Changing patterns of the East Asian monsoon drive shifts in migration and abundance of a globally important rice pest.

Numerous insects including pests and beneficial species undertake windborne migrations over hundreds of kilometers. In East Asia, climate-induced changes in large-scale atmospheric circulation systems are affecting wind-fields and precipitation zones and these, in turn, are changing migration patterns. We examined the consequences in a serious rice pest, the brown planthopper (BPH, Nilaparvata lugens) in East China. BPH cannot overwinter in temperate East Asia, and infestations there are initiated by several waves of windborne spring or summer migrants originating from tropical areas in Indochina. The East Asian summer monsoon, characterized by abundant rainfall and southerly winds, is of critical importance for these northward movements. We analyzed a 42-year dataset of meteorological parameters and catches of BPH from a standardized network of 341 light-traps in South and East China. We show that south of the Yangtze River during summer, southwesterly winds have weakened and rainfall increased, while the summer precipitation has decreased further north on the Jianghuai Plain. Together, these changes have resulted in shorter migratory journeys for BPH leaving South China. As a result, pest outbreaks of BPH in the key rice-growing area of the Lower Yangtze River Valley (LYRV) have declined since 2001. We show that these changes to the East Asian summer monsoon weather parameters are driven by shifts in the position and intensity of the Western Pacific subtropical high (WPSH) system that have occurred during the last 20 years. As a result, the relationship between WPSH intensity and BPH immigration that was previously used to predict the size of the immigration to the LYRV has now broken down. Our results demonstrate that migration patterns of a serious rice pest have shifted in response to the climate-induced changes in precipitation and wind pattern, with significant consequences for the population management of migratory pests.

Decline of three farmland pest species in rapidly urbanizing landscapes.

Urbanization is a pressing challenge for earth's humans because it is changing not only natural environments but also agricultural lands. Yet, the consequences of cropland loss on pest insect populations that largely depend on these habitats remain largely unclear. We used a 17-year data set to investigate the dynamics of three moth pest species (i.e., striped stem borer, yellow stem borer, and pink stem borer) and their driving forces across the largest mega-urban region of China. Total abundance of three pest species is declined by about 80%, which was strongly associated with cropland loss during rapid urbanization. Our findings indicate that not only the increasing conversion of natural areas to human-dominated landscapes but also that of agricultural lands to urban landscapes can be critical to insect populations. It is therefore essential to monitor and understand the insect dynamics in rapidly urbanizing regions, which are currently found in many developing countries worldwide.

An Alternative Method of Endoscopic Intrasphenoidal Vidian Neurectomy.

OBJECTIVE: To develop an easy surgical approach to facilitate clinical management. STUDY DESIGN: A novel transnasal endoscopic 3-step surgical method for vidian neurectomy was designed and tried in 91 cases with a mild-to-severe degree of allergic and nonallergic rhinitis refractory to routine medical therapy. SETTING: Endoscopic vidian neurectomy requires accurate localization of the vidian canal. However, it is not easy to localize during surgery because of its deep location and the complex anatomy of the pterygopalatine fossa. SUBJECTS AND METHODS: This technique consists of 3 steps, including transnasal endoscopic perforation of the anterior wall of the sphenoidal sinus as the first step and removal of the anterior wall until the exposure of the vidian canal in the junction between the anterior wall and the floor of the sphenoid sinus as the second step. The last step is the accurate resection and cauterization of the vidian nerve. In some cases in which the sphenoid sinus developed well with a big lateral space, an extended procedure of posterior ethmoidectomy was included to allow good exposure of the vidian canal. RESULTS: Using this technique, successful endoscopic vidian neurectomy in this series of patients was confirmed by both histology and Schirmer test, showing its distinct advantages of easy localization of the vidian canal and less risk of injury to the nerve and vessel bundles within the pterygopalatine fossa. CONCLUSION: Taken together, this novel 3-step procedure of endoscopic vidian neurectomy plus an extended procedure guarantees good exposure of the vidian canal and therefore accurate vidian neurectomy.