Australians vary in their use of the digraph ae. We tend to make it just e when it occurs in the middle of a multisyllable word, but usually keep ae at the beginning of a word or in the first syllable:

The ae digraph that marks the plural form of Latin nouns ending in -a (eg larvae, pupae) is usually retained in scientific writing. Other kinds of Latin nouns (eg formula, persona) usually take English plurals (formulas, personas).