Fall Armyworms on March Across Africa

 

A species of armyworm has spread to over 20 African countries and threatens Africa's main food crop -- maize¹.

The warning comes from the United States Agency for International Development, or USAID.

Joseph Huesing works as an advisor² to USAID. He suspects the fall armyworms were transported to Africa from the American state of Florida or islands in the Caribbean.

Huesing says the insects are attacking maize crops -- also known as corn -- in African countries south of the Sahara desert.

"From Nigeria and Ghana, all the way to South Africa to Ethiopia,” he told VOA. “The most recent one is South Sudan, which reported fall armyworm infestation³ toward the end of June.”

Huesing thinks fall armyworms are a big threat to African agriculture. When they invade a maize field, he said, the insects can eat 30 percent or more of the crop. They also eat other crops.

A Challenge to Control

The fall armyworms got their name from fall, or autumn -- the time of year when they do the most damage in the northern United States. The first published report describing their presence in Africa appeared in early 2016. It suggested the insects had already been there for a year.

For several reasons, the fall armyworms may pose more problems for farmers than the African armyworm, which is native to Africa.

Fall armyworms can reproduce continuously under warm, moist conditions, says Yene Belayneh of USAID. He noted⁴ that they can feed off of more than 80 species in 27 plant families.

As adults, fall armyworms can fly up to 100 kilometers a day if pushed by winds. Some armyworms have found a ride on modern aircraft.

For this reason, Belayneh said, communication is especially important. “If there is an outbreak, for example in Ethiopia, alerting Sudan or Eritrea would be a wise thing,” he said.

In fact, the insects are in Ethiopia. The country's Plant Protection Directorate reported that as of July 10, fall armyworms have infested⁵ more than 440,000 hectares of crops. It said that about 305,000 hectares had been protected.

Harder to detect

But chemical treatments may be less effective with the new invaders⁶ than with the African armyworms. The fall armyworm enters “the plant and feeds from inside," says Belayneh. This makes the insect harder to recognize and harder to kill.

The species is defenseless in cold weather, but freezing conditions are rare in much of Africa.

Regina Eddy⁷ heads USAID's armyworm response team. She says her team’s goal is to provide training and technical choices. She identified Brazil as a model for fighting armyworms. A recent USAID report noted that Brazil spends an estimated $600 million each year to control the insects.

One control measure experts are taking is to more carefully inspect food arriving at African airports. The fall armyworms may have arrived on the continent through a food shipment from overseas.

The fall armyworm is not causing a crisis yet. But Belayneh told VOA no one is taking the situation lightly.

I’m Mario Ritter.

Words in This Story

species – n. a group of similar, animals, insects or plants

infestation – n. the act of spreading on or over (something) in a troublesome way

pose – v. to create; to ask

moist – adj. moderately wet

response – n. an act of answering or reacting to something

1 maize   

n.玉米

参考例句：

• There's a field planted with maize behind the house.房子后面有一块玉米地。
• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。

2 advisor   

n.顾问，指导老师，劝告者

参考例句：

• They employed me as an advisor.他们聘请我当顾问。
• The professor is engaged as a technical advisor.这位教授被聘请为技术顾问。

3 infestation   

n.侵扰，蔓延

参考例句：

• The premises were treated for cockroach infestation.因蟑螂成灾，这些房屋集中进行了灭蟑活动。
• Parts of California are suffering from an infestation of oriental fruit flies.加利福尼亚的部分地区正遭受东方果蝇的大肆侵袭。

4 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

5 infested   

adj.为患的，大批滋生的（常与with搭配）v.害虫、野兽大批出没于( infest的过去式和过去分词 )；遍布于

参考例句：

• The kitchen was infested with ants. 厨房里到处是蚂蚁。
• The apartments were infested with rats and roaches. 公寓里面到处都是老鼠和蟑螂。

6 invaders   

入侵者，侵略者，侵入物( invader的名词复数 )

参考例句：

• They prepared to repel the invaders. 他们准备赶走侵略军。
• The family has traced its ancestry to the Norman invaders. 这个家族将自己的世系追溯到诺曼征服者。

7 eddy   

n.漩涡，涡流

参考例句：

• The motor car disappeared in eddy of dust.汽车在一片扬尘的涡流中不见了。
• In Taylor's picture,the eddy is the basic element of turbulence.在泰勒的描述里，旋涡是湍流的基本要素。