Fall Armyworm and its damage in Nepal

 Writer:Chitra Bdr Bohara

Address:Marin rural municipality 6,sindhuli

Study: +2(plant science)

Time to time Nepalese farmers is facing lots of problems and challenges in agriculture. Lack of modern machineries for farming, promising high yielding seeds and breeds, poor market facilities, crop pests and diseases are the regular problems which they are facing since 

long time ago. Adding to these, recently a new challenge, related to the pest has been introduced in Nepal and it is estimated that it will causes huge losses of agriculture produce in future.Now a days in our country,the main problems or challenge for crop production is "Fall armyworm(Spodoptera frugiperda)". 

Armyworm is a deadly pest which has a voracious appetite for maize and other crops and its impacts would be huge for the Nepalese farmers and economy. The climatic conditions in Nepal are suitable for the establishment and multiplication of Armyworm populations, which could potentially cause up to 100% crop losses in Maize if notmanagedproperly.The government should take quick initiatives against the menace of armyworm. The larva are becoming resistant to many chemical pesticides thus, the concerned authority should prepare IPM plans and programs and formulate at farmers level to combat invasion of Armyworm.So,we need proper management practice  to control armyworm.

Lifecycle:

 Like other lepidopteron pest, armyworm has also four stages (Eggs, Larva, Pupa and Adult) in its life-cycle which is completed in 28-48 days depending on weather conditions. Armyworm can produce 4-6 generations in tropical regions whereas only 2 generations in temperate regions.

Larva feeds in large numbers of leaves and stems of crop, including maize, rice, wheat, millate, sorghum, sugerbeet, sugarcane, tobacco etc.In addition apple, grape, orange, papaya, peach and a number of flower are sometimes injured by armyworm.

Management of armyworm:

Its rate of reproduce is very fast i.e population of group is very large so it can damage large area of crop in short period of time . Only one method of controlling is not sufficient so Integrated Pest Management (IPM) measures should be practiced. 

Physical/Mechanical Methods:

• Frequent observation and estimation of pest population and losses should be done in the 

maize field.

• Collection and killing of larva and moths should be done manually in the field.

• Light traps and pheromone traps should be used in the field for the monitoring and mass 

trapping of moths.

Cultural Methods:

• Planting of maize should be done in the pocket areas.

• Use of resistant varieties

• Mixed and intercropping with trap crops such as legumes will have less infestation 

compared to sole cropping of corn.

• Pull crop like Napier grass is panted in the border which attracts the pest thus, armyworm 

can killed by spraying insecticides in Napier grass only.

• Avoid excessive use of fertilizers.

• Proper ploughing of field before planting helps to expose the pupa of armyworm to the 

birds and predators.

Biological Methods:

• The predators such as earwigs, ladybird beetles, ground beetles, flower bugs, ants, birds 

and bats helps to control the pest so they must be attracted and preserved.

• Neem based bio-pesticides can also be used for the management of the armyworm.

Finally we can also be use chemical Methods but it is not a perfect methods for feuture:

• Insecticides like Spinetoram @1ml per 2 liters water, Spinosad @1ml per 3 liters water, 

Emamectin Benzoate @ 1gm per 2.5L water and Chlorantraniliprole @ 1ml per 2.5L 

water should be used for the management of the pest.

• Treatment of seeds with Imidacloprid (48% FS) @ 4ml per kg seeds before sowing also 

helps in the management of the pest.

"Due to the lack of knowledge many farmer use pesticides haphazardly in our environment so 

farmer needs basic training and needs to prepare effective guidelines for proper use of pesticides for increase long life span in the Earth."