Chinese Journal of Entomology (1990) 10, 301-324

C.H. Cheng and J.L. Lu (1990)
Detection of the trans-oceanic immigration of rice planthoppers, Nilaparvata lugens Stal and Sogatella furcifera Horvath to the southwestern Taiwan and their relative weather-conditions
Chinese Journal of Entomology 10 (3), 301-324
Abstract: The brown planthopper (Nilaparvata lugens Stal) and white backed planthopper (Sogatella furcifera Harváth) are important pest insects of rice in Taiwan. It is known that some of the planthoppers are able to overwinter on the island, while the other individuals immigrate from overseas every year. The present study was aimed at detecting the fact of the immigration of the planthoppers into southwestern Taiwan. Analysis of the data collected with an air-borne net trap, suction light trap, yellow water-pan trap and field survery from 1985 to 1989 revealed that the immigration of planthoppers occurred from April to August with a peak in the period from mid-June to the end of July. In general, each immigration wave lasted for 2 to 4 days, but the frequence of immigration varied greatly among years depending on the meteorological condi-tions. Thus, the total number of the planthoppers caught by the traps differed markably. The maximum catches were 25 and 73 times of the minimum for the air-borne net trap and suction light trap, respectively. The air-borne net trap was more effective for distinguishing the waves in the year of mass immigration, while the suction light trap was more reliable in detection of minor immigartion. Therefore, the combined use of the air-borne net trap and suction light trap was the most adequated for estimating the time, waves and density of immigrations. Analysis of meteorological factors and the immigration of plantopper to south-western Taiwan showed that the associated weather conditions might be divided into frontal type, depression circulation type (including tropical storm, tropical depression, mobile depression and depression zone), southwestern airflow type and subtropical-height circulation type. In addition, it was also recognized that distinct immigration was often associated with the following meteorological characterestics: 1) On the 850 mb weather chart: the southwestern to northwestern air-flows with an averaged speed more than 9km/hr was prevalent in southern China and Taiwan, or a southern to southeastern airflows extended from northern Luzon to the west coast of Taiwan, when temperature was over 17°C; 2) On the surface weather charts in Chaiyi: rainy, and the southeastern to northwest winds at a maximum speed more than 19 km/hr blew for several hours, and temperature was over 22°C.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Nilaparvata lugens	Rice (Oryza)	Taiwan