Biotype Diversity of Brown Planthopper in Lower Northern Thailand

Abstract

The brown planthopper, Nilaparvata lugens (Stål), is one of the most important insect pests of rice in Asia which adapts very well to be many biotypes living in the same rice field environment. Therefore, the diversity of brown planthopper biotypes in lower northern Thailand was conducted. Population of brown planthopper was collected from the rice paddy field in 4 provinces of lower northern Thailand: Phitsanulok (PHS), Tak (TK), Uttaradit (UT) and 2 parts of Phetchabun (Lomsak, LK and Srithep, ST). Biotype of brown planthopper was classified by using standard rice varieties and indices based on standard evaluation system for rice from international rice research institute (IRRI). The result revealed that brown planthopper in lower northern Thailand could be classified into 2 main groups. First group, reported biotypes, was biotype 2, 3 and 4. Second group, unidentified biotypes, was UKPHS1, UKTK1, UKTK2, UKUT1, UKLS1, and UKST1. All biotypes in unidentified group were closely related to biotype 4.