TT #148 · Parshas Shemini · Aliyah 6 · Passuk 21
Chabad.org — Vayikra Chapter 11 with Rashi
English: However, these you may eat among all the winged swarming things that walk on four legs: those that have jointed legs above their feet, with which to leap on the ground.
Chullin 65a.
E-Daf.com — Chullin 65a (Tsurras Hadaf)
אֲשֶׁר לֹא כְרָעַיִם. [כְּתִיב לֹא קְרֵינַן לוֹ, מְלַמֵּד] שֶׁאֲפִלּוּ אֵין לוֹ עַכְשָׁו וְעָתִיד לְגַדֵּל לְאַחַר זְמַן, כְּגוֹן הַזָּחָל – מֻתָּר.
Textual reading — The unusual form of the verse teaches that a creature destined to develop the required legs may already be eaten at the earlier stage.
A locust-like creature may be permitted even if its legs are not yet developed, when they will grow later.