Gloria Luther, 28, from Sweden, said she felt sick after almost biting the larva in half.

She said: "It was disgusting. I nearly bit it in half. I felt sick. It was just sitting there in the middle of the burger.

"What worries me are all the things I might have eaten in the past and not even known about it,” she added.

The fast food giant has blamed their green environmental policies for the incident, as reported in the Austrian Times.

McDonald's spokeswoman Claes Eliasson said: "There always is a risk that there are larvae because our suppliers don't spray any pesticides on their lettuce but wash them in water.