ISOLATION, IDENTIFY, GROWTH AND PATOGENITY OF THE FUNGUS FROM THE LARVAE DIAMONDBACK MOTH (PLUTELLA XYLOSTELLA L.; LEPIDOPTERA: YPONOMUETIDAE)

• Main Author: Komalaningsih, Sri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2243
• Institution: Institut Teknologi Bandung

A study on entomogenous fungus used as a biological control agent has been caried out in the laboratory/greenhouse of the Department of Biology and I.U.0-ITB, and LEHRI, from July 1989 to July 1990. The fungus was collected from the infected larvae of the diamondback moth (DMB, Plutella xylostella L.) which was obtained from Pangalengan, Lembang and Cisarua, District of Bandung. The objectives of this study were (1) to isolate and identify the fungus infected the DMB larvae of the three different locations; (2) to evaluate the growth ability of fungus on various media; and (3) to determine the optimal temperature and relatif humidity for the fungus infection on the larvae of P. xylostella. Identification was done by using light microscope and scanning electron microscope (SEM). The fungus was grown in four different kinds of media viz: Potato Dextrose Agar (FDA), Corn Meal Agar (CMA), Brain Heart Infusion (BHI) and Saburaud Dextrose Agar (SDA). The fungus collected from Pangalengan, Lembang and Cisarua were incubated at 19°C, 20°C, 21°C, 22°C and 23°C, with the relative humidity of 85%, 90% and 95%. Based on the morphological characteristics, it was concluded that the pathogenic fungus attacked P. xylostella larvae from the three locations was Entomophthora sphaerosperma (Fresenius) synonym Zoophthora radicans (Brefeld). This fungus grew well on all media and produced colonies of fungus with the following diameters: 2,65 mm in PDA, 1,60 mm in CMA, 2,45 mm BHI and 1,55 mm in SDA. Artificial infections of E. sphaerosperma on P. xylostella larvae at temperature of 21° and relative humidity of 95% caused the highest percentage of larvae mortality.