| Publication date | July 22, 2020 |
|---|---|
| Sector | Natural ecosystems |
| Region name | Chubu（Mie Prefecture） |
Nezara viridula are insects that live in tropical to subtropical regions and are usually considered pests that damage cereal grain. In Mie Prefecture, they were found only in the Higashi-kishu region until the 1980s, however the potential overwintering area has expanded due to global warming, and distribution is now confirmed to have extended to the Ise plain from around 2006.
Nezara viridula feeds on different plants according to generation, such as wheat for the overwintering generation, young rice for the second generation, and soybeans for the third generation. The Mie Prefecture Agricultural Research Institute used this behavior to investigate the distribution of the species (Fig. 1).
Based on this research, a predictive model of possible wintering areas was created based on the number of days with an average daily temperature of less than 2.5℃ (December 1 - February 28) obtained from Agro-Meteorological Grid Square Data, NARO (see Note 1), and data from the Mie Prefectural Plant Protection Office showing the occurrence of Nezara viridula in soybeans in October (prefectural average of the number of adult larvae per 25 strains). The predictive model uses the Agro-Meteorological Grid Square Data to calculate the overwintering probability for any given area, divided into a grid of 1 km2, for which a prediction is required. It is also possible to create an overwintering area forecast map (Fig. 2). The results of the predictive model were compared with distribution data of the overwinter generation and wheat. It was consequently found that the accuracy of the predictive model compared with the distribution of overwintering generations observed in Mie Prefecture in 2015 was approximately 70% or higher (see Note 2).
It is expected that the prediction of possible overwintering areas of Nezara viridula can be used as forecasting information for pest control for rice, soybean, and other crops.
Footnote
(Note 1) Research and development by the National Agriculture and Food Research Organization. https://amu.rd.naro.go.jp/
(Note 2) Areas with a probability of 0.5 or more are defined as areas with overwintering potential.
Red: Prescence of Nezara viridula confirmed. White: No Nezara viridula observed
Fig. 1 Nezara viridula distribution data for overwintering generation in wheat crop, and third generation in soybean for both 2012 and 2014.
(Source: Mie Prefectural Agricultural Research Institute, "Nezara viridula can overwinter and settle in most agricultural areas in Mie Prefecture")
Fig. 2 Prediction of Overwintering Areas in 2015, Prepared Using the Prediction Program
(Source: Mie Prefecture Agricultural Research Institute "Development of Overwintering Possible Area Prediction Technique for Nezara viridula")
