Integrating Native Entomopathogens Into Fall Armyworm ( <i>Spodoptera frugiperda</i> ) Management in Ghana

The sustainable management of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), with minimal environmental footprint has been a priority in sub‐Saharan Africa since the pest’s invasion. Biological control agents have been proposed as key components of an integrated management strategy. This study evaluated the field efficacy of two native entomopathogens— Beauveria bassiana (fungus) and Metarhabditis rainai (nematode)—against FAW in maize production. Field trials were conducted over two cropping seasons in two different ecological zones, assessing six treatments: B. bassiana , M. rainai , a combination of B. bassiana + M. rainai , Bacillus thuringiensis (Bt: Bypel), emamectin benzoate (Attack), and an untreated control. Parameters assessed included FAW larval mortality, reinfestation rates, maize leaf and cob damage, and yield performance. Results showed that larval mortality caused by B. bassiana and M. rainai was significantly higher ( p &lt; 0.05) than in the control and comparable ( p &gt; 0.05) to Bt. and emamectin benzoate treatments. FAW reinfestation, leaf damage, cob damage, and yield losses were significantly lower ( p &lt; 0.05) in entomopathogen and insecticide treatments compared to the control. While Bt. was superior in reducing cob damage and improving yield, other parameters were similar among the entomopathogen and insecticide treatments. Treatment efficacy on larval mortality, reinfestation, and yield varied by location, whereas seasonality influenced leaf damage and yield. B. bassiana and M. rainai thus proved as effective as Bt and emamectin benzoate in FAW management, though their combination did not exhibit a synergistic effect. These two native entomopathogens can be incorporated into the FAW integrated management system in Ghana.