Bean bug - JADAM Organic Farming

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bean bug adult

Bean bug
Hemiptera, Alydidae

○ Scientific name: Riptortus clavatus (Thunberg)
○ Size: the length of its body is 1.5 cm
○ Hosts: bean, pea, mung beans, kidney bean, leguminous crop, rice, millet and more
○ Distribution: Korea, Japan, Taiwan and more

late-instar bean bug nymph

The body length of bean bug adult is 1.5 cm. Its waist is thin and the third leg is longer. There are serrated prickles around the legs. The adult is 14~17 mm and its width is 2.5~3 mm. It is bigger than the average. A male bean bug has a black line on its head and chest and has a clear yellow discontinuity pattern. However, a female bean bug has light yellow line. The nymph's shape and behavior are similar to an ant.

early-instar bean bug nymph

Bean bugs did not cause serious damages. However, it appears everywhere after the number of predators of bean bug decreased due to the chemical pesticide. It appears 2~3 times a year and stays over the coldest season as an adult on the weed which is around covering or left covering. It gives damage to the crop in spring. The 1st generation of bean bug adult appears from late June to late July and the 2nd generation of the adult appears from early August to the middle of September.

The adults and larvae suck leguminous plant's juice. Therefore, a bean pod falls down or it becomes abnormal. Beans inside of pod stop growing and it turns into white or its surface becomes wrinkle. Moreover, it damages the leguminous plants like pea, millit, and rice. Not only it attacks the crop's seed but also the fruit.

There are several eco-friendly ways to control bean bugs; pheromone trap, light trap, predators of bean bug, natural pesticide. If you see the below picture, you can see the light traps in the farm.