Sefer HaChinuch ספר החינוך

The commandment of checking the signs of grasshoppers: To check the signs of grasshoppers — and these are the signs that are written in the Torah, “that has jointed legs above its feet, etc.” (Leviticus 11:21), as it is stated, “this you may eat from all the winged swarming things.” And the content of its root is like with the other species.

Its laws: They, may their memory be blessed, explained (Chullin 65a) that eight types of grasshoppers are pure. And these are them: The first is called grasshopper; the second is called duvanit, and it is a type of grasshopper; the third is called cricket; the fourth is the utsravia, and it is a type of cricket; the fifth is the locust; the sixth is the “bird of the vineyards,” and it is a type of locust; the seventh is the bald locust; [and] the eighth is the Jerusalem yochana and it is a type of bald locust. One who is an expert can check them based on his expertise and their names, and eat [them]. And an Israelite trapper is trusted about them and about fowl. And one who is not an expert about them checks with the signs that the Torah gave about them. And there are three signs — and these are them: Four wings that cover most of the length and most of the width of its body; four legs; and two jointed legs with which to hop on the ground. And some say that he needs to know the name of the grasshopper. And the rest of its details are elucidated in the third chapter of Chullin. (See Tur, Yoreh Deah 85.)

And [it] is practiced in all places and at all times by males and females. And one who transgresses it and eats without checking properly has violated a positive commandment.