Population Increase of Brown Planthopper (Nilapavata iugen Sta°l) on Photoperiod Insentitive Certified Rice Varieties

Abstract

Increase population of the brown plant hopper (BPH, Nilaparvata lugen (Sta˚l)) trials were carried out in the green house at Prachinburi Rice Research Center in 2002 and 2003. The objective was to study the increase population of BPH fed on photoperiod insensitive rice varieties. Two conditions were studied (1) BOH population increased from ten 2-days old nymphs/pot (2) BPH population increased from 1 pair of gravid female and male/pot. Three photoperiod insensitive certified rice varieties namely Khno Jao Hawm Klawng Luang 1, Khao Jao Hawm Suphanburi and Pathumthani 1 were studied with Suphanburi 90 and RD 7 as a resistant and susceptible check respectively. As BPH was increased from ten 2-days old nymph, numbers of the first generation of the BPH nymphs on Khao Jao Hawm Klawng Luang 1 and Pathumthani 1 were higher than nymphs on Suphanburi 90. However, the number of the second generation nymphs on Suphanburi 90 was higher than nymphs on Khao Jao Hawm Klayang Luang 1 and Pathumthani 1. Population increase of BPH started from 1 pair of male and female, the first and second generation nymphs of BPH reared on Khao Jao Hawm Klawng Lugang 1 was the highest. The numbers of nymphs on Khao Jao Hawm Klawng Luang 1 and RD 7 were higher than nymphs on Suphanburi 90. Nymphal period of BPH reared on Duphanburi 90 was the shortest at 17.7 days, and nymphs reared on Khao Jao Hawm Suphanburi was the longest at 18.9 days. Nymphal period of BPH reared on Khao Jao Hawm Klawng Luang 1 and Pathumthani 1 were 18.3 and 18.4 days respectively.