The present research aims to explore the occurrence and diversity of entomopathogenic fungi (EPF) in cultivated and uncultivated lands from different provinces of China and to search for EPF against Phyllotreta striolata. In this study, first, the EPF biodiversity from the soil of four provinces (Hunan, Hubei, Henan and Hebei) was surveyed. There were 302 fungal isolates obtained from 226 soil samples collected from croplands (114), arbor (79), grasslands (97) and fallow land (12); 188 EPF isolates were identified as 11 genera. The data indicate that Hubei Province has the greatest EPF diversity, with a Shannon Evenness Index (SHEI) value of 0.88. Here, the grassland, arbor and cropland had an EPF diversity with SHEI values of 0.81, 0.86 and 0.76, respectively, while the fallow land had the highest SHEI value of 1.00, which suggests that cultivation by humans affected the count and richness of soil fungi: the less human activity, the more kinds of fungi found. Finally, the pathogenicity of 47 fungal strains against the adult P. striolata was determined. Isaria javanica (IsjaHN3002) had the highest mortality. In conclusion, this study reports the EPF distribution and biodiversity in the soil from four provinces in China, showing that the amount and type of fungi in the soil varied by region and vegetation and that soil was one of the resources for acquiring EPF. The potential of I. javanica as a biocontrol must be studied further.

Plutella xylostella (Linnaeus) is one of the notorious pests causing substantial loses to numerous cruciferous vegetables across many nations. The sterile insect technique (SIT) is a safe and effective pest control method, which does not pollute the environment and does not produce drug resistance. We used proteomics technology and bioinformatics analysis to investigate the molecular mechanisms responsible for the effects of different doses of radiation treatment on the reproductive ability of male P. xylostella. A total of 606 differentially expressed proteins (DEPs) were identified in the 200 Gy/CK group, 1843 DEPs were identified in the 400 Gy/CK group, and 2057 DEPs were identified in the 400 Gy/200 Gy group. The results showed that after 200 Gy irradiation, the testes resisted radiation damage by increasing energy supply, amino acid metabolism and transport, and protein synthesis, while transcription-related pathways were inhibited. After 400 Gy irradiation, the mitochondria and DNA in the testis tissue of P. xylostella were damaged, which caused cell autophagy and apoptosis, affected the normal life activities of sperm cells, and greatly weakened sperm motility and insemination ability. Meanwhile, Western blotting showed that irradiation affects tyrosine phosphorylation levels, which gradually decrease with increasing irradiation dose.

Plutella xylostella (Linnaeus) mainly damages cruciferous crops and causes huge economic losses. Presently, chemical pesticides dominate its control, but prolonged use has led to the development of high resistance. In contrast, the sterile insect technique provides a preventive and control method to avoid the development of resistance. We discovered two genes related to the reproduction of Plutella xylostella and investigated the efficacy of combining irradiation with RNA interference for pest management. The results demonstrate that after injecting PxAKT and PxCDK5, there was a significant decrease of 28.06% and 25.64% in egg production, and a decrease of 19.09% and 15.35% in the hatching rate compared to the control. The ratio of eupyrene sperm bundles to apyrene sperm bundles also decreased. PxAKT and PxCDK5 were identified as pivotal genes influencing male reproductive processes. We established a dose-response relationship for irradiation (0–200 Gy and 200–400 Gy) and derived the irradiation dose equivalent to RNA interference targeting PxAKT and PxCDK5. Combining RNA interference with low-dose irradiation achieved a sub-sterile effect on Plutella xylostella, surpassing either irradiation or RNA interference alone. This study enhances our understanding of the genes associated with the reproduction of Plutella xylostella and proposes a novel approach for pest management by combining irradiation and RNA interference.

