nature biotechnology advance online publication l e t t e r sThe brown planthopper (BPH) is the most destructive pest of rice (Oryza sativa) and a substantial threat to rice production, causing losses of billions of dollars annually 1,2 . Breeding of resistant cultivars is currently hampered by the rapid breakdown of BPH resistance 2 . Thus, there is an urgent need to identify more effective BPH-resistance genes. Here, we report molecular cloning and characterization of Bph3, a locus in rice identified more than 30 years ago that confers resistance to BPH. We show that Bph3 is a cluster of three genes encoding plasma membrane-localized lectin receptor kinases (OsLecRK1-OsLecRK3). Introgression of Bph3 into susceptible rice varieties by transgenic or marker-assisted selection strategies significantly enhanced resistance to both the BPH and the white back planthopper. Our results suggest that these lectin receptor kinase genes function together to confer broad-spectrum and durable insect resistance and provide a resource for molecular breeding of insect-resistant rice cultivars.BPH (Nilaparvata lugens Stål, Hemiptera, Delphacidae) is a monophagous, phloem-sucking herbivore. It sucks the sap from the rice phloem using its stylet, and causes direct damage to rice plants. BPH can also cause indirect damage to rice plants through the transmission of viruses including the rice ragged stunt virus and grassy stunt virus 2 . Repeated overapplication of pesticides for BPH management has heavily polluted the environment 3 . Breeding of resistant cultivars is the most cost-effective and environmentally responsible strategy for BPH management but developing insect resistant cultivars by traditional breeding approaches is extremely difficult and time consuming owing to a paucity of knowledge about BPH resistance genes and germplasm.To date, 28 BPH resistance loci have been identified from cultivated and wild species of Oryza 2,4,5 . Only two of these resistance genes, Bph14 and Bph26 have been cloned to date 6,7 . In addition, BPH resistance of IR26 and IR36, two widely cultivated rice varieties that harbor the BPH resistance loci Bph1 and bph2, respectively, was quickly broken down in just a few years owing to the rapid adaptation of the BPH 8 . Thus, there is still an urgent need to identify new types of resistance genes and germplasm for developing efficient approaches to breed broad-spectrum and durable BPH-resistant rice cultivars. Notably, the Bph3 locus, originally identified in the Sri Lankan indica cultivar Rathu Heenati 9 , displayed resistance to four BPH biotypes (BPH biotypes refer to specific populations of BPH classified according to their virulence on different BPH resistance genes) 2,10 . Furthermore, rice varieties harboring Bph3 deployed more than 30 years ago in the Philippines are still resistant to BPH 8 . However, the molecular basis of this broad-spectrum and durable resistance of Bph3 against BPH remains unknown.We observed that Bph3-containing Rathu Heenati infested with BPH of mixed biotypes (biotype ...

Abstract. A case study is presented of the autumn migration of the brown planthopper, Nilaparvata lugens (Stål), in the area of Nanjing in the People's Republic of China. The study was made using a high frequency (8 mm wavelength) radar and a net suspended from a kytoon. The observations confirmed that long‐distance return migrations occur in China in mid and late September, with N.lugens being carried on the prevailing north‐easterly wind towards the autumn infestation and overwintering areas of the species. After mass take‐off in the late afternoon or at dusk, the migrants flew for several hours during the evening, often in a dense layer which formed at heights between about 400 and 1000m above ground. These layers often had well‐defined ceilings corresponding to an air temperature of about 16°C. The migration height was above the top of the surface temperature inversion, i.e. the migrants did not fly at the height of the warmest air. The dense layer concentrations overflying the radar were backtracked to source areas up to 240 km away in the north‐east of Jiangsu Province. Planthoppers observed emigrating from the Nanjing area would reach areas in south Anhui Province or north Jiangxi Province if they flew for 12 h. There was a second period of mass take‐off at dawn. Insect layers sometimes formed but did not last longer than 1–2h. The present results were strikingly different from those previously observed in the dry season in the Philippines, where migratory flight durations were largely confined to periods of about 30min at dusk and dawn. Our observations are discussed in relation to the equator‐wards return migrations undertaken in autumn by other insect species, and the importance of these migrations for the maintenance of long‐flying genotypes in the overwintering populations is considered.

[1] Intraseasonal variability (ISV) of sea surface height (SSH) over the Bay of Bengal (BoB) is studied using altimetry data and an eddy-resolving ocean model. In both the model hindcast and satellite observations, large SSH ISV is found along the eastern and northern coasts of the BoB, in the western BoB, and in a zonal band across the Bay centered near 5 N. The ISV displays a clear seasonality. In the western BoB, it reaches its annual maximum in spring, whereas it does so in summer and autumn southeast of Sri Lanka. Driven by equatorial intraseasonal winds, equatorial Kelvin waves propagate eastward, reach the western coast of Sumatra, and reflect there to propagate around the perimeter of the BoB as coastally trapped waves. Two distinct bands of high eddy activity are detected in the western and central BoB, respectively. In both bands, isolated eddies propagate southwestward. Eddy formation in the eddy train in the central Bay is linked to the coastal wave as it bends around the corner of the Irrawaddy Delta off Myanmar. Eddy activity contributes to the high ISV in the central Bay to some extent. An energetics analysis indicates that high total eddy energy in the western BoB is due to barotropic/ baroclinic instability of the mean current.