Source: National Agricultural Technology Extension Service Center
Based on comprehensive analysis of current pest population bases, rice variety resistance, cultivation practices and meteorological conditions, it is projected that early rice pests and diseases will occur at a moderate level nationwide this year, covering a cumulative area of 265 million mu. Specifically, striped stem borer will break out severely in rice-growing regions south of the Yangtze and in the middle-lower reaches of the Yangtze River; rice planthoppers will occur moderately severe in South China rice areas, and sheath blight will hit moderately severe levels in central-western South China and regions south of the Yangtze River. Diseases and pests including rice leaf roller and rice blast will develop from slightly light to moderate levels.
1 Outbreak Trends
• Striped Stem Borer: Severe outbreaks in rice areas south of the Yangtze and the middle-lower Yangtze reaches, moderate occurrence in South China rice regions, slightly light occurrence in southern Southwest rice areas, with a national cumulative affected area of 59 million mu.
• Rice Planthoppers: Moderately severe occurrence in South China rice areas, moderate in southern Southwest and regions south of the Yangtze River, slightly light in the middle-lower Yangtze reaches, covering a cumulative national area of 62 million mu.
• Rice Leaf Roller: Moderate occurrence in South China and rice areas south of the Yangtze River, slightly light in southern Southwest and the middle-lower Yangtze reaches, with a cumulative national affected area of 51 million mu.
• Sheath Blight: Moderately severe outbreaks in central-western South China and rice areas south of the Yangtze River, moderate in eastern South China and the middle-lower Yangtze reaches, covering a cumulative national area of 63 million mu.
• Rice Blast: Moderate occurrence across South China, regions south of the Yangtze River and the middle-lower Yangtze reaches, yet high severe outbreak risks exist on susceptible varieties, with a cumulative national affected area of 15 million mu.
• Other Pests and Diseases: Rice false smut, southern rice black-streaked dwarf virus disease, yellow stem borer, small brown planthopper and other pests/diseases occur to varying extents in partial rice-growing zones, covering a cumulative national area of 15 million mu.
2 Forecasting Basis
2.1 Most Pests and Diseases Have Moderate to High Initial Population Bases
(1) Striped Stem Borer
At present, populations in South China rice areas are mainly in the emergence stage of the 1st generation to larval damage stage of the 2nd generation; those south of the Yangtze River are in the peak larval damage period of the 1st generation; populations in the middle-lower Yangtze reaches are in the emergence stage of overwintering generation to larval damage stage of the 1st generation.
Regions south of the Yangtze River suffer severe infestations: the average larval count per mu in fields of Hunan and Jiangxi stands at 2,000–2,500 heads, a year-on-year drop of 10%–20%. Local areas including southern and central Hunan, central and northern Jiangxi record 5,000–30,000 larvae per mu, with the rate of damaged leaf sheaths generally at 1%–2%.
Infestation remains slightly light overall in South China and the middle-lower Yangtze reaches, with average field larval counts below 300 heads per mu. Individual plots in northeastern Guangxi, northeastern Guangdong and northwestern Fujian see 5,000–7,000 larvae per mu, and the damaged leaf sheath rate is generally under 1%.
(2) Rice Planthoppers
Immigration peaks have emerged successively in southern Southwest, South China and regions south of the Yangtze River since April. As of May 20, cumulative trap catches by light traps across provinces are as follows: Yunnan 30,000 heads, Hainan 11,000 heads, Guangxi 53,000 heads, down 19%, 56% and 35% year-on-year respectively; Guangdong 59,000 heads, Fujian 9,000 heads, Jiangxi 10,000 heads, surging 2.1 times, 67% and 3.6 times year-on-year respectively. More than 1,000 planthoppers were trapped per single light trap in a single day at 11 monitoring sites covering southern Yunnan, southern and northern Guangxi, western Guangdong, southern Fujian and southern Hunan.
Driven by early immigration and continuous rainfall, the number of planthoppers per 100 rice clumps rose 18%–94% year-on-year. After prevention and control measures, the count per 100 clumps is generally kept below 400 heads.
(3) Rice Leaf Roller
Moth immigration peaks appeared at light traps in central-western South China starting in May. By May 20, cumulative moth trap catches by provincial light traps reached 4,000 heads in Guangxi and 14,000 heads in Guangdong, up 1.4 times and 4.1 times year-on-year. Over 100 moths were captured per single light trap daily at six monitoring sites in central Guangxi and western Guangdong in early and mid-May.
Currently, moth counts per mu in South China rice fields average 400–500 heads, more than doubling year-on-year. Local zones in southern and central Guangxi, western Guangdong record 1,000–3,000 moths per mu, with a maximum of 10,000–12,000 heads. The larval count per 100 clumps averages 7–8 heads, down roughly 10% year-on-year, while individual untreated plots in southern and central Guangxi and western Guangdong see 150–200 larvae per 100 clumps.
(4) Sheath Blight & Rice Blast
Ample pathogen inoculum exists in rice fields, triggering moderately severe outbreaks on susceptible varieties in partial regions.
For sheath blight, the diseased clump rate generally hits 1%–8% in South China and rice areas south of the Yangtze River, yet early-transplanted low-lying waterlogged fields in southern Guangxi and western Guangdong register a peak diseased clump rate of 80%–85%.
The diseased leaf rate of rice blast stays below 0.5% in most areas, but susceptible varieties in partial zones of Guangxi and Guangdong show a diseased leaf rate of 20%–25%.
(5) Southern Rice Black-Streaked Dwarf Virus Disease
Sporadic occurrences are reported in Guangdong and Fujian. Tests show the virus-carrying rate of white-backed planthoppers in early spring is generally lower than 0.1%.
2.2 Weak Variety Resistance, Favorable Cultivation Conditions and Rising Pesticide Resistance Increase Severe Epidemic Risks
This year, several high-quality high-yield early rice varieties have declined resistance to rice blast, bringing high risks of rice blast epidemics. Widespread bridge fields and scattered intercropped plots across all regions facilitate repeated infestation by pests. Dense rice planting and heavy fertilization create closed canopy microclimates with moderate temperature and high humidity in fields, which favor the reproduction and spread of pests and diseases.
According to the 2025 Rice Pest Pesticide Resistance Monitoring Report, striped stem borer populations in monitored areas have developed moderate to high resistance to chlorantraniliprole, abamectin and emamectin benzoate. Zones with high resistance to chlorantraniliprole have further expanded from double-cropping rice regions including Zhejiang, Jiangxi and Hunan to single-cropping rice areas such as Anhui and Hubei.
Brown planthopper populations exhibit high-level resistance to imidacloprid, thiamethoxam, buprofezin and pymetrozine; white-backed planthopper populations have moderate to high resistance to buprofezin; rice leaf roller populations show moderate to high resistance to chlorantraniliprole.
All major rice-producing regions shall carry out targeted technical guidance on rotational pesticide application based on local conditions, improve control efficacy against major pests and diseases, and fully guarantee higher per-unit yield of rice on large-scale farmlands.
2.3 Meteorological Conditions Favor Pest and Disease Outbreaks and Spread
Forecasts from the National Meteorological Center indicate temperatures in major early rice-producing regions across China in June will range from close to average to above average. Precipitation in most of South China, regions south of the Yangtze River and southern Southwest China will be near or above normal levels.
In addition, the number of typhoons landing in China in summer will exceed the average, with generally stronger intensity, mainly impacting coastal areas of East China and South China.
Collectively, these climatic conditions facilitate migration and colonization of the two migratory rice pests, reproduction and damage of striped stem borer, as well as the development and spread of diseases including rice blast.
