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Summary

This presentation discusses the challenges and insights from bioassay experiments aimed at controlling pests like the fall armyworm (FAW) and red palm weevil (RPW) in the Philippines. Key points include the development of a new artificial diet for FAW larvae, testing biopesticides, and refining control methods using neonate larvae. The results show promising potential for biopesticides like Magic Grow and Magic Kill. Additionally, the team is exploring genetic variation in pests and refining biopesticide delivery methods for targeted control, especially with RPW using trunk injections and acoustic technology for pest detection.

Takeaways

• 😀 The Philippines has been dealing with the fall armyworm (Spodoptera frugiperda) since 2016, and it has spread across the entire country, posing significant agricultural challenges.
• 😀 The Department of Agriculture, alongside other agencies like the Department of Science and Technology, is engaged in research and development to control the fall armyworm.
• 😀 A major challenge in conducting bioassays was developing an effective artificial diet for the fall armyworm. Previous diets like Cero and Niin did not work, leading to the creation of a new diet, PCRU.
• 😀 The successful PCRU diet demonstrated significantly lower mortality and higher egg mass production compared to the previously tested diets.
• 😀 The bioassay process involved using neonate larvae for testing, ensuring the insects were healthy before exposure to treatments, which were essential for reliable results.
• 😀 A critical factor in the bioassay process was developing an efficient oviposition chamber for the fall armyworm, which helped ensure a reliable egg production and successful test results.
• 😀 Bioassay experiments were conducted using various biopesticides, such as Bacillus thuringiensis (Magic Grow, Magic Kill), and the efficacy was compared to a positive control (Prebaton).
• 😀 The bioassay showed that Bacillus formulations (Magic Grow and Magic Kill) had higher mortality rates compared to the synthetic pesticide, indicating their potential as alternatives for controlling fall armyworm.
• 😀 The bioassay results revealed that larval mortality increased with higher concentrations of the tested biopesticides, though further verification is needed to confirm their effectiveness in the field.
• 😀 The research will continue, focusing on exploring the toxin composition of Bacillus species and optimizing biopesticide formulations for fall armyworm control.
• 😀 In addition to fall armyworm, the speaker discussed the red palm weevil as an emerging agricultural pest in the Philippines, with ongoing bioassay work to find effective biopesticides and control strategies for it.

Q & A

What is the significance of the fall armyworm issue in the Philippines?

The fall armyworm (Spodoptera frugiperda) has spread across the Philippines since 2016, impacting crops nationwide. It is a significant agricultural pest, and various management strategies are being explored, including research and development by the Department of Agriculture and the Department of Science and Technology.

What were the challenges faced in developing an artificial diet for the fall armyworm?

The main challenge was that the pre-existing artificial diets, like Cero and Niin, did not work for the fall armyworm in their experiments. The research team had to develop their own artificial diet, called PCRU, by combining elements from different diets, which proved effective for rearing the larvae.

What role does the artificial diet play in the bioassay of fall armyworms?

The artificial diet is crucial as it sustains the fall armyworm larvae through all six stages of development. A successful diet ensures that the bioassay can accurately test the efficacy of biopesticides and other treatments. The researchers also used food coloring to monitor the larvae's feeding behavior.

Why is the neonate larva stage important for fall armyworm bioassays?

The neonate (newly hatched) larva stage is critical for testing the efficacy of pesticides and biopesticides. At this stage, the larvae are more vulnerable and can give a clearer indication of the treatment's effectiveness. The researchers focused on this stage for consistent and reliable results.

What biopesticides were tested in the study, and what were the results?

The study tested several biopesticides, including formulations of Bacillus thuringiensis (such as Astron, Magic Kill, and Magic Grow). The results showed that both Magic Grow and Magic Kill had higher mortality rates in the larvae, suggesting their potential for controlling fall armyworm populations.

How did the researchers incorporate biopesticides into the artificial diet?

Initially, the researchers tested diet incorporation by mixing biopesticides into the artificial diet. However, this approach did not work as effectively as topical application. The team found that coating the surface of the diet with the biopesticide was more successful for controlling the fall armyworm larvae.

What role did environmental conditions and chamber setup play in the bioassay?

The researchers emphasized the importance of a well-designed and efficient rearing chamber for conducting the bioassay. The setup had to ensure that larvae could be properly housed, monitored, and harvested. Proper environmental conditions, including temperature and humidity, were also crucial for obtaining reliable results.

What were the next steps after the initial fall armyworm bioassay results?

The next steps involve continuing the experiments with biopesticides to further verify their effectiveness. The researchers plan to explore the toxin composition of Bacillus species like Bacillus subtilis and Bacillus amyloliquefaciens and expand their bioassay to assess the long-term effects of different biopesticides.

What is the status of the red palm weevil problem in the Philippines?

The red palm weevil is emerging as a major pest, particularly in coconut plantations in the Philippines. It poses a significant threat to the coconut industry, and researchers are exploring methods like trunk injection treatments and acoustic technology to detect and control the infestation.

How do genetic differences in red palm weevils affect bioassays and control methods?

The researchers noticed that there are genetic variations between the red palm weevil populations found in the mainland and islands of the Philippines. These differences could affect the effectiveness of biopesticides and control strategies, suggesting that bioassays should consider genetic diversity to identify the best control methods.