A team of experts from the Plant Protection and Research Institute is currently in the field assessing the extent of the invasion.

AN invasion by fall armyworm (FAW) into the country’s seven farming provinces could devastate an otherwise promising maize crop, more so as it emerged this week that there are no proper chemicals to control the pest.
With the country having been caught pants down, researchers are still busy trying to establish the extent of the damage.
The invasive voracious alien worm is native to tropical and sub-tropical regions of the Americas.
It might have found its way into the country through consignments of grain imports because Zimbabwe’s phytosanitary measures had been relaxed in order to expedite food relief efforts.
This followed the 2015/16 El Nino-induced drought, which forced the country to import the staple grain in order to avert starvation.
Most of the imports were from Zambia, with some coming from as far as South America.
Agriculture, Mechanisation and Irrigation Development Minister, Joseph Made, said the country is yet to assess the extent of the FAW infestation, which is most devastating under the prevailing weather conditions.
“For a proper assessment, let us wait for the team that is busy in the field assessing the extent of the damage,” Made said, while advising farmers to be on high alert.
A team of experts from the Plant Protection and Research Institute is currently in the field assessing the extent of the invasion.
While agronomists are scratching their heads over the bug’s origins, the deadly caterpillar is busy chewing away maize fields in the country’s seven maize-producing provinces at a time when available pest control chemicals are proving to be ineffective in destroying it.
The FAW larvae is conspicuous in colour, very active and voracious at feeding during an outbreak, but post outbreak, the larvae that survives, appear superficially to be a different species — especially to an untrained eye.
It is in this form that it is able to hide at the bases of grasses and survive between outbreaks.
Agronomists first thought it was the Chilo worm when it first started to destroy early planted maize crop in November last year.
But even after positively identifying it, the country is yet to find the correct chemicals, let alone import them at a time when Zimbabwe is unable to raise enough foreign currency to import raw materials to manufacture top dressing fertiliser critically needed to boost yields.
The available chemical — Carbaryl 85 Wettable Powder — has proved ineffective with some agronomists recommending plant- by-plant drenching, which does not guarantee success.
In Mexico, the birthplace of maize, farmers there battle the pest using synthetic insecticides.
Although the Financial Gazette could not readily establish the type of synthetic insecticides the Mexicans are using to control FAW, they may include chemicals such as DDT and Dursban.
DDT was once widely used in Zimbabwe to fight mainly the tsetse fly, but its use was banned many years ago.
Zimbabwe, which was devastated by an El-Nino-induced drought last year, was the second country in southern Africa to reports an outbreak of the worms with latest reports suggesting that some 2 000 hectares of maize fields have been chewed bare by the worm in Malawi.
In neighbouring Zambia, the military has been deployed to battle the scourge that has infested 124 000 hectares of maize fields, with reports from there indicating that some fields have been completely wiped out.
Zambia’s Vice President, Inonge Wina has said the pests were “posing a big threat to food security in the country. They have come with such a force of mass destruction that has to be faced head on. We need to put more effort into eradicating the worms.”
The FAW invasion comes amid efforts by Zimbabwe to control yet another version of the caterpillar called the African armyworm, which has become a common sighting during each of the country’s agricultural seasons.

