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Insecticide resistance in Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) is a major constraint on the global production of cruciferous crops. For effective management of insecticide resistance, it is necessary to develop a molecular detection tool for predicting insecticide resistance levels based on the mutation frequency of target sites. In this study, a susceptible strain (SHggt) of P. xylostella was subjected to chlorantraniliprole and tetraniliprole selection under laboratory conditions to obtain the CHLSel and TETSel strains, respectively, to determine their resistance development, cross-resistance and mutation frequencies of the P. xylostella ryanodine receptor (Px RyR). In addition, the tetraniliprole resistance and the mutation frequencies of the Px RyR from 7 field populations were evaluated. Continuous selection over 30 generations resulted in resistance ratios (RRs) of 7,073.2-fold and 6,971.0-fold for the CHLSel and TETSel strains, respectively, and thousandfold increases in cross-resistance to unexposed diamides, e.g. cyantraniliprole and flubendiamide, were observed. For the field populations, three out of seven populations have developed more than thousandfold resistance to tetraniliprole. Among the three investigated target site mutations in Px RyR, only I4790K was detected in both laboratory-selected strains. However, 2 mutations, I4790K and G4946E, were detected in field populations. A positive correlation between RRs and K allele frequencies was observed in the laboratory-selected/relaxed strains and field populations of P. xylostella. These results suggest a possible link between the development of anthranilic diamide resistance and the frequency of the Px RyR I4790K mutation, which can be used to develop effective strategies for diamide resistance management in P. xylostella. [ABSTRACT FROM AUTHOR]

Laser devices produced via solution‐processed perovskite quantum dots (QDs) offer broad spectral tunability as well as ease of fabrication. Utilizing quasi‐bound states in the continuum (quasi‐BIC) modes, solution‐processed QD laser devices have been demonstrated with a nanostructure coated in a thin‐film gain media configuration. However, light leakage through thin‐film guiding from the cavity side edges becomes more pronounced when shrinking the cavity size, posing challenges for the miniaturization of quasi‐BIC‐based lasers. Here, the fabrication of well‐defined patterns of QDs via a solution process allows them to take advantage of the pattern edges to reduce losses through the cavity edges. A single‐mode BIC laser is reported by using CsPbBr3 QDs with a narrow linewidth of ≈0.1 nm. Importantly, a miniaturized quasi‐BIC laser is realized with a device size as small as 10 × 10 µm2, making it the smallest among existing solution‐processed BIC lasers. This work provides a strategy for developing ultra‐compact BIC lasers via solution‐processed gain media. [ABSTRACT FROM AUTHOR]

The recent development of perovskite-based lasers showcased the outstanding optical properties of the material such as high absorption coefficient and high quantum yield. The lasers were demonstrated in the form of nanowires and nanoplates, which are difficult to be integrated on a chip in the form of high-density arrays due to the difficulties in positioning them on the chip. The solution to this problem should be to use the well-known lithography process in the fabrication process of the lasers. In this work, we demonstrate several perovskite-based plasmonic lasers that were fabricated by using the lithographic in-mold patterning method that relies on the electron beam lithography process. The lasers utilized CsPbBr3 perovskite nanocrystals as the gain material and plasmonic distributed Bragg reflector grating structure as the optical feedback provider to achieve a low lasing threshold of 42.5 μJ/cm2 with a linewidth of 0.6 nm (FWHM) at room temperature. The use of the lithographic process in the fabrication of the lasers makes it possible to fabricate and integrate them on a chip in a relatively high-density manner, so that they can be used extensively in quantum optics and on-chip integrated photonics applications. [ABSTRACT FROM AUTHOR]

Extensive studies on lead halide perovskites have shown that these materials are excellent candidates as gain mediums. Recently, many efforts have been made to incorporate perovskite lasers in integrated optical circuits. Possible solutions would be to utilize standard lithography with an etching/lift-off process or a direct laser etching technique. However, due to the fragile nature of the lead halide perovskites which gives rise to significant material deterioration during the lithography and etching processes, realizing a small-size, low-roughness, and single-mode laser remains a challenge. Here, a lithographic in-mold patterning method realized by nanocrystal concentration control and a multi-step filling-drying process is proposed to demonstrate CsPbBr 3 nanocrystals distributed-Bragg-reflector (DBR) waveguide lasers. This method realizes the patterning of the CsPbBr 3 nanocrystal laser cavity and DBR grating without lift-off and etching processes, and the smallest fabricated structures are obtained in a few hundred nanometers. The single-mode lasing is demonstrated at room temperature with a threshold of 23.5 μJ cm -2 . The smallest full width at half maximum FWHM of the laser output is 0.4 nm. Due to the fabrication process and the DBR laser geometry, the lasers can be fabricated in a compact array, which is important for incorporating perovskite-based lasers in complex optoelectronic circuits.