Citizen scientist records of Eriosoma lanigerum on iNaturalist.

Eriosoma lanigerum, aka the woolly apple aphid (WAA), is native to Eastern North America where it typically feeds on native hardwood trees. When apples were introduced from Europe, the WAA switched hosts and has been a perennial pest in orchards since it was identified in 1842. WAA is now globally distributed and represents a significant challenge to apple production and export.

Management of WAA has relied on rootstock resistance to minimize perpetual below ground populations and chemical or biological control to reduce seasonal above ground colonies. In the past, rootstocks containing resistance (Er) genes have reliably provided below ground control, but populations around the world are adapting and overcoming resistance. At least one new genotype has emerged that has broken through rootstock resistance. 

Our project investigates how WAA adapts to apple cultivars and what growing regions can do to prevent this adaptation to sustain efficient production.

To get the research going, we were funded by the USDA with these original objectives:

• Objective 1, to identify gene presence and expression in our resistance breaking population, is completed and we are transitioning into sample processing.
• Objective 2, to look for this genotype across the US, is in its final year of sampling.
• Object 3, to link aphid molecules to their targets in apple, is half way complete, with the lab bench pipeline developed and trialed on known aphid effectors.
  

2025 Update
We finally received all the sequence data, polished the metadata, and are moving through the bioinformatics pipeline. 

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