Erin Patterson's murder convictions for the deaths by mushroom poisoning of her estranged husband's relatives has prompted fevered speculation across Australia about her motive.

Some businesses say mushroom foraging tours are becoming unviable due to higher insurance costs, as Erin Patterson's triple-murder trial sparks more interest in fungi.

The Australian woman was convicted of murdering three elderly relatives of her estranged husband with a meal laced with poisonous mushrooms, and attempting to murder a fourth, in a case that gripped the country.