These alien looking insects spend 17 years underground as larvae sucking sap from tree roots and spend just one summer singing as adults. But now nutritionists are looking at them as at a precious aliment: cicadas contain the same protein amount as red meat (pound per pound) and many vitamins and minerals.

"They're high in protein, low in fat, no carbs. They're quite nutritious, a good set of vitamins. The plant-based diet gives them a green, asparagus-like flavor, especially when eaten raw or boiled," said Gene Kritsky, a biologist and cicada expert at the College of Mount St. Joseph in Cincinnati, Ohio.

The last major cicada outbreak took place in 2004. Billions of new cicadas are going to emerge in the midwestern United States and their descendants will get out of the ground just 17 years later.

"Crayfish, lobsters, crabs, and shrimp are part of the same biological phylum-arthropods-as insects. So popping a big juicy beetle, cricket, or cicada into your mouth is only a step away," said Jenna Jadin, an entomology graduate student at the University of Maryland.

"I like chocolate, and chocolate-covered insects are common worldwide. We'll see how comparable they are to chocolate-covered crickets." she said.

"Eating insects for food is common throughout the world and dates back thousands of years," said Kritsky.

In Africa scarab beetles and termites are considered delicacies. In Thailand, silkworms, grasshoppers and water bugs are heavily consumed. Movie theaters in South America sell roasted ants as snacks and in Japanese supermarkets you will find aquatic insect larvae. Living stinky bugs are eaten as spice in Mexico.

Like all foods, certain people could have an allergic reaction to cicadas, even if by now there is no evidence of it. The main concern are not cicadas by themselves, but the pesticides and herbicides they could have absorbed.

"Given that it's likely people won't be feasting on cicadas, just eating a few of them-even if they have [absorbed] chemicals, it's no worse than eating fish from the Great Lakes." Jadin said.

David George Gordon, a science writer in Port Townsend, Washington, has even imagined a recipe for cicada-topped pizza.

The best cicadas are those freshly hatched from nymphs (tenerals), before their exoskeletons turn black and hard.

"They are best collected in the early morning hours, just after the insects emerge from the ground but before they crawl up trees, where they are harder to reach." said Jadin.

If tenerals are missed, the next best item are adult females, with bellies filled with nutritious eggs. Adult males can be discarded as their abdomens are hollow, making room for their tymbals, the organs that emit the cicadas' songs.

"Most people like them deep fried and dipped in a sauce like a hot mustard or cocktail sauce. Other people boil or blanch them. " Kritsky said.

"Cicadas take on a "nutty" flavor when roasted. Many cicada recipes call for a lot of spices and sauce, which usually wind up being the dominant flavors. " said Jadin.