Stink bugs (Hemiptera: Pentatomidae) are economic pests of cotton and soybean. This study was conducted to examine predation on stink bugs by arthropod predators in cotton and adjoining soybean habitats. Gut-content analysis based on polymerase chain reaction (PCR) was used to detect stink bug deoxyribonucleic acid (DNA) in predators collected from both crops over a 5 wk period. Nezara viridula (L.), Euschistus servus (Say), Chinavia hilaris (Say), and Euschistus quadrator Rolston were detected on soybean and cotton. Piezodorus guildinii (Westwood) and Thyanta custator custator (F.) were detected only on soybean whereas Euschistus tristigmus (Say) was detected only on cotton. Over both crops, 13 predators screened positive for a variety of stink bug species DNA by PCR analysis: Geocoris punctipes (Say) and Geocoris uliginosus (Say) (Hemiptera: Geocoridae), Orius insidiosus (Say) (Hemiptera: Anthocoridae), Hippodamia convergens Guérin-Méneville, Harmonia axyridis (Pallas) (cotton), and Scymnus sp.... Resumen Los chinches (Hemiptera: Pentatomidae) son plagas económicas de algodón y soja. Se realizó este estudio para examinar la depredación sobre chinches de depredadores artrópodos en los hábitats del algodón y soja adyacentes. Se utilizó el análisis del contenido del estómago basado en la reacción en cadena de la polimerasa (PCR) para detectar el ácido desoxirribonucleico (ADN) del chinche en los depredadores recolectados de ambos cultivos durante un período de 5 semanas. Se detectaron Nezara viridula (L.), Euschistus servus (Say), Chinavia hilaris (Say), y Euschistus quadrator Rolston en la soja y el algodón. Se detectaron Piezodorus guildinii (Westwood) y Thyanta custator custator (F.) sólo en la soja mientras que se detectó Euschistus tristigmus (Say) sólo en el algodón. De ambos cultivos, 13 depredadores examinados fueron positivos para el ADN de una variedad de especies de chinches por el análisis de PCR: Geocoris punctipes (por ejemplo) y Geocoris uliginosus (Say) (Hemiptera: Geocoridae), Orius i...
15 September 2023 in Applied Microbiology and Biotechnology
The processing of traditional Chinese medicine (TCM) is a necessary practice and usually occurs before most herbs are prescribed. According to Chinese medicine theory, raw (RDR) and stir-frying processed (PDR) Drynariae Rhizoma have different clinical applications. The purpose of this study was to establish HPLC fingerprints coupled with chemometric methods to evaluate the differences between RDR and PDR. Multivariate chemometric methods were applied to analyze the obtained HPLC fingerprints, including hierarchical cluster analysis (HCA), principle components analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results indicated that RDR and PDR samples showed a clear classification of the two groups, and seven chemical markers having great contributions to the differentiation were screened out. The findings suggested that 5-hydroxymethyl-2-furaldehyde (5-HMF) with a variable importance in the project (VIP > 1) can be used to differentiate between RDR and PDR. Moreover, 5-HMF, naringin, and neoeriocitrin were determined to evaluate their contents in RDR and PDR. The chemometrics combined with the quantitative analysis based on HPLC fingerprint results indicated that stir-frying processing may change the contents and types of components in Drynariae Rhizoma. These changes are probably responsible for the various pharmacological effects of RDR and PDR.
Toxin complex a (Tca), a high molecular weight insecticidal protein complex produced by the entomopathogenic bacterium Photorhabdus luminescens, has been found to be orally toxic to both the Colorado potato beetle, Leptinotarsa decemlineata, and the sweet potato whitefly, Bemisia tabaci biotype B. The 48 hour LC50 for Tca against neonate L. decemlineata was found to be 2.7 ppm, and the growth of 2nd instar L. decemlineata exposed to Tca for 72 hours was almost entirely inhibited at concentrations above 0.5 ppm. B. tabaci was highly susceptible to Tca as well; newly emerged nymphs that were artificially fed Tca developed poorly, or not at all. Tca concentrations between 0.1 and 0.2 ppm reduced the number of nymphs reaching the second instar by 50%. In addition, a preparation of Tca missing two prominent subunits, TcaAii and TcaAiii, was found to be at least as toxic to L. decemlineata and B. tabaci as Tca itself, indicating that the activity of Tca is not dependant on the presence of these subunits at the time of ingestion.