Aphids are abundant, outbreaking insect herbivores that can deal considerable economic damage to cereals and legumes due to pathogens they transmit. While aphid-virus outbreaks can have catastrophic impacts on crops, we do not yet have reliable population models that predict the time and location for areas at high risk for aphid-virus outbreaks. Because these tools are not available, growers in the Palouse have resorted to intensive chemical control, treating all plants before outbreaks can occur to prevent yield losses. However, many insecticide applications are unnecessary because aphid outbreaks are intermittent, typically occurring only every 4-8 years. Aphid outbreaks are also typically isolated to certain subregions of the Palouse in any given year, and only growers in those subregions may need to use insecticides. In this project, we hope to dramatically reduce the reliance on chemical controls as a preventative measure by developing predictive models that can tell growers ahead of time if outbreaks are unlikely to occur. This new advancement is based on our past work that has identified early-season hosts that can harbor aphids an entire month before spring pea and summer wheat have sprouted. This suggests that if we can detect high (or low) levels of aphids in these alternative hosts, we can make predictions about risk to crops in each area. If successful, these models will be able to provide pulse and cereal growers with an “early warning” map of risk from aphids. To this end, our project has three goals: (1) Identify which alternative host plants harbor outbreaking pea aphids and cereal aphids, (2) Develop predictive, landscape-scale statistical models for summer outbreaks based on early-season data, and (3) field-test these models to assess how large an area alternative hosts can predict outbreaks, and once this is known, produce risk maps that are available to growers online. This approach has been successful in potato crops for pests that spread pathogens. Our goal is that by providing more reliable information on aphid risk to growers, we can reduce the overall intensity of cereal-legume production and insecticide sprays in particular.
- Principal Investigator(s): Crowder, D.
- Investigator(s): Clack, R.
- Grant Amount: $40000