<![CDATA[The rhinoceros beetle (Oryctes rhinoceros) is one of the main pests of oil palm plantations, causing significant yield losses, especially in young stands. This study aimed to determine the effect and optimal combination of Metarhizium anisopliae doses and empty fruit bunch (EFB) thicknesses in controlling Oryctes rhinoceros larvae. The research was conducted at PT Bumihutani Lestari (Eagle High Plantation Tbk), Katingan District, Central Kalimantan Province, from December 2025 to February 2026. A factorial Randomized Block Design (RBD) was used with four levels of M. anisopliae doses (P0: control, P1: 60 g, P2: 80 g, P3: 100 g) and three EFB thickness levels (K1: 1 layer/10 cm, K2: 2 layers/20 cm, K3: 3 layers/30 cm), replicated four times (720 larvae total). Larval mortality, lethal time 50 (LT50), and cost analysis were observed. Data were analyzed using two-way ANOVA at 5% significance level followed by Duncan's Multiple Range Test (DMRT). The results showed that Metarhizium anisopliae doses and EFB thickness significantly affected Oryctes rhinoceros larval mortality from week two onward. The P3 (100 g) treatment produced the highest cumulative mortality of 13.00 larvae (86.67%). The P3K3 interaction yielded the highest mortality rate of 13.50 larvae (90%). LT50 analysis indicated that the fastest mortality (2.8 weeks) was achieved at the P3K1 combination. Cost analysis revealed that the 100 g dose is the most efficient for large-scale application. Metarhizium anisopliae at 100 g dose combined with 3-layer EFB is recommended as an environmentally friendly biocontrol agent for Oryctes rhinoceros management in oil palm plantations.]]>
