Analysis of composition and succession characteristics of apple pests based on bibliometrics in China

Abstract:【Objective】Apple industry is of great significance to China’s economy, resident consump- tion and ecological protection, etc. With the development of the apple industry, growing techniques, cul- tivation models, and pest management related to apple production have undergone major changes. Apple pests were associated with the apple production, and the species composition as well as quantity characteristics also changed accordingly. With the development of apple industry in recent years, there are obvious changes in apple cultivation and plant protection techniques. Taking apple pest management as an example, the types of pesticides have increased and pesticides have been replaced frequently, and other prevention and control measures have also been greatly improved. How did the pests respond to these changes? To understand their composition and succession characteristics is helpful to make out relevant control strategies, breeding, and cultivation directions.【Methods】In this paper, based on CNKI (China National Knowledge Infrastructure) as the data source, the theme“Apple insect pests”was used as the search term. The searching year was limited to 2019 and earlier, and the literatures on controlling and prevention of apple pests were selected. Information about apple insect pests’species, times and location were analyzed, which were involved in the literature, and the reported apple pests were classified according to their feeding habits, namely, piercing-sucking injurious, trunk boring, defoliatorand fruit boring pests. Different types of apple pests were analyzed according to the frequency of their literatures in different periods. The apple pest species were analyzed and a number of related apple pests and the number in related literatures were compared to study the succession characteristics of pest species. Af- ter screening out, a total of 672 valid documents and a total of 94 insect pests were obtained. The 94  pest species were used as keywords to retrieve in the CNKI data base. In order to prevent different names of the same species from being missed, the advanced search method was chosen, two or more names were searched in a related manner. The selected apple pests’literatures were sorted according to the publication times. The top ten pests of different types were selected to study the research and focus trends.【Results】There were 94 species of apple pests belonging to 8 orders and 48 families, mainly Lepidoptera pests, followed by Coleoptera and Hemiptera. The characteristics of apple pests were: before 1980, defoliator pests were the research focus followed by piercing-sucking injurious pests; from 1981 to 1989, the proportion of defoliator pests decreased, the proportion of fruit boring pests increased significantly, and piercing-sucking injurious pests increased slightly. During 1990-2019, the proportion of the defoliator pests were basically constant, and the number of fruit boring pests increased, although the number of piercing-sucking injurious pests’literature was decreasing, but it was still the research fo- cus of four major types of pests. No significant changes were found in the number of pest species by time, mainly concentrating on several important apple pests. Taking the literature of pest species as a statistical data sources, it was found that its research characteristics were different from the former. The number of piercing-sucking injurious pests was increasing with time; the number of trunk boring pests was basically constant; the number of defoliator pests decreased with time before 2000, and it was basi- cally stable after 2000. The characteristics of fruit boring pests were increasing before 2000, though it was declined after 2000, the number was still the highest among the four types of pests. Among the bor- ing pests, literatures on cotton bollworm were the highest and reached a peak around 2000. Literatures on oriental fruit moth, peach fruit borer, peach borer, except the codling moth decreased slightly in 2000, and all showed an upward trends, and reached a peak in 2010—2016. Among the main piercing- sucking injurious pest groups, the number of pest mites were the largest, followed by green leaf bug, aphids and giant mealy bug, and apple yellow aphids showed a slight decrease in 2000, with an increase later. The main defoliator pests were Asiatic apple leaf miner and the small leaf-rolled moth of the apple, which increased gradually with the year, and after 2014, the literature number began to decrease. Among the apple trunk boring insect, the literatures on mulberry longicorn and Anoplophora chinensiswere the largest, the literature of Agrilus mali Matsumura has increased since 2000.【Conclusion】The main species of apple pests changed with time, and the number of pest species did not change signifi- cantly. However, the species composition of pests showed obvious succession, the number of defoliator pests decreased and the number of piercing-sucking pests increased, the piercing-sucking pests were the main current or the future control target. At present, research on apple insect pests was mainly concen- trated on several major pests. Some quarantine pests may expand the distribution areas and aggravate in the future. This research is of great significance for making and guiding the prevention and control of apple pests.