Presentation on theme: "By Albert Zheng. Going Dormant Some insects go dormant. Go into a state diapause Can withstand lower temperature than those who remain active and longer."— Presentation transcript:
Going Dormant Some insects go dormant. Go into a state diapause Can withstand lower temperature than those who remain active and longer survival time Some can survive in -42 degrees Celsius.
Diapause Two Class of diapause. Freeze Susceptible Insects Avoids freezing temps, depends on antifreeze compounds Main compound is Glycerol High viscosity in low temps. Keeps body fluid and tissue from freezing Freeze Tolerant Insects Only the body fluid freezes, freezing the living cells forcing water out of the cell making it more tolerant to freezing cold temp. Called cryoprotectant
Torpor A temporary state of suspension and sleep, which makes the insect completely immobile. Example: New Zealand weta, flightless cricket, that likes to live in high altitude. In the evening, it would freeze solid and in daylight, warms it up and comes out of torpid state and resumes activity
Remain Active The honey bees would cluster together and use their body heat to keep themselves and their brood warm. Lady bugs lays on top of each other under rocks to share heat. Grasshoppers lay there eggs deep in the ground to keep warm. Ants and termites head below the frost line where there they store their food to last all winter.
Size Matters Insects are like bags of water. So the larger they are, the more water they will contain. The smaller arthropods, like ants and tiny spiders, can withstand more harsh temps than bigger ones like the grasshopper. True about the same species too, ex: a smaller house fly will last longer than a larger one.
Moisture A dry environment is more beneficial for some insects to survive in than humid environment. For example the freezing point of a housefly can be lowered by 50 degrees if it is dehydrated.
Nutrition An insect with an empty gut will last longer than an insect with a full belly. Food extracts water that can freeze and form ice crystals which will freeze an insect quicker.
Temperature The intensity and duration of the cold temperature is critical to an insects survival. If exposed to long in these temps, the insects will die, even in moderate cold temps.
Migration Some insects migrates to warmer climates. Like the Monarch and Painted Lady Butterfly. Migrate south in late summer and return in the spring. Will fly up to 2000 miles to spend winter in Mexico Many other butterflys and moths migrates seasonally too. black cutworm, fall armyworm, green darners. Other insects migrate only to nearby habitat For example fields to woodlands, groves, hedges, or shelterbelts.
Growth Stages Some stages an insect can be in to survive longer than others that are not in these stages. The non-feeding stage like egg and pupae. Others build protective structures like cocoons and papae. Like tomato hornworms who spends their winters in a pupal stage and buries itself several inches deep in soil. No surface moisture that could cause freezing. Eggs; Ex: Praying Mantids stay as eggs in the winter Larvae; Ex: Woolly bear caterpillars curl up in thick layers of leaf litter. Pupa; Ex: Black swallowtails chrysalides in the winter. Adults; Ex: Morning cloak butterflies hibernate as an adult for winter, tucking themselves behind loose bark or tree cavity.
Environment In the winter, light fuffy snow can provide an insect insulation more than packed snow.