Agriculture, Mechanisation and Irrigation Development Joseph Made

While the African armyworm is relatively easy to control because of its limited life cycles of about six, the FAW — which principally feeds on maize as well as cotton, soyabeans and vegetables — has 10 to 12 life cycles, giving Zimbabwean farmers sleepless nights as they scurry around to find the proper chemicals to destroy the pest.
Able to munch away a large field in a matter of days when mature, the FAW, scientifically known as Spodoptera frugiperda, is part of the order of moths and butterflies and is the larval life stage of a fall armyworm moth, according to web-based Wikipedia which further indicate that the pest can wreak havoc with crops if left to multiply.
Its name is derived from its feeding habits because they will eat everything in an area, and once the food supply is exhausted, the entire “army” marches to the next available food source.
The larvae are a dull yellow to gray with stripes running down the length of the body. The mature caterpillar is about 51 millimetres in length.
An infestation is hard to detect, the caterpillars migrate to new feeding areas in the cool of the night.
Zimbabwe Commercial Farmers Union president, Wonder Chabikwa, said the notorious pest was indeed proving very difficult to control.
“This is a new kind of pest for farmers. It is an unknown pest such that when the pest was first detected last year at the beginning of the farming season, trial and error methods were employed, but unfortunately the pest spread like wildfire to other provinces. The fall armyworm, unlike the usual armyworm that we are accustomed to, destroys the whole plant and has the potential to even destroy the cob.
Every maize growing province in the country has reported that the pest has affected their maize crops,” Chabikwa said, urging government to put the pest on the notifiable pest and diseases list considering that in 2015 the European and Mediterranean Plant Protection Organisation ranked the pest as an A1 quarantine pest.
A1 quarantine pests are those organisms that have been identified as posing the highest serious risk on other organisms.
Food and Agricultural Organisation sub-regional coordinator for southern Africa, Chimimba David Phiri said the fall armyworm could have devastating results on yields.
“Clearly, if not controlled, it can have devastating effects on production and food security.
But it appears that government has identified it quite early and all efforts are being made to control it before it becomes really very serious at country level.
Needless to say, government and communities need to continuously monitor the situation as the fall armyworm is very difficult to control,” Phiri said.
Phiri attributed the worm outbreaks to the frequent droughts over the years.
“The frequency of armyworm outbreaks in recent years is a result of extended drought conditions. Major outbreaks of armyworms are commonly preceded by extended droughts. The two previous dry seasons that Zimbabwe experienced with particularly severe drought effects of the El-Nino is very likely the reason we have for the current outbreak.
“It is unfortunately not possible to completely eradicate the armyworm. The population dynamics, onset and spread of armyworm outbreaks are strongly influenced by weather conditions; with frequent cycles of drought being the major driver of outbreaks.”
Government, through the Plant Protection and Research Institute, under the Ministry of Agriculture, Mechanisation and Irrigation Development is on high alert and has started training extension officers and farmers on effective ways of controlling the pest.
“The trick is early detection and early control before the crop reaches knee level because the pest has the potential to re-produce on the same maize field 10 times,” Plant Protection Institute chief entomologist, Godfrey Chikwenhere said.
Although the pest can be resistant to pesticides, farmers have been urged to use Carbaryl 85 Wettable Powder, but because the worm has about 10 to 12 life cycles and requires new techniques in the control and application of the pesticides, control in some areas has been ineffective.
Farmers have been urged to be diligent during scouting of their maize crops so that they do not miss the eggs that are usually found under the leaves.
Since the pest is alien to Zimbabwe, the Plant Protection and Research Institute is still conducting investigations on how the pest was introduced to Zimbabwe.
“We are still investigating its origins, but so far we discovered that the pest attacked Zambia’s wheat crop last year and we did not notice it. We will be holding a bi-lateral meeting with Zambia to discuss control of the pest and map the way forward,” Chikwenhere said.
As the season progresses, the pest is proving to be a menace as most farmers reported that the usual method of chemical application is proving to be ineffective.
“In addition to the re-infestation of the worms, if not properly controlled, the other effects include the development of resistance to the pesticides.
“Re-infestation poses high risk of the fall armyworm attacking the cobs and resulting in significant yield reduction. In the event of another dry spell during the season, there is a high possibility of another outbreak of the fall armyworm,” Phiri added.
The fact that the fall armyworm is a new pest to the region poses additional challenges as it will take more time before farmers and other stakeholders understand how to manage it.
Last year, the Southern African Development Community Regional Early Warning Bulletin for the 2016/17 rainfall season warned of pests and disease outbreaks because of the normal to above normal rainfall predicted.
“Farmers and supporting agencies should be prepared for incidences of pests and diseases for both crops and livestock. This is especially relevant in areas where specific pests/diseases tend to occur under conditions of high rainfall.
“In those areas where normal to above-normal rainfall is expected, and where high rainfall typically occurs, farmers and relevant institutions should intensify pest/disease monitoring and surveillance activities, as well as putting in place mechanisms to control potential outbreaks,” the report said.
The outbreak began in the Matabeleland North province before spreading into neighbouring areas and threatening the 2016/17 maize crop from whence the country’s food security hope lies after a devastating drought last year that saw the country harvesting 511 000 tonnes and leaving 4,1 million people in need of food aid.
In Brazil, the third largest maize producer in the world, the FAW is considered the most devastating pest causing damage estimated at more than US$400 million annually.
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