ADDING SEVERAL TYPES OF INSECT FLOUR TO INCREASE THE VIRULENCE OF METARHIZIUM ANISOPLIAE LOCAL ISOLATES AGAINST PESTS CYLAS FORMICARIUSNina Jeni Lapinangga, Jemrifs H. H. Sonbai and Jacqualine A. Bunga
The productivity of sweet potato in Timor Tengah Selatan (TTS) Regency is still far below the national productivity. The limiting factor is the attack of the pest Cylas formicarius both in planting and in storage. The aimed of this study was to examine the virulence of local isolates of Metarhizium anisopliae fungus cultured on growth media containing chitin. The study was conducted at the Plant Protection Laboratory from May-December 2021. The experiment was arranged using a Completely Randomized Design with five replications. The treatments were the type and concentration of chitin derived from three types of insects and arranged as follows: T0, control without chitin; T1, chitin from Gryllus assimilis 0.5%; T2, chitin from Gryllus assimilis 1%; T3, chitin from Locusta migratoria 0.5%; T4, chitin from Locusta migratoria 1%; T5, chitin from Oryctes rhinoceros 0.5%; and T6, chitin from Oryctes rhinoceros 1%. The results of this study showed that the addition of a chitin source to PDA growing media was able to increase conidia production, viability, and conidia virulence of M. anisopliae. Chitin also affects the virulence of M. anisopliae in C. formicarius which can increase the mortality percentage from 68% to 187%. Chitin in the form of flour derived from the insect O. rhinoceros with a concentration of 0.5% was an appropriate concentration to increase the viability and virulence of the M. anisopliae, besides that its protein content of 42.43% was high enough to support the production of quality entomopathogenic fungus.