title: Levels of Salivary Enzymes of Apolygus Lucorum (Hemiptera: Miridae), From 1st Instar Nymph to Adult, and Their Potential Relation to Bug Feeding.
abstract: In recent years, Apolygus lucorum has caused increasing damage to cotton and fruit trees in China. The salivary enzymes secreted by A. lucorum when sucking on host plants induce a series of biochemical reactions in plants, and the pre-oral digestion benefits the bug feeding. In this study, the food intake of A. lucorum from 1st instar nymphs to adults was measured, and the corresponding salivary activity of pectinase, amylase, cellulase, protease, polyphenol oxidase and peroxidase was determined. Daily food intake varied with developmental stage, peaking in 3rd and 4th instar nymphs. Pectinase, amylase, cellulase and protease were detected in both nymphal and adult saliva of A. lucorum, while neither polyphenol oxidase nor peroxidase was detected. Protease activity varied with food intake peaking at the 3rd-4th instar, and then slightly decreasing at the 5th instar. Levels of pectinase, amylase and cellulase increased significantly with the daily feeding level until the 3rd instar, corresponding with increasing damage to host plants. The activity of both cellulase and protease had a significant linear relationship with the average daily food intake. The increasing activity of enzymes in saliva explain stage-specific impacts of A. lucorum on the host plants, and suggest that optimal management of A. lucorum would be confined to its control threshold prior to the peak of daily feeding in the 3rd instar.
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Tan
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
authors.forename: Xiuping
authors.initials: X
authors.lastname: Xu
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Gao
authors.affiliation: General Station of Plant Protection of Shandong Province, Jinan, China.
authors.forename: Qinmin
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Institute of Plant Protection, Qingdao Academy of Agricultural Sciences, Qingdao, China.
authors.forename: Jiqing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Fanghao
authors.initials: F
authors.lastname: Wan
authors.affiliation: College of Agronomy and Plant Protection, Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
authors.forename: Hongxu
authors.initials: H
authors.lastname: Zhou
mesh_terms: D000681:Amylases / Q000378:metabolism; D000818:Animals; D002480:Cellulase / Q000378:metabolism; D004435:Eating; D057075:Enzyme Assays; D006430:Hemiptera / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism; D006867:Hydrolases / Q000378:metabolism*; D008018:Life Cycle Stages; D009758:Nymph / Q000201:enzymology / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D011096:Polygalacturonase / Q000378:metabolism; D012469:Salivary Glands / Q000201:enzymology
chemical_list: D006867:Hydrolases; D000681:Amylases; D011096:Polygalacturonase; D002480:Cellulase; D010447:Peptide Hydrolases