Fall armyworm. Picture: SUPPLIED
Fall armyworm. Picture: SUPPLIED

Beijing — Scientists in China are seeking to deploy an army of predatory stink bugs to battle a fall armyworm incursion that threatens to devastate the country’s grain crops.

The insect, Arma chinensis, is a natural enemy of fall armyworm, according to the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences. Researchers there believe it may be a useful biological agent to control the crop-ravaging caterpillar, which arrived in China early in 2019 after spreading from the Americas to Africa and across parts of southern Asia.

The stink bug’s killing powers are impressive. A mature nymph can exterminate as many as 41 fall armyworm larvae a day by anesthetising and paralysing the pest, and sucking out body fluid, causing fatal damage to internal organs, Chinese scientists found during a field trial in the southwestern province of Yunnan.

The fall armyworm has affected crops in 18 provinces and is predicted to reach China’s corn belt in the northeast of the country in June. There is a “high probability” that the pest will spread to the entire country’s grain-producing area in the next year, the US department of agriculture said on May 29.

The Institute of Plant Protection has set up a “factory” that can breed 10-million stink bugs a year to sustainably manage the pest without heavy reliance on pesticides.

The stink bug is widely distributed in China and is usually found on elm and poplar trees, and in cotton and soybean fields, the institute’s researchers said in a 2012 paper.

The insect preys on a large variety of species, including cotton boll-worm, and can effectively suppress agricultural and forest pests in the orders Lepidoptera, Coleoptera, Hymenoptera and Hemiptera, scientists said in an April 2013 paper.