This study aims to develop eco-friendly botanical pesticides. Dried fruits of star anise ( Illicium verum Hook.f. (Austrobaileyales: Schisandraceae)) were extracted with methyl alcohol (MA), ethyl acetate (EA), and petroleum ether (PE) at 25°C. The constituents were determined by gas chromatography-mass spectrometry, and the repellency and contact toxicity of the extracts against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) adults were tested. Forty-four compounds, whose concentrations were more than 0.2%, were separated and identified from the MA, EA, and PE extracts. The extraction yields of trans-anethole, the most abundant biologically active compound in I. verum , were 9.7%, 7.5%, and 10.1% in the MA, EA, and PE extracts, respectively. Repellency increased with increasing extract dose. The average repellency rate of the extracts against S. zeamais adults peaked at 125.79 µg/cm 2 72 hr after treatment. The percentage repellency of the EA extract reached 76.9%, making it a class IV repellent. Contact toxicity assays showed average mortalities of 85.4% (MA), 94.5% (EA), and 91.1% (PE). The EA extract had the lowest median lethal dose, at 21.2 µg/cm 2 72 hr after treatment. The results suggest that I. verum fruit extracts and trans-anethole can potentially be developed as a grain protectant to control stored-product insect pests. Other active constituents in the EA extract merit further research.

Entomopathogenic fungi and predatory mites can independently contribute to suppressing the two-spotted spider mite, Tetranychus urticae Koch. It is important to assess the risk of possible fungal infections in predators when a combination of them are being considered as a tandem control strategy for suppressing T. urticae. The first part of this study tested 12 Beauveria bassiana isolates for virulence in T. urticae. Strains SCWJ-2, SDDZ-9, LNSZ-26, GZGY-1-3 and WLMQ-32 were found to be the most potent, causing 37.6-49.5% adult corrected mortality at a concentration of 1 × 10 m/L conidia 4 days post-treatment. The second part evaluated the pathogenicity of these five strains in five species of predatory phytoseiid mites. The bioassay results indicated that all adult predatory mite mortalities ranged from 7.5 to 9.1% 4 days post-treatment. No viable fungal hyphae were found on predator cadavers. Observations with scanning electron microscopy revealed that conidia were attached to the cuticle of predatory mites within 2-12 h after spraying with strain LNSZ-26, and had germinated within 24-36 h. After 48 h, conidia had gradually been shed from the mites, after none of the conidia had penetrated the cuticular surfaces. In contrast, the germinated conidia successfully penetrated the cuticle of T. urticae, and within 60 h the fungus colonized the mite's body. Our study demonstrated that although several B. bassiana strains displayed a high virulence in T. urticae there was no evident pathogenicity to phytoseiid mites. These findings support the potential use of entomopathogenic fungus in combination with predatory mites in T. urticae control programs.

The brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a destructive invasive pest and has become one of the most economically-important rice pests in China. Effective control measures are desperately needed. Entomopathogenic fungi, such as Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae) and B. brongniartii (Saccardo), have shown great potential for the management of some sucking pest species. In this study, to explore alternative strategies for sustainable control of the sucking pest population, nine isolates of Beauveria from different pests were bioassayed under the concentrated standard spray of 1000 conidia/mm 2 in laboratory. The cumulative mortalities of adults ranged from 17.2 to 79.1% 10 days after inoculation. The virulence among all tested isolates exhibited significant differences (at p = 0.05). The highest virulent isolate was Bb09, which killed 79.1% of the treated insects and had a median lethal time of 5.5 days. Its median lethal concentration values were estimated as 134 conidia/mm 2 on day 10. The chitinase activities of nine isolates were also assayed. The results showed that the chitinase activity (18.7 U/mg) of isolate Bbr09 was the highest among all tested isolates. The biological characteristics of these strains, including growth rate, sporulation, and germination rate, were further investigated. The results showed that strain Bbr09 exhibited the best biological characteristics with relatively higher hyphal growth rate, the highest spore production, and the fastest spore germination. The isolate of Bbr09 had strong pathogenicity and exhibited great potential for sustainable control of N . lugens .

Dielectric properties of materials influence the interaction of electromagnetic fields with and are therefore important in designing effective dielectric heating processes. We investigated the dielectric properties (DPs) of pecan kernels between 10 and 3000 MHz using a Novocontrol broadband dielectric spectrometer in a temperature range of 5–65 °C and a moisture content range of 10–30% wet basis (wb) at three salt levels. The dielectric constant (ε′) and loss factor (ε″) of the pecan kernels decreased significantly with increasing frequency in the radio frequency (RF) band, but gradually in the measured microwave (MW) band. The moisture content and temperature increase greatly contributed to the increase in the ε′ and ε″ of samples, and ε″ increased sharply with increasing salt strength. Quadratic polynomial models were established to simulate DPs as functions of temperature and moisture content at four frequencies (27, 40, 915, and 2450 MHz), with R2 > 0.94. The average penetration depth of pecan kernels in the RF band was greater than that in the MW band (238.17 ± 21.78 cm vs. 15.23 ± 7.36 cm; p < 0.01). Based on the measured DP data, the simulated and experimental temperature-time histories of pecan kernels at five moisture contents were compared within the 5 min RF heating period.

The fresh Chinese hickory nuts (Carya cathayensis sarg.) were exposed to airborne ultrasound‐assisted convective drying and microwave‐assisted convective drying, as well as their combination. We investigated the effect of different drying schemes on process kinetics and quality characteristics. The global model of drying kinetics based on coupled ordinary differential equations was used to describe the moisture and material temperature profiles during drying. Application of ultrasound and microwave in convective drying reduced drying time in the range of 14.0–56.6%, but the maximum savings was found for simultaneous exposure of convection, ultrasound, and microwave with the range of 73.6–84.2%. The globally mathematical model was successfully used to simulate the real drying kinetics processes. The quality properties about the content of heat‐sensitive bioactive substances such as phenolic, flavonoid, proanthocyanidin, individual phenolic compounds, as well as antioxidant capacity in convective drying assisted with microwave (100 W) and ultrasound (200 W; CU2M1) are found to be significantly higher than the other groups. The results allow stating ultrasound increase drying efficiency, as expected by reducing the drying time there is less damage to the product. Practical Application In this work, we designed an experimental scale hybrid dryer that equipped with hot‐air convective drying, ultrasound generator and microwave drying system to dehydrate Chinese hickory nut and the effect of different drying schemes on the drying kinetics and product characteristics were investigated. This is an innovative technology of microwave and ultrasound hybrid drying to produce dried hickory products. Application of ultrasound and microwave in convective drying reduced drying time in the range of 14–56.6%, but the shortest drying time was observed for simultaneous action of convection, ultrasound, and microwave. The results of qualitative analysis showed a product improvement due to ultrasound as compared to convective drying and microwave‐convective drying.