4980797
| Question | Answer |
| What are the 3 tagmanta of anthropods? | head thorax abdomen |
| ametabolous | offspring gradually assume adult characters through a series of moults no metamorphosis – primitive (wingless species) |
| hemimetabolous | adult form is attained by a series of moults and metamorphosis is incomplete – partial metamorphosis – all immature stages are called nymphs – nymphs resemble adults except that wings and genitalia are acquired at the final moult |
| holometabolous | distinct metamorphosis with well defined larval and adult stages – full metamorphosis more advanced |
| Arthropoda | • large phylum – insects, arachnids, crustaceans and many other smaller groups |
| Coleoptera | beetles 300,000 species |
| Hymenoptera | bees, wasps, ants 100,000 species |
| Lepidoptera | butterflies and moths 110,000 species |
| Diptera | flies 100,000 species |
| trehalose | antifreeze produced by Morulina mackenziana |
| Q: How do you sample collembolas? | A: with a pooter |
| The Arctic is tough for insects because | • short growing season • low humidity • low precipitation • low incident radiation • poor quality soils • low primary productivity • most important factor is the year-round low mean temperatures – limits development and reproduction – threatens survival in winter |
| Why are arthropods important? | • roles – scavengers, decomposers, pollinators, herbivores, predators, parasitoids, nutrient cycling, litter decomposition, soil structure • food for wildlife • vectors of disease • plant pollination • wildlife impacts • economic importance |
| Why are arthropods so successful? | • colonization predates the chordates • flight • small size • body structure • metamorphosis • high birthrate, low generation time • life history traits |
| chionophobe | do not inhabit snowy regions year-round, but migrate to warmer climates |
| • chioneuphore | withstand winters with considerable snowfall |
| • chionophiles | inhabit regions with long, cold, snowy winters and exhibit special adaptations |
| poikilothermy | body temperature is variable and dependent on ambient temperature (arthropods) |
| northern insects are cold-adapted | metabolic rate is higher at a given temperature than in related forms from warmer regions |
| stoneflies (Nemoura columbiana) | can emerge from an ice-covered stream and mate in the air space beneath the ice and snow cover at an air temperature of 0°C without incident radiation |
| Chernov’s lifecycle categories : • Active | adaptation for rapid development and able to pass winter in only one stage (e.g., social bees, orb-web spiders) |
| Chernov’s lifecycle categories : passive | adaptation whereby a particular lifecycle stage is extended for several years and able to pass the winter in many stages (e.g., lymantriid moths) |
| Dormancy | development from egg to adult is interrupted |
| quiescence | halted or slowed development as a result of unfavorable conditions |
| diapause | “metabolic shutdown”, or arrested development combined with adaptive physiological changes |
| Voltinism | # generations/year |
| semivoltine | >1 year/cycle |
| univoltine | 1 year/cycle |
| bivoltine | 2 cycles/year |
| multivoltine | >2 cycles/year |
| Directly Induced Development (DID) | development is a function of temperature: • NOT dependent on anticipatory cues |
| Cue Induced Development (CID) | – diapause occurs in response to some type of cue, which precedes the onset of unfavorable conditions (e.g., photoperiod) |
| cold-hardiness | the ability of an organism to survive at low temperatures |
| cold-acclimation | the seasonal increase in coldhardiness that occurs in most northern species from summer to winter to prevent cryoinjury |
| Freezing Avoidance | – insects keep their body fluids liquid below their ordinary melting point (supercooling) unable to survive formation of ice in body tissues and fluids |
| Freezing Tolerance | strategy for species that tolerate formation of ice in body tissues and fluids; generally only extracellular freezing is tolerated |
| Cryoprotective dehydration | – depress melting point by keeping their body fluids in vapour pressure equilibrium with the surrounding ice – held above ice nucleation temperature for a sufficient time, or are cooled slowly, enough water is lost to prevent freezing (cryoprotective dehydration) |
| Freezing tolerance | freezing is initiated by ice nucleators in the haemolymph or gut • polyols and sugars protect membranes and proteins against phase transitions and control the ice fraction size and minimum cell volume |
| Freeze tolerance compounds | Cryoprotectants Thermal Hysteresis Proteins (THP) Ice Nucleating Agents (INA) |
| Cryoprotectants | – polyols and carbohydrates (e.g., glycerol) associated with membrane protection and repair at freezing temperatures |
| Thermal Hysteresis Proteins (THP) | – freezing of hemolymph (insect blood) is depressed relative to melting point – proteins bind to ice crystals to slow growth |
| Ice Nucleating Agents (INA) | molecules or particles that induce ice formation in extracellular fluid a few degrees below zero • minimizes intracellular freezing |
| Summer months – evaporative cooling (regurgitated fluid) | • high temperatures honeybees repeatedly regurgitate a droplet of fluid and suck it back in |
| Winter months | – anaerobiosis (anoxia) • life sustained in the absence of oxygen – drought resistance |
Want to create your own Flashcards for free with GoConqr? Learn more.