The first five minutes of this giant monster movie consists of maps and stock footage about radar, then one of these Northern radar stations is attacked. Then an airplane is attacked and the only clue is a part of a broken claw. But the authorities can't figure out what it is, until they employ a paleontologist who says it comes from an insect. A very big insect.
A giant preying mantis has awoken from its icy slumber in the North Pole and is making its way South, attacking ships and eating people along the way. They basically end up spraying it with bug spray (nerve toxin) to kill it.
The effects of the giant mantis are good, though I particularly liked that shot of them using a real one climbing up the side of a miniature George Washington monument.