Sexual frustration will give you a shorter and more stressful life (if you are a fruit fly)

Sexually frustrated fruit flies die earlier (Getty Images)

Sexually frustrated fruit flies die earlier, new research suggests.

Scientists made the discovery by genetically modifying male flies to release female sex pheromones. Other males were left nearby and therefore instantly aroused by the pheromones. Some were allowed to mate, but others weren't.

The findings, published in the journal Science, show that the sexually frustrated flies' lives were 40 per cent shorter, while those who did mate suffered less stress.

Dr Scott Pletcher, Assistant Professor of Molecular & Integrative Physiology at the University of Michigan, co-authored the research. He told the BBC: "We immediately observed that (the non-mating flies) looked quite sick very soon in the presence of these effeminised males."

A brain chemical, neuropeptide F (NPF), appeared to play a big role. NPF levels went up once flies were aroused. It would normally go down again upon mating.

But when it stayed high, it caused the stress and apparently the premature deaths.

Dr Pletcher went on: "Evolutionarily we hypothesise the animals are making a bet to determine that mating will happen soon.

"Those that correctly predict may be in a better position, they either produce more sperm or devote more energy to reproduction in expectation, and this may have some consequences [if they do not mate]."