Responsa do Kapłańska 11:29

I also asked [in my dream] regarding beans and other legumes that contain insects known as kanetons¹possibly referring to the French hanneton, the insect or larvae of Melolontha beetles. Cf. Rashi on Avodah Zarah 28b:5 . Mishnah Machshirin 6:1 refers to an insect called כנימה, which Rashi on Chullin 13a:4 explains as 'the coçons (cocoons) that grow in beans and lentils'. They may be forbidden, since we might assume that the insects developed while the food was attached to the plant, and the insects are therefore classified as the forbidden "things that swarm upon the earth."(Leviticus 11:29). We might also assume that the insects developed after they were picked, and therefore do not fall into this category and are permitted.²See previous question for the discussion of whether the insects were created while the fruit was attached to the ground renders them as 'swarming on the earth' and thus forbidden. Rashba (Torat Habayit Hakatzar III:3) describes two kinds of insects that may be present in beans, one that develops while the bean is attached and the second once detached, and thus recommends soaking the beans before cooking.