Abstract: In 2022，a trial was conducted in Wulong Village，Xipu Town，Dongshan County，Fujian Province，China，to control the Lymantria xylina larvae using single and combined applications of Beauveria bassiana and Metarhizium anisopliae powder cannons in the protective forests of Casuarina. The results indicated that during the 2～3 instar larval stage of L. xylina larvae，when 60 B. bassiana powder cannons were applied per hectare in the forest，the adjusted control efficacy reached over 78%. Similarly，when 30 M. anisopliae fungal powder cannons were applied per hectare，the adjusted control efficacy exceeded 80%. Furthermore，when 15 B. bassiana powder cannons and 15 M. anisopliae powder cannons were applied per hectare in combination，the adjusted control efficacy reached over 84%. These findings suggested that the application of B. bassiana and M. anisopliae powder cannons in forest environments for L. xylina larvae control holds promising prospects，and their combined use also demonstrates certain synergistic effects.