insect communication Flashcards
What is communication?
a signal produced by one individual that causes a change in behavior of another conspecific individual
What are the MAJOR modes of communication in insects?
- chemicals (pheromones)
- light
- sound
What is the range, rate of change, move around obstacles and energetic cost of visual signals in insects?
range: medium
rate of change: fast
move around obstacles: poor
energetic cost: low
What is the range, rate of change, move around obstacles and energetic cost of acoustical signals in insects?
range: long
rate of change: fast
move around obstacles: good
energetic cost: high
What is the range, rate of change, move around obstacles and energetic cost of tactile signals in insects?
range: short
rate of change: fast
move around obstacles: poor
energetic cost: low
What is the range, rate of change, move around obstacles and energetic cost of chemical signals in insects?
range: long
rate of change: slow
move around obstacles: good
energetic cost: low
What are pheromones?
chemical signals that carry a message between conspecifics
Where are volatile pheromones?
percieved by olfactory sensilla on the antennae (moths, bark beetles and aphids)
What are non-volatile pheromones?
deposited on a surface and percieved by gustatory sensilla on antennae or tarsi (cheery fruit flies)
What is a major benefit of using pheromones?
extreme species specificity although often through multicomponent blends
What are pheromones in danaid butterflies?
modified pyrrolizidine alkaloids obtained from plants
Where are pheromones often synthesized?
in exocrine glands
What is the synthesis of pheromones regulated by?
PBAN (pheromones biosynthesis activating neurohormone) produced by the subesophageal ganglion
What is a draw back of pheromone use?
they can be intercepted or even secreted by predators
What does the american bolas spider catch through secretion of pheromones?
smoky moth and bristly cutworm
What does the checkerd beetle catch through interception of pheromones?
bark beetle
What are two types of pheromones?
releasers and primers
What do releaser pheromones do?
cause an imediate behavioral response in the receiving individual
What do primer pheromones do?
cause longterm physiological changes in receivers
What are some types of receiver pheromones?
- sex attractants: often released by female - long distance
- aggregation:
- spacing (epideictic)
- alarm
- Trail
What do aggregation pheromones do?
brings many conspecifics together quickly
egL mass attack of bark beetles on trees to overcome resin defenses
What do spacing pheromones do?
evoke behaviors that lead to increased space between individuals
(eg: apple maggot flying oviposition deturrent pheromone)
What does an alarm pheromone do?
stimulates escape or other defensive behaviors
eg: honeybee sting incites nestmates to sting, aphid attacked by predator causes others to flee
What are trail pheromones used for?
insects lay trails to food sources
eg: foraging ants
What are some types of primer pheromones?
- colony pheromones
- gregarization pheromones
What do colony recognition pheromones do?
kin and colony recognition, control of reproduction and kin number, foraging behavior.
- normally produced by the queen and have both releaser and primer effects
- used by social insects
What do gregarization pheromones do?
cause transformations in locusts from the solitary phase to the gregarious phase.
- includes both releaser and primer effects
- produced in feces
What are the practical applications of insect pheromones?
- detection of pests (eg: gypsy moth in bc, beetles stored in grain)
- Population monitoring
- Mating disruption
- mass trapping
- attract and kill
- honeybee queen pheromone
What is an example of population monitoring in regards to pheromones?
codling moths in okanagan orchards. Traps indicate time of adult flights and population size - predicts when eggs will be laid. pest management practices can be timed for optimal efficiency
What is mating distribution in regards to pheromones?
sex pheromones of a species is identified and synthesized in large quantities. the synthetic pheromone is then released in great quantities in farm or orchard so males will be confused and unable to locate females with which to mate
eg: used on codling moth, fireworm and tomato pinkworm
What are some common types of pheromone traps?
- delta trap
- bucket trap
- wing trap
What does mass trapping do?
removes sufficient individuals from a population in order to reduce economic loss
eg: ambrosia beetles around bc sawmills
What is the attract and kill method?
synthetic sex attractant pheromone is mixed with tiny amount of insecticide –> attracts males and kills them
What are two commercial honeybee queen pheromones and what do they do?
- fruit boostTM –> increases fruit yields by increasing bee pollinating activities
- Bee boostTM –> calming effect on bees when they are being shipped which increases their survival rate
What is an insect that uses light production to communicate? how?
fireflies via a flashing organ in their abdomen
- used in mating and courtship
- pattern of flashes in species specific (duration and frequency)
What are three different mechanisms of sound production in insects?
- byproduct of usual activity eg: wingbeat frequency, thoracic vibration of queen honeybee
- impact of body on substrate eg: deathwatch beetles tap walls of their galleries in wood with heads to make ticking sound
- special mechanisms
What are three types of special mechanisms involved in the production of sound in insects?
- frictional mechanisms - strudulation
- vibrating membranes
- air movement
What are frictional mechanisms that produce sound in insects?
- crickets and katydid rub their forewings (tegmina) together. one wing has a scraper while other has a file.
- grasshoppers use row of pegs on hind femur which they scrape against the abdomen
- waterboatmen run forelegs against back of head capsule to produce high frequency chirps that can be transmitted underwater
- mate location/courtship mechanisms
What are vibrating membranes that produce sound in insects?
- cicadas have a tymbal (elastic membrane stretched over a hollow cavity in the 1st and 2nd segments). rapid muscle contractions cause high frequency vibrations that ar amplified by the hollow area. tone regulated by tension
What are air movements that produce sound in insects?
air forced through spiracles causes hissing in coackroach + squeak in june beetle
- defense mechanisms
