The beet armyworm (Spodoptera exigua) is a pest widely distributed across the world, inhabiting temperate and subtropical regions. It particularly prefers warm and dry climates and causes severe damage in Asia, including Korea, as well as in North America. With the expansion of international trade and logistics, infestations are increasingly being reported in new climate zones.
The beet armyworm is a highly polyphagous pest, attacking over 200 different crops. Major hosts include vegetables, beans, ornamentals, and cotton, where it causes significant damage. Depending on the temperature and region, it can produce 5–7 or more generations per year. After hatching, larvae actively feed on crops for 2–3 weeks before pupating and then emerging as adults to repeat the cycle. The larval stage is the most destructive: early instar larvae (1st–2nd instars) feed in groups on the undersides of leaves, scraping away the tissue and leaving only the epidermis, resulting in whitish damage (leaf “skeletonization”). As larvae grow (3rd instar and beyond), they consume entire leaves or bore into fruits and stems, causing much more serious injury. If not controlled at this stage, crop growth is severely hindered, and yields drop drastically.
The beet armyworm is notorious for developing resistance to chemical pesticides. Repeated use of the same pesticide quickly becomes ineffective, and cross-resistance to new chemicals often develops as well. Its rapid reproduction and high fecundity mean that missing the control window leads to explosive population increases. Since adults are nocturnal while larvae hide during the day on leaf undersides or inside plant tissues, pesticides often fail to reach them effectively. With its wide range of host crops, infestations also spread rapidly.
Multinational pesticide companies are racing to develop microbial pesticides against this pest, but most of these products remain expensive, narrow in spectrum, and only partially effective. By contrast, the JADAM Microbial Pesticide (JMP), invented by Dr. Youngsang Cho, offers a groundbreaking alternative that overcomes all of these shortcomings.
This video demonstrates the control of beet armyworm with JMP—one of the most difficult pests to manage. JMP can be easily self-manufactured by farmers using inexpensive materials, yet it delivers powerful, broad-spectrum pest control. It empowers farmers to take pest management into their own hands while opening a new path forward for organic farming worldwide.