Tennessee Warbler. Order: Passeriformes Family: Parulidae Genus: Oreothlypis Species: O. peregrina Binomial name Oreothlypis peregrina (Wilson, 1811). The Tennessee warbler feeds mainly on insects and prefers the spruce budworm. This species fluctuates in population with the quantity of the worms. It also likes flower nectar, fruit and some seeds. This warbler, like most others, is nervous and quick while foraging. It creeps along branches and is found at all levels.