Sterile Insect Technique (SIT): A method of biological pest control.

Scientists and researchers in Argentina are a case and point of how to successfully use nuclear technology to control pest populations.

The Mediterranean Fruit Flies rapid proliferation and spread throughout western Argentina has caused widespread damage to the regions fruit industry, with farmers loosing 30% of their crop during export control, or shouldering the high costs of post-harvest treatments to kill the flies larvae alongside the associated environmental and health risks with heavy pesticide use.

The solution to this damaging insect pest costing this vital industry millions per year was engineered in an insect factory in Mendoza, their ‘product’: Sterilized Mediterranean fruit flies. Their method: SIT (Sterile Insect Technique). Their partners since the 1990’s: the IAEA and FAO.

This complex process is split into several parts:

Separation of the female and male eggs.

Through keeping the eggs in water and increasing the temperature to 34 degrees Celsius the female eggs are killed while the male eggs survive.

Rearing the eggs to larvae and pupae.

This is completed in a controlled environment, where the temperature and humidity are kept the same as conditions in nature.

Dying the pupae bright colours for identification

Sterilization using ionizing radiation

Care until sexual maturation followed by targeted release into the wild

The sterilized male insects then compete with wild males to mate with females, producing eggs which are infertile and bear no offspring, with the overall effect of reducing the insect population.

Thanks to the integrated pest management approach, including area-wide SIT, Argentina has declared Patagonia free of the Mediterranean Fruit Fly, with fly populations kept at very low levels in the regions close to Mendoza province.

The success of SIT against the Mediterranean Fruit Fly opens the possibility of using this technique against other insects, such as the Aedes Aegypti Mosquito known for the transmission of Zika, Dengue and Chikungunya. While targeting Aedes Aegypti is still at early research stage, the future of this technique looks hopeful.