By Sarah Hannan As the State Ministry of Development of Sugarcane, Maize, Cashew, Pepper, Cinnamon, Cloves, Betel Production, and Promotion of Allied Products and Export awaits the crops to be harvested at the end of the Maha season which is fast approaching in order to look at estimating the overall yield loss caused by the fall armyworm invasion. Farmers are grappling with uncertainty on whether they would be betrayed yet again without being compensated for the losses they incurred. The reporting and sightings of the destruction caused by this season's fall armyworm invasion seemed to be quite high, with the menace reaching eight provinces. However, the Ministry of Agriculture assures that the damage caused would be halved since steps are in place to minimise yield damage. [caption id="attachment_114202" align="alignleft" width="263"] Fall Armyworm caterpillar rared at HORDI for study purposes[/caption] Department of Agriculture Director General Dr. W.M.W. Weerakoon stated that in comparison to the first wave of infestations that occurred in 2018, this time around, they are positive that the extent of crop damage will be far less, with a projected yield loss amounting to 5%. According to Department of Agriculture 2019 statistics, in the first attacks of fall armyworms, which lasted from end-August 2018 through January 2019 during the Maha season, out of the estimated maize growing extent of 82,539 hectares, the fall armyworm had attacked 54,416 hectares. Yet, the yield loss was estimated to be between 15-20%. Given that this time there is a dedicated state ministry that is to attend to this matter, and with Minister of Agriculture Mahindananda Aluthgamage earlier this month stating that farmer compensations would be streamlined so that they would receive compensation within a month from filing damage claims, it looks as if it is off to a promising start. State Ministry of Development of Sugarcane, Maize, Cashew, Pepper, Cinnamon, Cloves, Betel Production, and Promotion of Allied Products and Export Director of Development Ransilu Watawala, when contacted by The Sunday Morning, revealed: “We are yet to estimate the yield loss for this season, as the harvesting is yet to take place. It is after we assess the yield losses that we would be able to come to a conclusion as to who would be eligible to claim compensation. We have scheduled a meeting with the officials to obtain a field report update on 20 January, and will take a call on finalising the compensation scheme for this season.”

Unfulfilled promises

According to All Island Farmers Federation (AIFF) National Organiser Namal Karunaratne, some farmers, especially in the Ampara and Monaragala Districts, are yet to be compensated for the crop damages caused by the fall armyworm invasion in 2018.  The Government has taken measures to insure six agro-crops, within which maize cultivation is also included. The farmer compensation under such a scheme was not dispersed. Under that insurance scheme, crops are said to be insured against natural disasters and mismanaged pest attacks at Rs. 40,000 per acre of damaged crop. Given the field reports and the accounts of the agrarian development officers, it was clear that cultivation had commenced in different weeks, as some of the cultivation areas had waited for fair weather to settle in before sowing seeds. Unfortunately, this delay had allowed the fall armyworm to rapidly spread across cultivations as each field was cycling through various crop weeks, providing ample nesting grounds for the pest’s eggs to incubate, gestate, and commence their gradual attack. According to Department of Agriculture crop forecast reports, the extent of maize grown during this season amounts to 19,066 hectares (47,665 acres), out of which the districts that cultivated the highest amount of maize is recorded from Ampara with 4,853 hectares (12,132.5 acres), Anuradhapura with 3,497 hectares (8,742.5 acres), and Monaragala with 2,672 hectares (6,680 acres). Last December, the State Ministry had received estimations of predicted yield losses from the Ampara District (30%), Anuradhapura District (10%), Uva Province (15%), and North Western Province (25%), while from the other areas, the yield loss was estimated to be insignificant.

