Female Anopheles mosquitoes cannot tell if males they have mated with are fertile or infertile a study has shown.
And the female insect only mates once in her life before laying a batch of eggs.
A female who mates with a spermless male subsequently produces eggs that are unfertilised 'blanks'.
These eggs never hatch into future generations of malaria-carrying mosquitoes.
Lead researcher Dr Flaminia Catteruccia, from Imperial College London, said: 'In the fight against malaria, many hope that the ability to genetically control the mosquito vector will one day be a key part of our armoury.
'In order for these currently theoretical control strategies to work, we need to make sure that the insects continue to mate as normal, unaware that we have interfered with their sexual mechanisms.
'This study strongly suggests that they cannot tell the difference between a fertile and a spermless mate.'
The study showed they did not.
Scientists were also surprised to find that after mating with a spermless male, the female made no attempt to find a fertile replacement.
The research was published today in the journal Proceedings of the National Academy of Scientists.
A hundred spermless males were produced for the study by injecting mosquito eggs with a protein that disrupted male sexual development.
Importantly, although the adult males were unable to produce sperm, they retained their ability to mate.
Scientists at Imperial College London were surprised to find that after mating with a spermless male, the female made no attempt to find a fertile replacement
Laboratory observation showed the males produced seminal fluid devoid of sperm that triggered normal physiological changes in females.
The female laid the usual number of eggs, and abstained from sex after their first mating encounter.
Malaria is a huge worldwide problem that affects more than 300 million people each year and causes almost 800,000 deaths.
The study focused on the mosquito species Anopheles gambiae which is chiefly responsible for spreading malaria in Africa.
