Biocontrol Potential of Local Trichoderma virens (Ascomycota: Hypocreaceae) Against the Different Developmental Stages of Spodoptera litura (Lepidoptera: Noctuidae)
Rea Sebumpan1,2*, Prakaijan Nimkingrat3 and Nanette Hope Sumaya1,2
1Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, A. Bonifacio Ave., Tibanga, Iligan City 9200, Philippines
2FBL-Nematology Research Group, Premier Research Institute of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, A. Bonifacio Ave., Tibanga, Iligan City 9200, Philippines
3Department of Entomology and Plant Pathology, Faculty of Agriculture, Khon Kaen University, Mittraphap Rd., Nai-Muang, Muang District, Khon Kaen, 40002, Thailand
*Corresponding author: email@example.com
Researchers have extensively investigated the various applications of Trichoderma virens (Ascomycota: Hypocreaceae), including its antimicrobial, antifungal, and plant-growth-promoting properties. However, the biological control potential of this organism against agricultural pests has yet to be assessed. One notable pest in the Philippines is the Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), a common cutworm. The fungal isolate, T. virens PPVS3A.22, was first subjected to testing using the last instar larvae of the superworm Zophobas morio (Fabricius) (Coleoptera: Tenebrionidae). Subsequently, it was also tested against various developmental stages of S. litura. On the sixth day of the experiment, it was observed that all larvae in the first and second developmental stages experienced complete mortality. In the fourth and fifth developmental stages, a mortality rate of 63.1% was observed when exposed to a suspension containing 2.68× 10^7, 6 × 10^8 and 3 × 10^9 conidia/ml, respectively. In contrast, a decrease in pupal mortality was noted in 2-day-old pupae (11.25%) compared to 5-day-old pupae, which exhibited a pupal mortality rate of 59.4% on day 6 when exposed to a suspension containing 6 × 10^8 and 3 × 10^9 conidia/ml, respectively. The research provides empirical support for the potential use of T. virens as a viable biological control agent against the economically significant insect pest, S. litura.