Research continues

Although the Rwandan Defence Force, earlier this month, arrived for a two-day fact-finding visit on the growing fall armyworm invasion in the country, there has been no update or follow-up to that visit, or as to what recommendations they wanted to share with Sri Lanka to take control of the pests. Meanwhile, the Department of Agriculture appointed a separate research unit at the Horticultural Crop Research and Development Institute (HORDI) in Gannoruwa to closely study the fall armyworm and research the natural measures that could be taken to control the pest with the least amount of impact to biodiversity of the cultivation and its surrounding areas. According to HORDI Principal Scientist – Entomology Senani Weligamage, the unit has been conducting continuous research since 2018, where they have two of their own scientists and undergraduates from the university to closely study the fall armyworm’s lifecycle and the predators that feed on its larvae during its early stages of growth. [caption id="attachment_114203" align="alignleft" width="300"] A parasitoid wasp (Telenomus remus) attempts to lay eggs in fall armyworm eggs[/caption] “We have so far identified 55 such predatory species that prey on the fall armyworm. However, we also observed that these species only thrive in cultivations that employ organic cultivation practices,” Weligamage explained. With the knowledge the research unit has gathered over the two years, they have now recommended that the best method to control the spread of the pest is through biological pest management. In order to effectively deploy this method, the unit advises that the identified predatory species should be encouraged to settle around the crop cultivations that are vulnerable for fall armyworm infestations. According to Weligamage, these predatory species vary from birds, spiders, dragon flies, ants, parasitoids, and even pathogens that will only be present in areas that are rich in biodiversity. At present, the research unit is conducting a study on a parasitoid wasp that lays eggs in fall armyworm eggs, known as Telenomus remus, which tends to thrive on mimosa sleeping grass flower nectar (Mimosa pudica, Mimosa hispidula) and creeping tick trefoil flower nectar (Desmodium triflorum).

Pest management knowledge kit  

“We are also looking at putting together a pest management knowledge kit for the farmers, which we improved, taking into consideration our research findings. It is important that the pest management steps should actually be followed after the yield has been harvested and during the intermittent period where the lands are left until the next cultivation season commences,” Weligamage added. HORDI suggested that the following steps should be followed to further reduce the crop damage caused by the fall armyworm, which could take place once again from August this year:

• Manually removing weeds from the cultivation land, rather than spraying a herbicide that could destroy plants such as mimosa sleeping grass and creeping tick trefoil that create an environment for Telenomus remus to thrive
• At the time of sowing maize seeds, farmers could set up pheromone traps in their field (i.e. six pheromone traps per hectare)
• Using organic manure
• Following the recommended spacing to plant the maize seeds
• Using intercropping or mix-cropping techniques to create barriers between maize cultivations
• Reducing the amount of nitrogen fertiliser used for the crops
• Obtaining Telenomus remus (egg parasitoids) from the Agrarian Service Centre or HORDI and releasing them during the first week of cultivating maize
• Maintaining the biodiversity of the area by allowing recognised herbs to grow around the crop
• Conducting regular observations from the time the seeds produce shoots (after the first week) to identify whether the fall armyworms have started to settle in
• A sugar solution which has 10% sugar could also be scattered in intervals to attract ants, spiders, and other insects that would feed on fall armyworm eggs or larvae
• Applying the Sinaloa native isolate of multicapsid nuclear polyhedrosis virus (SfMNPV) in the mornings will be effective to eradicate larval instars I, II, and III of the fall armyworm or if the caterpillar is less than 1 cm in length. Farmers are advised to apply the virus only over the saplings that are under attack
• The fall armyworm caterpillars that find their way into the whorl and then to the stalk will not get affected by the pesticides that are applied. Therefore, they need to be mechanically removed.
  • One method is to drop some water to the top of the whorl and when the stalk fills with water, the caterpillar would resurface. It can then be removed and placed in a container filled with kerosene oil
  • If not, the farmer can also use one of five pesticides the Department of Agriculture has recommended. About 10 ml of pesticide should be applied on each of the maize plants that have been attacked, using a pipette that can reach in to the stalk

• Additionally, bird baths or bird stands can be set up in the field to attract predatory birds such as mynahs and yellow-billed babblers (demalichcha) to feed on the fall armyworm caterpillars that are out of the cobs