RIDL® technology

RIDL employs modern biotechnology to provide effective, clean control of insect pests.

RIDL insects contain a modification that causes their offspring to die, but can live and reproduce normally when the larvae are fed a diet containing a supplement. RIDL males are released to mate with wild female pest insects; their progeny inherit the RIDL gene and do not survive to adulthood. Releases of RIDL males in large enough numbers over a sufficient time will suppress, or even eliminate, the target pest population. The conditional lethal attribute protects against the hazard of accidental release. If RIDL insects were to escape from a rearing facility, they would be unable to reproduce because they would not have access to the diet supplement.

Bisex RIDL strains have no progeny unless supplied with the supplement; both male and female progeny die. Strains can be designed to die at different life stages. Released bisex RIDL insects and all of their progeny die within a few weeks so releases must be sustained to maintain the control. Where a male-only release is required, the sexes must be separated mechanically, which is possible in only a few insect species. Bisex RIDL is included is Oxitec’s products Aedes aegypti OX513A and pink bollworm OX3402.

Female-specific RIDL (fsRIDL) strains have no female progeny unless supplied with the supplement, but male progeny survive. Strains can be designed to die at different life stages. The sexes can be separated easily by including the supplement from the diet of the final, pre-release generation so that only males are produced for release. This eliminates potential damage caused by handling in mechanical sex separation. fsRIDL males are released to mate with wild type females. Their female progeny do not survive and the population is thereby suppressed. Their male progeny carry one copy of the RIDL gene, so half their female progeny will also die. There is therefore some carry-through of the birth control activity but releases must be continued for total control. fsRIDL is included in Oxitec’s products Aedes aegypti OX3604C and Mediterranean fruit fly OX3647.