By Fang Lin on Monday, 3 March 2014 in Agrochemical News

China National Agricultural Technology Extension and Service Center (NATESC) released results of a study investigating brown rice planthopper’s resistance to Buprofenzin. The study revealed that the insect has developed “high” or "extremely high” resistance to Buprofenzin. NATESC also advised that the insecticide may no longer be suitable for protecting rice against brown planthopper.

Last year, the NATEC cooperated with several agricultural universities and crop protection stations to study the resistance of brown rice planthopper to buprofenzin in 26 test sites in 10 provincial regions. The results showed high levels of resistance in all test sites. The NATEC then conducted field trials in county regions in Jiangsu, Anhui, Jiangxi and Guangxi. Five days after application, the control effect ranged from 40-61% and the effect reduced to 31% - 63.3% in another five days.

With a control effect below 65%, the NATEC suggest that rice planting provinces should stop using buprofenzin for brown planthopper control. Instead, rotation of alternates such as pymetrozine and nitenpyram is preferable.

Buprofenzin was included as the active substance in Annex 1 of the EU’s Council Directive 91/414/EEC on 21 January 2011. This means that the insecticide is available in EU markets. Chinese regulations have a stipulation where the use of a pesticide is contingent on its effectiveness. One of the preconditions for issuing a restriction is based on pesticide resistance. If NATEC’s suggestion and study reports are accepted by the agricultural administrative authorities, the insecticide will be restricted in some provinces.