Larvicide effects of Bacillus sp isolated from soil against fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

Prolonged use of pesticides was known to have a negative impact on the environment, health, and living organisms. Therefore alternative pest control techniques need to be developed continuously. One pest eradication techniques that is believed to be safe for the environment is biological control. This study intended to evaluate the toxicity properties of 7 different isolates suspension of Bacillus sp. isolated from soil in a botanical garden in West Lampung against Spodoptera frugiperda larvae. Morphological characterization of protein crystals which are toxic to insects contained in the suspension was carried out microscopically at a magnification of 1000x. Then, each isolate suspension was tested for its toxicity properties on the 3rd instar larvae of S. frugiverda. The protein crystal morphology of the Bacillus sp isolate coded TB7 was similar to that of L. sphaericus. While the other six isolates (TMA 26, TBA 4, TBA 7, TB 5, BP 14, and TSR 6) had morphological characteristics similar to that found in the B. thuringiensis. The results of larvicide test showed that Bacillus sp isolates coded TMA 26, TBA 7, BP 14 and TB 5 caused mortality on day 3. TBA 4 isolates killed larvae on day 4, while isolates coded TSR 6 and TB 7 killed larvae on day 5. In conclusion, Bacillus sp isolate isolated from soil has toxic properties to the larvae of S frugiperda. So it is suggested that the bacterial isolate Bacillus sp can be used as a biological control agent for insect pests.