The Influence of Sogatella furcifera (Hemiptera: Delphacidae) Migratory Events on the Southern Rice Black-Streaked Dwarf Virus Epidemics

Abstract

Southern rice black-streaked dwarf virus (SRBSDV) caused serious rice losses. After the first outbreak in 2009 in northern Vietnam and southern China, the virus ravaged crops again on enormous scales in 2010, but infections have decreased sharply since 2011. We presumed that the sudden epidemics and fadeout of SRBSDV would be closely related to the migratory events of the insect vector, Sogatella furcifera. This study sought the source area of SRBSDV using the trajectory analysis method, and revealed the relationship between SRBSDV dynamics and migration of S. furcifera populations via an in-depth analysis of meteorological background of S. furcifera migration fields. The results showed that Northern Vietnam was the direct virus source area of the SRBSDV infection in China, and South Central Coast of Vietnam was the original source area of SRBSDV. Southwesterly winds were prevalent in spring of 2010 and carried large numbers of viruliferous S. furcifera to China from northern Vietnam. This infestation of S. furcifera was the direct cause of the SRBSDV outbreak in China in 2010. In 2011, the winter-spring temperatures were abnormally low and southeasterly and easterly winds dominated; therefore, the number of viruliferous S. furcifera that entered China was small, and consequently, the occurrence area of SRBSDV was rapidly reduced. The return of viruliferous S. furcifera to South Central Coast of Vietnam was an important factor that affected the occurrence scale of SRBSDV in the following year.

Migration patterns and winter population dynamics of rice planthoppers in Indochina: New perspectives from field surveys and atmospheric trajectories

“…1) makes it ideally placed to receive large numbers of return migrants from southern China, and it lies to the south of the northern winter-breeding limit (around the Tropic of Cancer; Cheng, 1979;Luo et al, 2013). However, field surveys conducted as part of this study (Plates S1-S5) in NCV confirmed that there is a 3-month fallow period during November to January when no rice crops are grown, as previously reported (Wu et al, 2017), and rice at a suitable developmental stage for RPH colonization is not present until late-February at the earliest. As rice is the only food source of RPH, the absence of suitable hosts will disrupt the population cycle leading to an apparent gap in the migration loop.…”

“…Thus the large populations which outbreak in southern and eastern China each summer (Hu et al, 2011(Hu et al, , 2018Lu et al, 2017) must return to Indochina during the autumn in order for the migratory populations to persist. Direct evidence for these southward return migrations was relatively scant until recently, and limited to a few observations of movements within China (Riley et al, 1991;Hu et al, 2013), but the current paper and recent work of Wu et al (2017) indicate that wind conditions suitable for transport from southern China to Indochina are frequent in the autumn. In particular, we identify the NCV region as a key area for the return migrants, with a high proportion of trajectories from the southern Chinese provinces of Guangdong, Guangxi, and especially Hainan, reaching NCV (Fig.…”

“…The annual migration is generally believed to take the form of a closed loop, but in contrast to the wellstudied spring migrations to the north, the autumn return movements and over-wintering dynamics within Indochina are poorly known. There is some evidence of southward autumn migrations within China (Riley et al, 1991;Hu et al, 2013), but while the ultimate destination of these return migrants is often considered to be the Indochina Peninsula (Hu et al, 2013(Hu et al, , 2018Wu et al, 2017), the precise destination of the autumn return migrants, and the regions where they persist throughout the winter, remain poorly understood.…”

“…Recent work has identified the north-central Vietnam region (NCV; Fig. 1) as potentially a key area, as it appears to be the principal source of migrants colonizing southern China each spring (Hu et al, 2017;Wu et al, 2018b), and it is an important destination for returning migrants from southern China during autumn (Wu et al, 2017). This poses the question of whether the NCV region forms part of the main overwintering area, as its geographical location (Fig.…”

Characterization of the Akirin Gene and Its Role in the NF-κB Signaling Pathway of Sogatella furcifera

“…S. furcifera can migrate over long distances in temperate and tropical regions of Asia and primarily feeds on rice plants ( Shen et al, 2005 ; Ma et al, 2017 ), from which it sucks sap, causing yellowing, stunting, and hopper burn, and finally plant death ( Wang et al, 2017 ). More importantly, S. furcifera can transmit dangerous rice viruses, further contributing to the damage of rice plants ( Zhou et al, 2013 ; He et al, 2016 ; Wu et al, 2017 ). Therefore, it is important to investigate the immune mechanisms of S. furcifera to develop effective control strategies.…”