Last blood meal found in 46-million-year-old mosquito

15 October 2013

The contents of the distended belly of an ancient female mosquito help create a tantalising glimpse into the past.

An international team of scientists, including Museum mosquito expert Dr Ralph Harbach, have successfully identified an organic compound known as haem in the abdomen of a fosilised mosquito that died 46 million years ago.

Haem is found in haemoglobin, the red pigment in blood. The fossil of the blood-engored mosquito, that died immediately after feeding, was preserved in oil shale, a type of rock from northwest Montana, USA.

It's very rare for something as fragile as a distended belly to be so well preserved.

The researchers used cutting-edge chemistry techniques, including a scanning electron microscope, to study the female mosquito. 

Opening the door to further discoveries

Their findings confirm that certain molecules can survive tens of millions of years, which opens the door to identifying other organic molecules in fossils, such as eye pigments.

'Our findings are a tantalising glimpse into the past,' said Dr Harbach. 'They help us build up a general picture of where the mosquito was living and what the environment was like.'

This mosquito probably lived around a large shallow body of water in a wet, sub-tropical environment, among fauna closely related to that now found in the tropics and subtropics. Average temperatures were around 15 degrees higher than today. 

Ralph Harbach on mosquitoes