微菌核是许多植物病原真菌产生的越冬结构,目前还没有关于白僵菌微菌核的报道。用含不同氮源的介质培养出了2株白僵菌菌株，RSB和SZ21的微菌核。在液体培养条件下，2株菌株不仅能产生典型的芽孢和菌丝，还能产生微菌核。在以玉米粉（RSB和SZ21菌株分别为6.5×10² 和6.3×10² mL^-1）为氮源的介质中产生的微菌核浓度高于以大豆粉(RSB和SZ21菌株分别为2.5×10² 和2.2×10² mL^-1)为氮源的介质。菌株SZ21产生的芽孢浓度（在以大豆粉和玉米粉为氮源的介质中，分别为17.9×10⁵和7.4×10⁵ L^-1）高于RSB菌株的芽孢浓度（在以大豆粉和玉米粉为氮源的介质中，分别为14.8×10⁵和6.2×105 L^-1）。含有硅藻土的微菌核制剂能在真空干燥（<5%湿度）后存活下来，并且对于活力没有显著影响。干燥后的微菌核颗粒在水洋菜培养基上复水和培养后，能够萌发菌丝和产生高浓度的分生孢子。将微菌核颗粒预混到土壤中能引起西花蓟马Frankliniella occidentalis (Pergande)土栖阶段的高死亡率。这是首次报道白僵菌的微菌核的培养，并为用虫生真菌防治土栖昆虫提供了一个新的方法。  

  

Microsclerotia (MS), overwintering structures produced by many plant pathogenic fungi, have not been described for Beauveria bassiana.Two strains of B.bassiana, RSB and SZ21, formed MS in shake flask cultures using media with different nitrogen sources.Both strains produced MS in addition to typical blastospores and mycelia.Strain SZ21 (17.9×10⁵ and 7.4×10⁵ L^-1 in media with soybean powder and corn flour, respectively) produced higher concentrations of MS than strain RSB (14.8×10⁵ and 6.2×10⁵ L^-1 in media with soybean powder and corn flour, respectively) of B.bassiana. Microsclerotial preparations of B.bassiana containing diatomaceous earth survived vacuumdrying (to <5 % moisture) with no significant loss in viability.Rehydration and incubation of vacuum-dried MS granules on water agar plates resulted in hyphal germination and sporogenic germination to produce high concentrations of conidia.Bioassays using soil-incorporated, vacuum-dried MS preparations resulted in significant infection and mortality in soil-dwelling stages of the western flower thrip, Frankliniella occidentalis (Pergande).This is the first report of the production of sclerotial bodies by B.bassiana and provides a novel approach for the control of soil-dwelling insects with this entomopathogenic fungus.