmless to minic dangerous model so mimic only benefits)

2. mullerian (2+ species share warning pattern so less predation from same predators)

3. aposematism (warning signal for defense)

4. wasp/bee mimics (seem harmless but predators know to avoid)

Types of chemical defenses

1. sequestered chemicals: insects on milkweed to get toxins

2. syntheiszed chemi: bombardier beetles that have hydroquinones and H202 in reaction chambers for a hot spray

3. stings: hymenoptera with the pain indext

What are semiochemicals

chemicals produced by individuals that affect other’s behavior

4 types of chemoreception

1. pheromones: affect conspecifics (same species) eg sex, train, alarm phermones

2. allomones: benefit signaler, not reciever (kairomone via defense secretions exploited by predator)

3. kairmones: benefit receiver, not signaler (predator detects prey trail)
   synomones: benefit receiver and signaler (pollinators to flowers)

2 types of insect receptors for chemorecpetion

1. olifactor senses: multiple pores on antennae and palps

2. contact chemoreceptors: single pore on mouth, leg, ovipostioor with NO recpetors on manidbles

the 3 types of eyes

1. compound eyes: ommatidia with optical portion for wide field of view with excellent distnace perception

2. ocelli: 3 dorsal ocelli inflying insets and hemimetabolous immatures; single len over cluster of photoreceptors; detect light and motion

3. stemmata: HOLOMETABOLOUS LARVAE only