Halakhah do Kapłańska 11:21

That is that He commanded us to check for the signs of locusts as well. And [the signs] are written in the Torah - "all [...] that have, above their feet, jointed legs" (Leviticus 11:21). And the content of this commandment is like that which we explained in the commandment before this; and the verse about it is His saying, "Of these you may eat the following - locusts" (Leviticus 11:22). And the laws of this commandment have already been explained in Tractate Chullin. (See Parashat Shemini; Mishneh Torah, Forbidden Foods 1.)

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.