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The National Crop Protection Center in the University of the Philippines Los Banos (NCPC-UPLB) in collaboration with Corteva Agriscience hosted a special seminar entitled “Fall Armyworm: Raising awareness on an invasive corn pest in Asia” last March 25, 2019 at the NCPC Auditorium, National Crop Protection Center Main Building, UPLB.

 Dr Gil L. Magsino, Director of NCPC and Mr Alfonso Antonio, representative of Corteva Agriscience, provided short messages to welcome the participants as well as to give the rationale of the activity. This was followed by the introductory lectures of two prominent scientists in UPLB- Scientist Mario V. Navasero and Dr Ireneo Lit – to give the audience the baseline information on the pest status of the armyworm group in the country. The highlight of the afternoon seminar was a lecture on the outbreak of fall armyworm in South Asia delivered in tandem by Drs Lakshmipathi Srigiriraju and Somsak Samanwong from Corteva Agriscience. Representatives from the academe, industry and government offices attended the said activity.

 

Armyworm in the Philippines

Sci. Navasero started his lecture with a review of the recent outbreak cases handled by the Plant Health and Quick Response Services in NCPC, to name: coconut leaf beetle in Quezon and Laguna, lophopid plant hopper in Compostella Valley, lanzones scale insect in Alaminos, Sta Cruz and San Pablo, cocolisap in Calabarzon, rice grain bug in M’lang and most importantly— 1) black armyworm in Calabarzon and Bataan; and 2) armyworm in Nueva Ecija, Pangasinan and Ilocos Sur. He also discussed the geographic range, biological attributes, natural enemies, alternate host plants of armyworm in relation to the development of a management plan for the two species of Spodoptera.

 On the other hand, Dr Lit presented an updated list of insect pests associated with field corn and reiterated that fall armyworm is not listed as a pest of corn in the last 100+ years in the Philippines. However, he mentioned the possible effects of climate change and global trade on the chances of biological invasions in our country- recommending more comprehensive field surveys of lepidopterans associated with corn, involvement of taxonomists in research as well as training of younger entomologists in insect taxonomy/parataxonomy and field entomology.

 

Fall armyworm in South Asia

According to Drs Srigiriraju and Samanwong, fall armyworm is a super pest because it spread across Africa in just 2 years. The pest affected 1.3 million hectares out of 9 million hectares of corn since the first report of infestation in Karnataka last June-July 2018. Fall armyworm was also reported to be present in Bangladesh, Nepal, Myanmar, Thailand and China. In Thailand, fall armyworm was able to spread out across the country within 4 months. In response to this, Thailand authorities monitored corn growing areas, set up a hotline number for fall armyworm monitoring and released an infographic brochure for the management of the pest. Corteva Agriscience, in collaboration with IRAC through CropLife Asia, conducted seminars on fall armyworm for the Thai authorities. This activity enhanced the capability of the concerned authorities to properly identify the pest and allowed to identify several regions with fall armyworm infestation.

 

What is fall armyworm and how do we manage it?

 The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) is one of the most devastating agricultural insect pests in the world. The destructive stage is the larva which is capable of defoliation that could lead to more than 70% yield reduction on corn. Two types or strains of fall armyworm are currently known: 1) maize strain- prefers maize, cotton, sorghum etc; 2) rice strain- prefers rice and pasture grasses such as Bermuda grass and Johnson grass. According to Drs Srigiriraju and Samanwong, the attributes of fall armyworm that make it a devastating pest are the following: highly polyphagous, with high reproductive rate, with strong migratory tendencies and with cryptic larval feeding behavior.

 Management of fall armyworm requires the following approaches: 1) preventative and avoidance, 2) monitor and scouting and 3) suppression and control. The first approach involves regulatory strategies and use of cultural methods; the second approach constitutes monitoring of fall armyworm adults with the use of pheromone traps and field scouting; and the third approach requires the use of various methods such as biological methods (natural enemies), genetic methods (corn hybrids, Bt corn) and chemical methods (seed treatments, baits, foliar insecticides).

 

What’s next for Philippines?

 Drs Srigiriraju and Samanwong urged the Philippines authorities to take actions now- to deploy the necessary monitoring and surveillance systems for the early detection of the pest in various corn growing regions in the country. As of the moment, fall armyworm is a threat to the corn industry in the Philippines, and its spread and infestation in other countries in South Asia should serve as a warning for everyone that this super pest knows no boundaries- and the Philippines might suffer the same fate as in the other countries in Asia if we do not act “swiftly” on this matter.