Oryctes rhinoceros, also known as Asian coconut beetle, is an important pest in this part of the world. Despite the name, this insect causes damages in other important economic plants such as cassava, sugarcane, oil palm, and other palm species. This insect goes through a complete metamorphosis, which involves stages of eggs, larvae, pupae, and adults. At larval stage, this insect consumes dead wood materials. Plant damage is caused by adult insects that consume the growing parts. These damages lead to reduced production and even death of the plants.
Such beetle infestation has been controlled by cultivation methods, chemicals, as well as biological agents. However, these treatments have not shown significant impacts in controlling Oryctes rhinoceros damages in the fields. Recent findings show that Metarhizium anisopliae application can effectively fill the role of curbing coconut beetle infestation.
Found in the soil, Metarhizium anisopliae causes diseases in insects by acting as a parasite. To utilize this fungus, we must first be able to produce a large amount of pure isolates. This can be achieved by initially growing Metarhizium anisopliae on a potato dextrose agar (PDA) then increasing the production in the potato dextrose extract solution. Metarhizium anisopliae can then be purified and applied to crops to prevent and/or eradicate Oryctes rhinoceros.
Indmira R&D division has carried studies on the effect of Metarhizium anisopleae as a biological pesticide in controlling the populations of important insect pests, such as scale insects (Phenacoccus manihoti), army worms (Spodoptera spp.), rice ear bug (Leptocorisa oratoria), and grasshoppers (Caelifera). Our findings show very promising results. On scale insects, application of Metarhizium anisopleae fungus at 1,5% is almost 100% effective. The highest success rate against the army worms is at 66,7% at the concentration of 2% Metarhizium anisopleae fungus. This treatment is least effective on grasshoppers with a result of 12% insect mortality rate.
These promising results show that Metarhizium anisopleae can be used to control other insect pests. Our R&D team will continue to research on this fungus as a biological pesticide on other destructive insects and other crops.