Natures wonders: insect hibernation (Introduction)

by David Turell , Monday, October 22, 2018, 21:37 (2013 days ago) @ David Turell

Only its called diapause:

https://blogs.scientificamerican.com/observations/how-insects-prepare-for-winter/?utm_s...

"Insect diapause is a lot like hibernation, but there are some differences. The main difference is that mammals remain active until winter is well established and temperatures are frigid, but insects that enter diapause become dormant in the autumn well before it gets too cold for them to function. Another difference is that mammals can sometimes rouse themselves for short periods of activity during the winter, but once an insect enters diapause it will remain dormant until spring even though the weather might be suitable for normal growth and development.

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"When insects enter diapause, they stop developing and spend a prolonged period in a single developmental stage. All insects start as embryos inside an egg and proceed through their life cycle becoming larvae, pupae (when metamorphosis occurs) and finally adults. As a group, insects can enter diapause at any stage, but the stage when each species enters diapause is programmed in their genes. The Asian tiger mosquito, Aedes albopictus, which is involved in spreading diseases like dengue fever, and the silkworm, Bombyx mori, which is important for silk production, both enter diapause as embryos. The corn earworm, Helicoverpa zea, which can put a damper on your summer barbecue if you find one in your ear of corn, enters diapause in the pupal stage. The mosquito Culex pipiens, which spreads West Nile virus, enters diapause during the adult stage; and it is only the females that can survive the winter.

"In addition to developmental arrest, entering diapause includes a reduction in metabolic rate that is sometimes so extreme that oxygen consumption is almost undetectable. This, together with arrested development, reduces the insect’s need burn the stores of fats and carbohydrates that are built up before they become dormant. This makes fuel stores last longer and insures there is enough gas in the tank, so to speak, when it is time to restart normal activities in the spring. The energy saved can also be channeled toward producing proteins, sugar alcohols and other substances that act like antifreeze and keep delicate membranes and other structures in the body from being damaged by cold, dehydration or insufficient oxygen.

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"Knowledge of genome structure and function has led to some significant breakthroughs in our understanding of the specific genes or gene networks that are turned on and off before, during and after diapause. We know, for example, that changes in how insulin is produced and used is important for diapause. We’ve also learned that changes in the regulation of proteins that govern the circadian clock (the internal system that measures day length) are important for deciding if it is time to prepare for diapause."

Comment: This process is not fully understood but is under study. This process saves insects over the hard time of winter. It could not have developed stepwise by chance or the insects would not have survived. with the necessary complex metabolic changes involved, Only design explains this.