Weeds pose a significant threat to agricultural productivity, emphasizing the urgent need for developing innovative biological herbicides. Soil is a rich reservoir of fungi with potential herbicidal properties. The Xinjiang region of China, characterized by unique biodiversity shaped by geographical and climatic factors, is likely to harbor distinctive fungal resources that remain understudied. This study investigated the herbicidal potential of soil fungi by collecting 123 soil samples from 33 diverse habitats in Xinjiang and isolating 114 fungal strains. Morphological characteristics and ITS sequence analysis identified these strains as 24 species belonging to 12 genera. Subsequently, 24 representative strains underwent phytotoxicity assays using detached weed leaves. Strain Tapu14C02 demonstrated significant herbicidal activity against 11 weeds, including Amaranthus retroflexus , Bidens pilosa , and Celosia argentea . Further identification confirmed the strain as Talaromyces purpureogenus . Pot experiments were conducted to evaluate the herbicidal potential of the strain. The spore suspension at a concentration of 1.0 × 10 ⁸ spores/mL inhibited barnyard grass ( Echinochloa crus-galli ) seedling root length by 93.07%. Among the crude extracts from the fermentation broth, the ethyl acetate fraction exhibited the strongest herbicidal activity, causing complete inhibition of root growth at concentrations of 1000 µg/mL and 500 µg/mL. This study provides novel insights into the herbicidal potential of soil fungi in the Xinjiang region of China. IMPORTANCE: Weeds pose significant challenges by causing agricultural losses and ecological harm. Over the past decades, many weed species have developed high resistance to chemical herbicides, underscoring the urgent need for new biological herbicide alternatives. In this study, we isolated and screened herbicidal fungi from soil samples in Xinjiang with unique conditions of extreme arid. Notably, we discovered the T. purpureogenus strain Tapu14C02, which shows promising potential as a myco-herbicide. Both its conidia and fermentation broth exhibit broad-spectrum effectiveness against weeds. This research highlights the potential of fungal resources for sustainable agriculture.

The striped flea beetle (SFB), Phyllotreta striolata, is a significant pest of cruciferous crops. Entomopathogenic fungi (EPF) hold great promise for the integrated pest management (IPM) of the SFB. However, the lack of understanding of the different interactions between the SFB and EPF restricts the development of mycoinsecticides. This study aims to elucidate the interaction performance of the SFB with three EPF—Beauveria bassiana BbPs01 (Bb), Metarhizium robertsii MrCb01 (Mr), and Cordyceps javanica IjH6102 (Cj). The bioassay results indicated that the virulences of EPF to the SFB adults were recorded as Bb > Mr > Cj. Then, the EPF with distinct infection pathways were observed, in which Bb penetrated the SFB cuticle via germ-tubes and appressoria, Mr typically invaded using appressoria, while Cj employed germ-tubes. Moreover, the SFB with different symptoms following infection by the EPF species were recorded. Bb primarily caused SFB adults to lose their appetite, become sluggish, and die rapidly. In contrast, SFB adults infected with Mr often experienced shivering, uncoordinated movement, and slower death. Cj-infected larvae frequently displayed dendrite-like melanization originating from the spiracles, while infected adults exhibited weak shivering and slow death, which seems similar to Mr. Our findings provide novel insights into the interactions between EPF and insects and offer valuable materials for enhancing the application of mycoinsecticides in the control of the SFB.

The striped flea beetle (SFB), Phyllotreta striolata, is a major pest of Brassicaceae crops, causing substantial yield losses worldwide. Effective biocontrol strategies, particularly the development of mycoinsecticides, require the identification of virulent entomopathogenic fungi (EPF) and the establishment of reliable bioassay systems. However, establishing reliable bioassay systems for SFB has been particularly challenging, especially for larval stages due to their recalcitrant rearing requirements. This study aimed to establish a standardized bioassay protocol to evaluate EPF efficacy against SFB. A specialized larval collection apparatus was developed, and the virulence of three EPF strains (Beauveria bassiana BbPs01, Metarhizium robertii MrCb01, and Cordyceps javanica IjH6102) was assessed against both adult and larval stages using a radish slice-based rearing system. Intriguingly, BbPs01 and MrCb01 exhibited significantly higher LT₅₀ values in larvae than in adults, contrary to the typical pattern of greater larval susceptibility observed in most insect systems. We hypothesized that isothiocyanate—specifically sulforaphane, a compound abundant in radish tissues—exerts fungistatic effects that impair fungal growth and virulence. Follow-up experiments confirmed that radish-derived sulforaphane inhibited fungal activity. Through alternative host plant screening, Chinese flowering cabbage (Brassica campestris L. ssp. chinensis var. utilis) was identified as an optimal larval diet that minimally interferes with EPF bioactivity, enabling reliable virulence assessments. This study presents critical methodological advancements for SFB biocontrol research, providing a robust framework for standardized larval bioassay and novel insights into plant secondary metabolite interactions with entomopathogens. The optimized system supports the development of targeted mycoinsecticides and contributes to a deeper understanding of tri-trophic interactions in crucifer pest management.