water pest, rice pest

흰등멸구 피해
흰등멸구 피해
Rice leafroller
lepidoptera pyralidae

О Scientific name: Cnaphalocrocis medinalis (Guenee)
О English name: Rice leafroller
О Size: the length of its adult's wings are around 18 mm 
О Host: rice, barley, wheat
О Distribution: Korea, Japan, China, Taiwan, India, Australia, New Guinea, the Southeast Asia and more. 
 
흰등멸구 피해
흰등멸구 피해
The length of wings is around 18 mm. Rice leaf roller's head is white yellow and its body is brown yellow. The color of front wings are yellow and its front hem is covered with something like brown scales powder. There is brown fur on the middle of front hem. The edge of the front wings is dark brown. 
 
흰등멸구 피해
흰등멸구 피해
According to the recent research, the rice leaf roller came to Korea from abroad. The number of occurrence and damage are different every year. It is not sure whether the insect stays over the coldest season or not. It is considered to appear the second to the third generation in a year.  The adult insect stays while putting its belly edge high between rice leaves or weed in the daytime and it spawns or mates after sunset. Moreover, it is phototaxis. Its egg is flat and oval. The rice leaf roller spawns 1 ~ 2 eggs on the rice leaf. The scattering period is 5~7 days, the period of the larva is around 20 days and the period of its pupa is 8~15 days. The lifespan of moth is 9~20 days.
 
흰등멸구 피해
흰등멸구 피해
Its larva is green yellow and when it grows up it turns to red slowly. Generally, rice leaf roller damages the crop after it rolls rice leaf vertically one by one and it files several parts.  However, sometimes it files 2~3 leaves together and damages it.  The damaged leaf is left with only its epidermis and the insect moves to another leaf if the damaged leaf withered. You will be unable to see green rice in the rice paddy and rice's ear and grain filling become abnormal if the damage by rice leaf roller is the worst. Rice leaf roller is similar to Cnaphalocrocis exigua but it does not cover the rolled leaf up and down and its larva tends to fall down quickly if you touch it. 
 
흰등멸구 피해
흰등멸구 피해


Translated by Sunyoung Cho

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