Eucalyptus

Eucalyptus is a genus of over 700 species of flowering and mostly evergreen trees from the Myrtaceae (myrtle) family, predominant in Australia.
Eucalyptus oil is distilled from the leaves of the tree.

Eucalyptus is a natural antiseptic and a disinfectant. It helps with bronchial congestion and other symptoms of the common cold.

Eucalyptus & Insects

Eucalyptus oil is a natural insecticide.

Folk remedy
Eucalyptus tea is the traditional remedy of Australian Aboriginals for the common cold, stuffy nose, fever, or pains.

Toxicity

Eucalyptus oil is safe only when used as recommended, but toxic if ingested in large quantities.