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Organosilicone adjuvants are widely used to increase insecticide application on targeted surfaces. In this work, our aim was to investigate side effects of imidacloprid treatment, either applied alone or in combination with organosilicone compounds, against Chrysoperla nipponensis, an important predator of aphids. Four types of organosilicones were mixed with imidacloprid at different concentrations. The toxicity of the mixture to C. nipponensis was measured under laboratory conditions. The LC50 and LC30 of imidacloprid applied alone and in combination with 0.05% organosilicone were determined. Imidacloprid (LC30) applied alone or in combination with 0.05% organosilicone was used to treat second instar larvae of C. nipponensis; thereafter, its effects on the growth, development, longevity, reproduction, and predatory ability of C. nipponensis were evaluated The results demonstrated that the organosilicone Silwet L-77 reduced the LC50 and LC30 of imidacloprid to 6.09 (95% CI: 2.31-9.42) and 10.95 mg/L (95% CI: 8.16-13.63), respectively, and enhanced imidacloprid toxicity to C. nipponensis, as reflected by the resulting extension of the growth and developmental period, reduction in female longevity, and inhibition of reproduction. When applied alone or in combination with an organosilicone, imidacloprid reduced the consumption of Corcyra cephalonica eggs by C. nipponensis. The functional response of C. nipponensis treated with imidacloprid alone or in combination with organosilicone was type II. Concomitantly, the attack rate was reduced and the handling time of prey increased., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Hawthorn spider mite, Amphitetranychus viennensis Zacher, is an economically important arthropod pest for fruit trees and woody ornamental plants. Extensive and repetitive use of synthetic acaricides has led to the development of resistance in A. viennensis . To understand the molecular basis of pesticide resistance, and to develop genetic-based control alternatives (e.g., RNAi-based biopesticides), a standardized protocol for real-time quantitative reverse transcription PCR (RT-qPCR) is needed. In the proceeding phase of this research, we screened for the internal references for RT-qPCR analysis from a pool of A. viennensis housekeeping genes under the intrinsic conditions, including developmental stage, sex, and diapause. Here, we continued our efforts to search for the reference genes under an array of extrinsic conditions, including temperature, humidity, photoperiod, host plant, and dietary RNAi. The stability of these candidate reference genes was investigated using geNorm, NormFinder, BestKeeper, and ΔCt method, respectively. Finally, RefFinder, a statistical platform integrating all four algorisms, provided a comprehensive list of genes for each extrinsic condition: (1) EF1A , α -tubulin and Actin3 were the best candidates for temperature, (2) GAPDH , 18S , and Actin3 were the most stable genes for humidity, (3) V-ATPase B , Actin3 , and 18S were the top reference genes for photoperiod, (4) GAPDH , V-ATPase B , and α -tubulin were recommended for host plants, and (5) GAPDH , V-ATPase B , and RPS9 were the top choices for dietary RNAi. Overall, V-ATPase B , GAPDH , and Actin3 were the most commonly selected reference genes in A. viennensis regardless of the experimental conditions, including both intrinsic and extrinsic. Information present here lays the foundation for the genomic and functional genomic research in A. viennensis ., (Copyright © 2020 Yang, Zhang, Zhao, Gao, Liu, Zhang, Fan, Zhou and Fan.)

Hawthorn spider mite, Amphitetranychus viennensis Zacher, is one of the most devastating pests of deciduous fruit trees. The overall goal of this research is to develop a standardized protocol for real-time quantitative reverse transcription PCR (RT-qPCR) analysis in A. viennensis following the MIQE (minimum information for publication of Quantitative real time PCR experiments) guidelines. Based on the previous knowledge, we hypothesized that internal references for RT-qPCR analysis reside in housekeeping genes (HKGs). To test this hypothesis, we examined the stability of nine HKGs from A. viennensis , including 18S ribosomal RNA ( 18S ), 28S ribosomal RNA ( 28S ), Elongation factor 1-alpha ( EF1A ), Actin3 , V-ATP vacuolar-type H + -ATPase ( V-ATPase ), α -tubulin (α -tubulin ), Ribosomal protein L13 ( RPL13 ), 40S ribosomal protein S9 ( RPS9 ), and Glyceraldehyde 3-phosphate dehydrogenase ( GAPDH ). The expression profile of these candidates under intrinsic conditions was evaluated by a panel of computational programs, including geNorm, Normfinder, BestKeeper, and ΔCt method. Based on RefFinder, a comprehensive software integrating all four above-mentioned algorithms, V-ATPase , Actin3 , and GAPDH are the top three reference genes, which are stably expressed across all the intrinsic conditions, including developmental stage, sex, and diapause. In addition, we compared reference genes recommended for different developmental stages among the nine cell-content feeding arthropods, including four spider mites, A. viennensis, Tetranychus urticae, Tetranychus cinnabarinus , and Panonychus citri , and five hemipterans, Myzus persicae, Aphis gossypii, Toxoptera citricida, Lipaphis erysimi , and Sogatella furcifera . Not surprisingly, rRNAs and ribosomal proteins, the most abundant RNA species, is the top choice, and follows by EF1A, Actin, GAPDH , and tubulin. Information present here lays the foundation for the genomic and functional genomic research in cell-content feeding arthropods in general and A. viennensis in particular., (Copyright © 2019 Yang, Gao, Liu, Lu, Zhang, Zhang, Fan, Zhou and Fan.)