Term
| name and describe different non-chemical ways that insects can avoid predators. |
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Definition
defense by hiding: crypsis (camoflauge, masquerade) and inaccessible locations
behavioral, secondary lines of defense
(thanatosis, startle response, evasive maneuers, autotomy)
mechanical/physical defenses |
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Term
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Definition
| a cryptic insect resembles its general background or an inedible object (ie hiding in plane sight) |
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Term
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Definition
| blend in to the general background |
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Term
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Definition
| resemble an object that is of no interest to the predator |
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Term
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Definition
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Term
| behavioral, secondary lines of defense |
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Definition
A. feigning death (thanatosis); fall to the ground and remain motionless
B. Take flight and flash startling color in hind wings; upon landing, fold up wings and color disappears
C. startle display, such as eyespots. research has shown that the more realistic the "eye" appears, the greater the deterrence
D. resemble a "scary" predator
E. Divert initial attack to non-critical parts of the body (eg. "tail" rather than head)
F. evasive maneuvers - cockroach escape response, dropping off plants, moth response to a bat's echolocation, many ex.
G. Autonomy - losing legs and expendable body parts |
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Term
| mechanical/physical defenses |
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Definition
A. morphological structures (spines, hairs, thickened cuticle, body shape, etc)
B. Protective structures (caddisfly larval cases, bagworms, tent caterpillars, etc)
C. sticky secretions can "gum up" enemies (aphid cornicle exudate, certain termites) |
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Term
| difference between camouflage and masquerade: |
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Definition
| the first means you resemble your surroundings, the second means you look like something you're not. |
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Term
| which insect order uses the masquerade of looking like a stick to avoid predators? |
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Definition
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Term
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Definition
feigning death
fall to the ground and remain motionless |
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Term
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Definition
| losing legs and expendable body parts--it can be adaptive! and sometimes, the only option |
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Term
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Definition
| flash startling color in hind wings - land, old wings, and disappear |
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Term
| behavioral - startle display |
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Definition
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Term
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Definition
| cockroaches, moths + bats, etc |
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Term
| name and describe different physical ways that insects can avoid predators |
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Definition
| morphological structures, protective structures, sticky secretions |
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Term
| physical - morphological structures |
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Definition
| spines, hairs, thickened cuticle, body shape, etc |
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Term
| physical - protective structures |
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Definition
| caddisfly larval cases, bagworms, tent caterpillars, etc |
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Term
| physical - sticky secretions |
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Definition
| they can "gum up" enemies (aphid cornicle exudate, certain termites) |
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Term
| name and describe different chemical ways that insects can avoid predators |
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Definition
source of chemicals (food plants, self-synthesized)
delivery method (being eaten, reflex bleeding, Urticating hairs or spines, glands, osmeterium, stings/venoms
Aposematism – warning signals (coloration, sounds)
mimicry |
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Term
| chemical defenses - types of chemicals, based on effects on predators |
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Definition
those which irritate, hurt, poison, or drug a predator. often are in combo with warning coloration in the insect (aposematic coloration)
those which are innocuous; they deter merely by foul smell or taste. tend to be volatile chemicals. |
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Term
| chemical defenses - sources of chemicals |
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Definition
food plants (insects will often sequester toxic chems from their food)
self-synthesized - eg, blister beetles |
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Term
| chemical defenses - deployment of chemicals |
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Definition
reflex bleeding (many orthoptera)
urticating hairs inject poisons into predator to cause itching or stinging (many caterpillars)
glands (stinkbugs, some beetles, venom of wasps and bees), osmeterium (eversible sacs) of swallowtail butterfly caterpillars
bombardier beetles. when threatened, the beetle contracts glands near its anus which mixes with chemicals together that create a violent heat-producing chemical reaction and a nasty chemical
venomous stings
incorporated into body, so is tasted when insect is eaten. usually associated with warning (aposematic coloration) |
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Term
| what is aposematic coloring? |
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Definition
| warning signals (coloration, smell, sounds) |
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Term
| does an aposematic signal always have to be a visual signal? |
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Definition
| no, can be a sound or smell as well |
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Term
what is mimicry?
describe the model, observer, and mimic |
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Definition
components: the model (has an effective defense, has a warning signal), the observer (associative learning), and the mimic (mimics the model but sometimes lacks the actual defense mechanism
once the observer learns to associate a negative reward (like bad taste) with aposematic signals, it learns to leave insects with those aposematic signals alone. |
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Term
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Definition
model = monarch butterfly
mimic = viceroy butterfly
observer = blue jay |
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Term
| describe and contrast Mullerian and Batesian mimicry |
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Definition
batesian: cost/benefit relationship
the mimic benefits by the presence of the protected model. the model suffers by the presence of the mimic bcs the effectiveness of the warning signal is diluted if there are lots of edible mimics. predators may be more likely to encounter an edible mimic and fail to associate aposematism with pain or distaste. predator benefits by avoiding the noxious modelm but misses a meal through failure to recognize the mimic as edible. the system holds up as long as the mimic remains less common relative to the number of models.
ex: monarch/viceroy butterfly
mullerian: model and mimics are all distasteful and have aposematic warning signals. unlike batesian in which the system can fail if the mimic becomes relatively more abundant than the model, mullerian systems gain through increased predator learning as the number of mimics increase. |
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Term
| how does a social or gregarious insect evade predators? (or lessen the impact of predation?) |
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Definition
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Term
| what kinds of defenses do these social insects have? |
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Definition
gregarious defense:
1.winter congregations of monarch butterflies in mex
2. aggregations of chemically-defended hemipterans on host plants
social insect defense:
1. nest structure is often first line of defense (hives, soil mounds)
2. alarm signals, pheromones (aphids, treehoppers, hymenoptera)
3. venomous hymenoptera (modified ovipositor)
4. workers; soldier castes (nasutiform termites, termite soldiers with well developed jaws, "exploding" termite soldiers). |
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