The potential of entomopathogenic fungus Aspergillus oryzae in controlling subterranean termites (Isoptera: Termitidae) in Tanzania

Abstract

Subterranean termites pose significant economic and food loss during production requiring intensive use of pesticides that affect crop quality and market hence necessitating effective and sustainable biocontrol strategies for management. This study evaluated the efficacy of the entomopathogenic fungus Aspergillus oryzae Isolate; VB – MG938648 in controlling subterranean termites on crops. A field trial was conducted from April to June 2024 in different zones of Tanzania. All treatments were applied once using a 20 L knapsack pump fitted with fan spray nozzle which is ideal narrow calibrated to distribute liquid in all parts including flat surface of plant and undersides of the leaf. Application of all treatments was done once a week from 1730 h m. The results showed significant termite mortality rate ranging from 71.2 % to 87.6 % across different treatments and locations. The efficacy of Aspergillus oryzae as a biopesticide against subterranean termites in cocoa, macadamia, and coffee trees was significant high compared to control. The mortality rate was dose dependent where the highest concentration achieved high mortality rate compared to low concentration and control. The study demonstrates the efficacy of Aspergillus oryzae in attracting beneficial insect especially pollinators including; Andrena vicina, Apis mellifera, cruciscispidia chandleri, Hypotrigona gribodoi, Osmia lignaria, Pseudapis usambarae suggesting its potential as a termite biocontrol and increase yield through pollination in coffee plantations, a crop with high economic value in Tanzania. This study suggests the application of biopesticide for control of subterranean termites to reduce crop loss and the impact of chemical pesticides on biodiversity.