SOUTH DAKOTA COUNTY RISK ASSESSMENT MODEL FOR CORN INSECT PESTS
North Central Agricultural Research Laboratory
2010 Annual Report
1a.Objectives (from AD-416)
The objective of this seed grant proposal is to develop a two stage risk assessment tool. The outcome anticipated is a prototype risk assessment model that provides reliable forecasting capabilities for estimating the risk from a specific arthropod becoming established in corn production areas in South Dakota at the county level. The risk assessment will be based on county characteristics favorable to establishment of high consequence arthropods in a specific South Dakota county.
1b.Approach (from AD-416)
A two stage model is proposed. The first stage of the model will generate ordinal quantitative risk assessment estimates for arthropod establishment-risk based on county characteristics using a “scorecard qualitative assessment approach.” The second stage generates a probability estimate (a cardinal measure) for an arthropod of high economic consequence becoming established in a South Dakota county, based on the first stage risk assessment rankings. We intend to collect data on: a) county attributes associated with risk establishment, and b) county level arthropod infestation data based on standardized sampling procedures targeting seven herbivorous pests that represent different taxonomic and feeding guilds consistently problematic for conventional corn fields in South Dakota. The data will be used to calibrate the two-stage model.
The first stage of the two-stage model will be designed in accordance with the methodology developed in the country risk analysis literature. The country risk analysis methodology will be modified to provide qualitative risk rankings for county attributes correlated with successful pest establishment. The second stage will develop a logistic regression model that will relate the incidence of successful establishment in a county (sample data) to variables expected to influence the likelihood of successful establishment (county risk attributes).
Our proposed high consequence corn infesting arthropod risk assessment project overcomes two flaws identified in the non-indigenous species (NIS) risk assessment literature:.
1)our proposed county level risk assessment model provides cardinal rankings rather than ordinal rankings and thus provides a probability ranking for pest establishment risk; and.
2)our proposed model focuses on only the establishment stage of invasion at the county level.
The objective of this project is to develop a two-stage risk assessment model that can forecast the risk from a specific insect becoming established in corn production areas in South Dakota. In 2010, we collected data on county-level insect infestations based on standardized sampling procedures targeting seven herbivorous pests that represent different taxonomic and feeding guilds consistently problematic for conventional corn fields in South Dakota. We also now have a much better understanding of what insects are present in SD cornfields for use in assessing future pest management needs. These data will be used to calibrate a two-stage mathematical model that will incorporate county-level crop production, environmental, and sociological data into the levels of pest infestation intensities during the winter of 2010-11.