Cool weather lovers take heart; the first frost is coming in less than six weeks. How do I know? Annual cicadas know.

Weather watchers have seen (and heard) the signs. Annual cicadas have emerged and lore suggests that the first frost occurs six weeks after they begin to sing. These large black, brown and green insects are unmistakable and can make quite a racket. They have wide-set eyes and striking translucent wings that extend past their bodies. Males have a special membrane under their exoskeleton called a tymbal that vibrates and produces sound.

This sound, only produced during the day, is employed by males to attract females and can be heard up to a half a mile away. The cicada’s music is notable because it is the loudest sound any insect is known to make. Interestingly, as a pair gets closer together, the male’s call gets softer. 

While most of us begrudged the hot weather of late, cicadas come alive in the hottest of days. The dog days of summer give rise to these so-called dog day cicadas.

Dog day, or annual, cicadas relish the high temperatures, which warm the air and soils, and encourage their emergence from their below-ground environs, usually in mid July. Larval annual cicadas spend two to five years underground sucking liquid nourishment from tree roots and waiting for their summer to begin. Their emergence is staggered so that some come out every year, thus their name. 

Their more famous cousins are the periodic cicadas that notoriously swarm en masse, emerging from the ground every 13 to 17 years. Since the next major emergence of periodic cicadas in Massachusetts won’t be until 2025, you must rely on the annual dog day cicadas for their mid-summer appearance and your frost forecast.

Take advantage of their presence for forecasts as well as for food. Cicadas might just be the next big thing in protein consumption. Both types of cicadas are edible, though not recommended for everyone. Since cicadas are arthropods, like lobsters, crab and shrimp, folks with shellfish or seafood allergies might be wise to not partake of them since these species are related.

The best time to harvest cicadas is right after they shed their nymph skin, when they are in their teneral stage and are still soft. This occurs after the larva emerges from the ground and breaks free of its larval skin, but before its new shell hardens. If you can’t find them this way, the next best eating cicada is the female, which is full of sweet eggs. Don’t bother with the males as they tend to be bitter.

If you find enough cicadas for a snack, remove their wings and legs (to reduce bitterness), boil for a few minutes and season as needed. Better yet, cover them with chocolate.

Pound for pound, cicadas have as much protein as beef and taste somewhat nutty and a bit like asparagus. It is no wonder then that they care called the “shrimp of the land.” Don’t overdo your consumption, though, since some sources note that they can be high in mercury.

Vincent Van Gogh felt a kinship with these summer insects, writing: “I work even in the middle of the day, in the full sunshine and I enjoy it like a cicada.”   

If the artist didn’t let the heat bother him, we shouldn’t either. Nor should we refuse enjoyment from these insects in all of their roles, as our beat the heat inspiration, summer songster sidekicks and perhaps even as our delicious desserts.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature