scholarly journals Evaluation of Botanicals for Management of Piercing–Sucking Pests and the Effect on Beneficial Arthropod Populations in Tea Trees Camellia sinensis (L.) O. Kuntze (Theaceae)

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Yueyue Tian ◽  
Zejun Chen ◽  
Xiaoqin Huang ◽  
Lixia Zhang ◽  
Zhengqun Zhang

Abstract The tea green leafhopper Empoasca onukii Matsuda (Hemiptera: Cicadellidae), the orange spiny whitefly, Aleurocanthus spiniferus (Quaintanca) (Hemiptera: Aleyrodidae), and the green plant bugs Apolygus lucorum Meyer-Dür (Hemiptera: Miridae) are the important piercing–sucking herbivores in tea trees Camellia sinensis (L.) O. Kuntze (Theaceae). The goal of this study was to evaluate the laboratory toxicities and field control efficacies of botanical insecticides including matrine, azadirachtin, veratrine, and pyrethrin to three tea pests. Via leaf-dip bioassay, toxicity tests with botanical insecticides indicated that there were significant differences between the LC50 values for botanical insecticides within the same insect species. Matrine had the highest toxicity to E. onukii, A. spiniferus, and A. lucorum with the LC50 values of 2.35, 13.10, and 44.88 mg/liter, respectively. Field tests showed that, among four botanical insecticides, matrine at dose of 9 g a.i. ha−1 can significantly reduce the numbers of E. onukii and A. spiniferus and the infestation of A. lucorum on the tea plants. Furthermore, botanical insecticides matrine and azadirachtin had no obvious influence on the coccinellids, spiders, and parasitoids densities in tea plantations. The results of this study indicated that use of botanical insecticides, such as matrine, has the potential to manipulate the population of E. onukii, A. spiniferus, and A. lucorum and will be an effective and environmentally compatible strategy for the control of tea pests.

2015 ◽  
Vol 55 (4) ◽  
pp. 362-370 ◽  
Author(s):  
Zhengqun Zhang ◽  
Xuefeng Zhang ◽  
Feng Liu ◽  
Wei Mu

Abstract The green plant bug (Apolygus lucorum Meyer-Dür) is a key pest of Bt cotton in China. Along with biological control, chemical control is one of the most important strategies in A. lucorum Integrated Pest Management (IPM). The goal of this study was to evaluate the toxicity of eight conventional insecticides to A. lucorum and to assess the susceptibility of two generalist predators Chrysopa sinica (Jieder) and Propylaea japonica (Thunbery) to insecticides that are commonly used in A. lucorum management. Via glass-vial and leaf-dip bioassay, toxicity tests with selected insecticides at two different life-stages of A. lucorum indicated significant differences between the LD50 or LC50 values for these compounds within different insecticidal classes. Phenylpyrazole fipronil had the highest toxicity to 4th-instar nymphs and adults of A. lucorum, whereas neonicotinoid imidacloprid had the lowest toxicity among the insecticides. Females were more tolerant to insecticides than were males, as shown by the higher LD50 values for females. Furthermore, laboratory tests showed that endosulfan had the highest selectivity to C. sinica and P. japonica: the selective toxicity ratios (STRs) were superior to other tested insecticides, particularly imidacloprid, and were 5.396 and 4.749-fold higher than baseline STRs, respectively. From this study, we conclude that fipronil can potentially be used to efficiently control A. lucorum. An alternative control agent worth consideration is endosulfan, owing to its relative safety to non-targeted natural enemies.


Insects ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 167 ◽  
Author(s):  
Yueyue Tian ◽  
Hanyue Wang ◽  
Jian Hou ◽  
Lixia Zhang ◽  
Zhengqun Zhang ◽  
...  

The mirid bugs are one of the most important piercing–sucking insect pests in tea plantations, which severely reduce the quality and economic benefits of tea. In this study, the mirid bug species in the three tea-producing areas in Shandong Province of China were investigated. The distribution and occurrence of dominant species of mirid bugs on four weed host plants and tea plants Camellia sinensis (L.) O. Kuntze (Theaceae) were also studied in the tea agro-ecosystems. The results showed that Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) was the dominant mirid bug species in the tea growing areas. Apolygus lucorum densities on Humulus scandens (Lour.) (Moraceae) and Artemisia lavandulaefolia DC. (Asteraceae) were relatively higher than those on Conyza canadensis (Linn) Cronq (Asteraceae), Artemisia annua Linn (Asteraceae), and C. sinensis. Host plant switching of A. lucorum in the tea agro-ecosystem was: A. lucorum scattered on and seriously infested tea plants in June and July; A. lucorum largely migrated to and gathered on H. scandens, A. lavandulaefolia, C. canadensis, and A. annua at the flowering stage, and population densities of A. lucorum on these flowering hosts peaked in late September; in October, A. lucorum gradually moved back to flowering tea plants. These results could provide a reference for selecting host plants, such as Artemisia plants, as trap plants for sustainable control of mirid bugs in tea plantations.


Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2786-2797 ◽  
Author(s):  
Shuangshuang Wang ◽  
Xiaozeng Mi ◽  
Zhiran Wu ◽  
Lixin Zhang ◽  
Chaoling Wei

Gray blight disease, caused by Pestalotiopsis-like fungi, is one of the deadliest threats to tea (Camellia sinensis) production. However, little information is known about the traits and characteristics of this pathogen. Here, a systematic survey was performed, and a total of 20 representative isolates were obtained from the leaves of tea plants affected by gray blight in two main tea plantations located in Anhui Province, China. Further analyses showed that two isolates were identified as Neopestalotiopsis ellipsospora, three isolates were regarded as Pseudopestalotiopsis chinensis, one isolate was considered as Pseudopestalotiopsis camelliae-sinensis, and the remaining isolates belonged to Pseudopestalotiopsis spp., on the basis of morphological characteristics and multigene phylogenetic analyses of the internal transcribed spacer, β-tubulin, and translation elongation factor 1-α. Pathogenicity tests indicated that there were significant differences in virulence among the Neopestalotiopsis and Pseudopestalotiopsis isolates when inoculated on the leaves of the tea plant (C. sinensis ‘Shuchazao’). Furthermore, varied pathogenicity was also observed for the same isolate when inoculated on different varieties of tea plants. To our knowledge, this is the first record of Neopestalotiopsis ellipsospora and Pseudopestalotiopsis chinensis causing gray blight disease of tea plants in China.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peixian Bai ◽  
Liyuan Wang ◽  
Kang Wei ◽  
Li Ruan ◽  
Liyun Wu ◽  
...  

Abstract Background Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized. Results The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg). Conclusions Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production.


2010 ◽  
Vol 45 (3) ◽  
pp. 387-393 ◽  
Author(s):  
Yanhui Lu ◽  
Kongming Wu ◽  
Kris A. G. Wyckhuys ◽  
Yuyuan Guo

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1640-1646 ◽  
Author(s):  
Fei Xiong ◽  
Jieren Liao ◽  
Yuanchun Ma ◽  
Yuhua Wang ◽  
Wanping Fang ◽  
...  

Camellia sinensis cultivars were treated with 5 mm putrescine (Put) under a range of sodium chloride (NaCl) concentrations. Plant performance, as indicated by various indicators associated with plant growing condition such as photosynthetic parameters and polyamine (PA) contents, especially the content of Put, was improved by the treatment. The extent of both Na+ accumulation and K+ loss increased. The activity levels of the antioxidant enzymes related to salt stress, such as superoxide dismutase (SOD), peroxidase (POD), and catalase, were significantly altered with different salt stress levels and showed a decrease in the general trend. Besides, tea polyphenols, the tea quality indicator, increased during the salinity treatment but decreased when we applied Put. These findings suggest that treatment with Put might constitute an effective means for alleviating salinity stress–induced injury through its positive effect on photosynthetic efficiency and for controlling reactive oxygen species (ROS) scavenging ability under appropriate salt stress levels.


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