A study published in 2004 of the effect on Battus philenor in the San Francisco area found that gardens where the host plants were more than 40 years old, the gardens were as good as natural sites, where the host plants were less than eight years old the species was unlikely to visit, and in between the butterflies laid eggs but these had an inferior survival rate.
Battus polystictus | Battus polydamas | Battus philenor hirsuta | Battus philenor |
The larva of the California pipevine swallowtail (Battus philenor hirsuta) relies on California pipevine as its only food source.