การคาดการณ์การระบาดของเพลี้ยกระโดดสีน้ำตาลจากกับดักแสงไฟ

Abstract

Light trap is an effective tool for monitoring the outbreaks in hot spot areas. The light traps were set in 7 Rice Research Center(RRC) incorporated with sampling in farmer's fields at hot spot areas of BPH. This research was conducted at Chai Nat(CNT), RRC Pathum Thani(PTT)-RRC, Prachinburi(PCR)-RRC, Phitsanulok(PSL)-RRC, Ratchaburi(RBR)- RRC, Phra Nakhon Si Ayutthaya(AYY)-RRC, Phatthalung(PTL)-RRC and Nakhon Si Thammarat (NSR)-RRC during October 2006 to September 2007. Light trap were set near experimental fields of RRC and collected insects during 6.00-9.00 pm everyday through out the year. The results showed that light trap at CNT-RRC, PSL-RRC, PRC-RRC could collected huge number of the BPH . The peak of BPH in light trap at CNT-RRC was more than 170,000 insects per month which related to the BPH outbreak in farmer's fields. This peak could use as index for forecasting outbreak in virulent areas in Chai Nat province and nearby. Factors inducing severely outbreak were rice varieties and number of immigrant mirid bug at that time, the resistant variety showed less outbreak evidence than susceptible variety. The number of BPH around 40,000-70,000 insects per month was the indicator for BPH outbreak warning to the farmers to take insect survey in their field. Whereas the number of BPH about 100-1,000 insects/month indicate less chance of outbreak occurrence. The peak of BPH from light trap setting at CNT-RRC and PCR-RRC trended to relate with number of BPH in the field at 15-20 days after seeding .