Genetic Allee Effects for Controlling Invasive Populations

Area of Science:

• Ecology
• Genetics
• Invasive Species Management

Background:

• Invasive pests pose significant threats to food security and ecosystems.
• Early detection of small invasive populations is difficult, hindering management.
• Allee effects, where population growth rate decreases at low densities, are rare in invasive species but could aid control.

Purpose of the Study:

• To investigate the potential of imposing a genetic Allee effect using genetic load.
• To assess how introducing deleterious recessive alleles impacts the establishment probability of small invasive founder populations.

Main Methods:

• Numerical and individual-based modeling were employed.
• Simulations examined populations with deleterious recessive alleles sourced from a larger invasive population.
• Analysis focused on the impact of genetic load unmasked during population founding.

Main Results:

• Genetic load significantly reduced the establishment probability of small invasive populations across various parameters.
• Sterile mutations were more effective than lethal mutations; X-linkage provided minimal advantage over autosomal inheritance.
• Distributing low-frequency deleterious alleles across many loci was more effective than high-frequency alleles across fewer loci.

Conclusions:

• Imposing a genetic Allee effect through genetic load is a viable strategy to reduce invasive species establishment.
• This approach can make invasive source populations less likely to establish in new environments.
• Management strategies could involve pre-emptively introducing deleterious recessives into potential source populations.