Manusmriti
मैत्राक्षज्योतिकः प्रेतो वैश्यो भवति पूयभुक् । चैलाशकश्च भवति शूद्रो धर्मात् स्वकाच्च्युतः ॥ ७२ ॥
A Vaisya who has fallen off from his duty becomes a Maitrakshagyotika Preta, who feeds on pus; and a Sudra, a Kailasaka (Preta, who feeds on moths).
english translation
maitrAkSajyotikaH preto vaizyo bhavati pUyabhuk । cailAzakazca bhavati zUdro dharmAt svakAccyutaH ॥ 72 ॥
hk transliteration by Sanscript