At any time, it is estimated that there are some 10 quintillion (10,000,000,000,000,000,000) individual insects alive.
In the United States, the number of described species is approximately 91,000. The undescribed species of insects in the United States, however, is estimated at some 73,000.
According to Smithsonian Institutions
According to all the reports I have seen or heard it is impossible for insects to grow to extreme sizes due to the lack of oxygen within the environment. That would be my luck, to run into a spider that was over 4 foot. “Giant Megloptera found – Bigger bugs being identified” Make sure you watch both videos, it is wicked scary!