Nobody knows what happened to the insects as they had grown a lot larger. Now, they want to erase the entire human race in the face of the planet. Well, actually, they just want the human race as their food, but mankind isn't going to sit this one out as they sent their best man to eliminate the problem. The idea here is to eliminate the insects. You need to shoot them all till they are done. Do not forget to destroy the flowers since that is where they are coming from. The insects would just keep on coming if you don't destroy the flowers.