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Background: The tea green leafhopper, Empoasca flavescens is the most important pest of tea plants in China. Mymarid attractants based on herbivore-induced plant volatiles (HIPVs) from leafhopper feeding and oviposition-induced plant volatiles (OIPVs) were formulated and tested as a novel pest control agent against the leafhopper in tea plantations., Results: Results showed that two mymarid species, Stethynium empoascae and Schizophragma parvula, had a reducing effect on leafhopper populations. The HIPVs and OIPVs were identified and bioassayed to screen the key synomones showing strong attraction to the mymarids. They were formulated into different blends, of which Field Attractant 1, comprising linalool, methyl salicylate, (E)-2-hexenal, perillen and α-farnesene at ratio of 1:2:3:58:146 (20 mg/lure), showed the strongest attraction to the mymarids. In field trials with the attractant, the average parasitism rate (60.46 ± 23.71%) of tea leafhoppers by the two mymarids in the attractant-baited area was significantly higher than that (42.85 ± 19.24%) in the CK area. Also, the average leafhopper density (46 ± 30 per 80 tea shoots) in the attractant-baited area was significantly lower than that (110 ± 70 per 80 tea shoots) in the CK area., Conclusion: This study showed that a synthetic blend of key volatiles from HIPVs and OIPVs at an optimal ratio can be formulated into an attractant with the potential to attract and retain wild mymarid populations to suppress leafhopper populations in infested tea plantations, so as to reduce or avoid the spraying of insecticides. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Background: The tea green leafhopper, Empoasca flavescens is the most important pest in Chinese tea plantations. For decades its control has been executed almost exclusively through pesticide applications. A semiochemical-based 'push-pull' strategy was tested on the leafhopper in the study., Results: The odors released from Tagetes erecta and Flemingia macrophylla significantly repelled and attracted leafhoppers, respectively. These volatile compounds (46 from T. erecta and 53 F. macrophylla) were identified and quantified via gas chromatography-mass spectometry (GC-MS) analysis. Y-tube olfactometer assays indicated that thymol anisole, thymol and camphor had significant repellent effects on the leafhoppers, resulting in a ternary repellent blend at a 4:3:13 ratio. Cis-3-hexen-1-ol, cis-3-hexenyl acetate, nonanal and α-farnesene were significantly attractive to the leafhoppers, making an attractant blend at a 17:4:1:1 ratio. In the field, the push-pull strategy with the repellent dispensers placed within the tea bushes and the attractant-baited sticky traps hung 15 cm above the tea plants showed a significant control efficacy, reaching 69% and 55% at two and 14 days post-treatment, respectively, similar to those in the insecticide control plots. Additionally, the leafhopper density in the push-pull intercropping plot was 63.2 leafhoppers/100 tea shoots/visit, much lower than those in the pull intercropping plot and nonintercropping plot., Conclusion: Application of the push-pull strategy using both synthetic repellent and attractant, or intercropping T. erecta and F. macrophylla with tea plants, can effectively reduce the leafhopper population. This approach might have great potential as an environmentally safe control strategy against the leafhopper. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

The complete mitochondrial genome of Tambocerus sp. (Hemiptera: Cicadellidae) from Zhejiang and Anhui provinces of China was sequenced. The total length of the mitogenome is 15 955 bp (GenBank accession no. KT827824) and consists of 22 transfer RNAs, 13 protein-coding genes, 2 ribosomal RNAs and 1 control region. The base composition of the heavy strand for A, T, C, and G is 41.39, 35.02, 14.00, and 9.59%, respectively. All of the protein-coding genes (PCGs) start with ATN. Five protein-coding genes use TAA as stop codons, four use TAG as stop codons, and others use incomplete stop codons ''T--'' or ''TA-''. The control region has a length of 1581 bp which is between rrnS and trnI genes with the AT content high to 85.96%. Phylogenetic analysis indicated that Tambocerus sp. was clustered in a closely related subgroup with Homalodisca vitripennis and Empoasca vitis. This is consistent with the result of the traditional taxonomy.

The complete mitochondrial genome of Empoasca vitis was sequenced. The length of the mitogenome is 15,154 bp with 78.35% AT content (GenBank accession No. KJ815009). The genome encode 37 typical mitochondrial genes including 22 transfer RNA genes, 13 protein-coding genes, 2 ribosomal RNA genes and an A+T-rich region. The gene arrangement is similar to that of Drosophila yakuba, the presumed ancestral insect mitochondrial gene arrangement. Except for cox2 using GTG as start codon, other protein-coding genes (PCGs) share the start codons ATN. Usual termination codon TAA and incomplete stop codon T are using by 13 protein-coding genes. The A+T-rich region has a length of 977 bp with the AT content high to 88.95%.

The tea aphid, Toxoptera aurantii Boyer ( Hemiptera: Aphididae), is a major pest of the tea plant, Camellia sinensis ( L.) O. Kuntze ( Theaceae). The attraction of the aphids to different colors and volatile compounds from tea shoots was investigated. Fourteen compounds were identified using gas chromatography-mass spectrometry from headspace samples of intact tea shoot volatiles ( ITSV). Electrophysiological and behavioral responses of winged tea aphids to ITSV as well as to the full blend of 14 synthetic compounds, to a partial mixture of green leaf volatiles ( GLV) included in the 14 compounds, and to individual synthetic compounds were studied by using electroantennography ( EAG) and a Y-tube olfactometer. The various tea volatiles and blends were strongly active, with ITSV being the strongest. In the greenhouse and in tea plantations, sticky boards of six different colors strongly attracted tea aphids in flight, with 'rape-flower yellow' and 'Chinese olive-yellow-green' being the most attractive. Furthermore, these two boards in combination with ITSV attracted winged tea aphids more strongly than their corresponding colored sticky boards alone. In the greenhouse, plastic models of tea seedlings baited with ( Z)-3-hexen-1-ol or the GLV mixture significantly attracted winged tea aphids in flight. This study demonstrates that green leaf volatiles from tea shoots are attractive to the tea aphid. The combination of these volatiles with the color light yellow or green, and the shape of tender tea shoots result in orientation flight and landing of winged tea aphids on host tea shoots. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome ofEmpoasca vitiswas sequenced. The length of the mitogenome is 15,154 bp with 78.35% AT content (GenBank accession No. KJ815009). The genome encode 37 typical mitochondrial genes including 22 transfer RNA genes, 13 protein-coding genes, 2 ribosomal RNA genes and an A+T-rich region. The gene arrangement is similar to that ofDrosophila yakuba, the presumed ancestral insect mitochondrial gene arrangement. Except forcox2using GTG as start codon, other protein-coding genes (PCGs) share the start codons ATN. Usual termination codon TAA and incomplete stop codon T are using by 13 protein-coding genes. The A+T-rich region has a length of 977 bp with the AT content high to 88.95%. [ABSTRACT FROM AUTHOR]