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The fungus, Esteya vermicola has been proposed as biocontrol agent against pine wilting disease caused by Bursaphelenchus xylophilus. In this study, we reported the effects of temperature and different additives on the viability and biocontrol efficacy of E. vermicola formulated by alginate-clay. The viability of the E. vermicola formulation was determined for six consecutive months at temperature ranged from -70 to 25 °C. The fresh conidia without any treatment were used as control. Under the optimal storage conditions with E. vermicola alginate-clay formulation, the results suggested that E. vermicola alginate-clay formulation with a long shelf life could be a non-vacuum-packed formulation that contains 2 % sodium alginate and 5 % clay at 4 °C. Three conidial formulations prepared with additives of 15 % glycerol, 0.5 % yeast extract and 0.5 % herbal extraction, respectively significantly improved the shelf life. In addition, these tested formulations retained the same biocontrol efficacy as the fresh conidial against pinewood nematode. This study provided a tractable and low-cost method to preserve the shelf life of E. vermicola.

Esteya vermicola, an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against pinewood nematodes. In order to improve the growth rate, sporulation and proportion of lunate conidia, the optimization of pH value for E. vermicola was tested. The diameter and dry mass of E. vermicola in PDA medium were increased greatly at pH 5 after 15 days, while the diameter and dry mass of E. vermicola were inhibited at pH 9 and 10. The sporulation of E. vermicola in PDA or PDB medium was highest at pH 6, 2.0 × 10 7 and 1.4 × 10 7 CFU/ml, respectively. The proportion of lunate conidia in PDA medium was highest at pH 4, while the proportion of lunate conidia in PDB medium was highest at pH 7.