Fbs45 Lect8a Insect Behavior

8/2/2019 Fbs45 Lect8a Insect Behavior

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INSECT BEHAVIOR



BEHAVIOR

= directive action and reaction of anindividual toward the environment for its

survival, reproduction and perpetuationof their kind.

- usually instinctive but sometimes learned





Kinds of Responses

Taxes – directed responses causing theinsect to move toward or away from

the stimulus. (e.g. +/ – phototaxis,hygrotaxis, anemotaxis)

Tropism – directed behavioral responseconsisting of orientation with respect tothe stimulus. (e.g. insect facing thesource of light)



CIRCADIAN RHYTHM

= “biological clock” or the daily activities of

insects following a regular occurrence.

(DIURNAL, NOCTURNAL, CREPUSCULAR)



DORMANCY = state of inactivity of

insects/animals to survive duringperiods of extreme environmentalconditions (AESTIVATION and

HIBERNATION ).QUIESCENCE = a temporary dormancy that

lasts only until favorable conditions

return.



DIAPAUSE = prolonged dormancy that

usually results from an interruption inthe hormonal stimulation of growth in

immature insects or reproduction by

adults as influenced by a set ofenvironmental stimuli.

PHEROMONE = a substance given off by

one individual that causes a specificreaction by other individuals of thesame species (Alarm, Trail, Sex).



Feeding Behavior

• Phytophagous (herbivorous )

• Zoophagous (carnivorous )• Saprophagous (scavengers )

• Detrivores (decomposers )



Phytophagy

• Polyphagy – generalists

•Oligophagy

– feeding on few hosts

• Monophagy – specialists



Phytophagous insects can becategorized as…

• Foliage or leaf feeders (defoliators & leaf miners)

• Wood feeders (stem-, bark-, wood-, twig-,or shoot borers)

• Fruit feeders

• Seed feeders

• Sapsuckers

• Root feeders





Saprophagous insects as…

• Carrion feeder

• Dung feeder (cocrophagy)

- mostly coleopterans and dipterans



Defensive Behavior

• Active means by flying running, jumping, etc.

• Passive means by playing dead or being

motionless• Use of shelters

• Chemical defenses using body secretions



CRYPSIS = type of coloration, structure andbehavior that aids concealment of an

insect/animal. Procrypsis andanticrypsis

CAMOUFLAGE = resemblance to the

background.



MIMICRY = resemblance to other species.

MULLERIAN MIMICRY = the insects advertisegenuine distastefulness or injuriouscharacteristics by permanently displaying

bold patterns and flambouyant colors.

BATESIAN MIMICRY = the insects which istasteful or non-injurious mimic the color,

form and behavior of an injurious,distasteful insect.



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Fbs45 Lect8a Insect Behavior