Creatures most of us would rather swat, spray or squish are the subject of a scientific meeting in northeastern Iowa today. The 11th annual Prairie Invertebrates Conference will deal with the preservation of insects, spiders, worms and other bugs that live in Midwestern grasslands. He says many are important in pollinating plants, they also serve as food for bigger animals.Kirk Larsen is a biology professor at Luther College in Decorah, which is hosting the conference. He says a typical patch of tallgrass prairie might have 500 species of plants and 10-thousand species of insects. Larsen says one chief threat to the “crucial” insects is the use of fire to manage prairies. He says sometimes the timing of fires isn’t good and hurts insects.Larsen says prairies are so isolated now that there are no nearby patches from which burned areas can be re-populated with insects.A century and a half ago, Iowa may’ve had 30-million acres of prairie. Today, Larsen says it’s more like 20-thousand acres, if that.