Dozens of hectares of cultivated rice fields in Takeo province have been destroyed after the crops were overrun by brown planthoppers, a native insect species that infests paddies when its natural predators are killed off due to chemical spray or dry weather conditions.
To counter the brown planthopper threat, Takeo Provincial Governor Sou Phirin said he has urged farmers to limit the use of chemicals in their paddies and instead rely on natural predators, which are usually enough to keep the planthopper population at non-damaging levels.
“We have been encouraging local farmers to use useful bugs to kill the pests,” Sou Phirin said Tuesday.
Massive outbreaks of the brown planthopper usually follow after the application of insecticide, which lowers the insect’s natural enemy populations.
And since many of the predators of the brown planthopper are semi-aquatic, dry weather in Takeo has helped the pest to spread unchecked.
The brown planthopper kills rice crops by sucking out sap from the plants and is usually preyed upon by predators such as hunting spiders that are often found near the surface of the paddy water, where the planthopper likes to feeds.
The UN Food and Agriculture Organization states that the release of fungicides originally developed to control brown planthopper populations are also highly toxic to the pest’s natural enemies such as spiders.
Rather than reduce the pests’ number, the fungicides resulted in high populations of brown planthoppers in paddies.
Hean Vanhorn, deputy director of the Ministry of Agriculture’s Agronomy and Land Quality Improvement Department, downplayed any substantial threat to this year’s rice crop.
Hean Vanhorn said the planthopper pales in comparison to infestations of the golden apple snail, an invasive species that remains a serious concern to rice farmers in Kampot and Svay Rieng provinces.
“And now this [snail] has stormed the Kirivong district in Takeo province,” he said.
