some type of beetle, possibly a black beetle (see Molina)
IPAspelling:
temoːlin
Alonso de Molina:
temolin. cierto escarauajo, o tauano. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 97v. col. 2. Thanks to Joe Campbell for providing the transcription.