Who likes Californian Eucalyptus?
Measuring insect biodiversity on invasive Eucalyptus in California.
For those of us who have spent much time in the Bay Area, trees of the Eucalyptus genus are familiar and often dear to our hearts. Many are grown ornamentally, due to their beauty and fragrance. One species, however, has successfully escaped cultivation and become a serious environmental issue. Eucalyptus globulus is an Australian tree introduced to California in around 1865 (US Forest Service 2013) and has become naturalized along the entire coast. The tree is notorious for displacing native flora and for being a potential fire hazard due to the large amounts of volatile oils the plant contains. What is not well understood, however, are its effects on the Californian insect biota.
Eucalyptus poses a direct threat to living organisms that it comes into contact with. Eucalyptus is a heavily defended plant, and essential oils distilled from the plant have fumigant effects strong enough to warrant commercial interest (Negahban and Moharramipour 2007). This toxicity makes it difficult for non-adapted hosts to feed on the plant, and could potentially deter insects from associating with the plant at all. These aromatic chemicals could also play a part in its alleged flammability and likely play a role in the allelopathic behavior of the tree.
