Variation of pre-ovipositional period in the brown planthopper, Nilaparvata lugens, collected in tropical, subtropical and temperate Asia

Abstract:  We investigated the pre-ovipositional period of Nilaparvata lugens originating from tropical, subtropical and temperate regions of East and Southeast Asia using laboratory experiments to compare the migration capability of the populations. Macropter females collected in 1992 from Japan and subtropical North Vietnam had a longer immature period than those from tropical Indochina Peninsula, i.e. the day of the first oviposition after eclosion was about 3 days later in the former populations. Populations collected in 1993 and 1994 from Japan, Central and South China, and North Vietnam also had a longer immature period than that of the tropical Malaysian population. Thus, a general trend was demonstrated that macropters originating in temperate and subtropical East Asia had a longer pre-ovipositional period, which is presumably beneficial for pre-reproductive long-distance migration. This finding supports a current hypothesis for the migration system of N. lugens existing in East Asia, which has maintained the capability of long-distance migration throughout years in spite of the disadvantage of prolonged oviposition for multiplication.