Sex or poison? Genetic pest management in the 21st century
Sex or poison? Genetic pest management in the 21st century
Tags: Mosquitoes, Pest management, Sterile insect technique (SIT)Luke Alphey, BMC Biology, 21:289. 2024.
Pests do enormous damage to human and animal health, to agriculture and to biodiversity, with mosquitoes transmitting pathogens, insect larvae eating crops or invasive rodents threatening the last island refuges of endangered birds. This commentary focuses on insects, particularly mosquitoes. However, most considerations apply equally to other pest species. Genetic pest management (GPM) is the use of genetics to control pests through mating of modified pests with their wildtype counterparts. This allows heritable traits to be transferred (“introgressed”) into the wild pest population. In principle, any sexually reproducing pest species can be targeted.
The aim is to reduce harm done by the pest population, with typical intended outcomes overwhelmingly falling into two types: population suppression and population modification. For population suppression, one would introgress fitness-reducing traits, such as lethality or sterility, leading to reduction in the numerical size of the pest populations if spread into the target population at sufficiently high frequency. Population modification aims to reduce the harm done by the pest without large changes in the numerical size of the pest population, for example by reducing the ability to transmit disease (“vector competence”) of modified mosquitoes. If such traits, or the DNA sequences encoding them, can be sustained at sufficiently high allele frequency in the target population then the desired harm-reduction outcome should be achieved, by reduction in the number of pests or by reduction in the per-pest harm.