The status of neutral insects, mosquitoes in the food of natural enemies in tea gardens

Guangjing Qian,Xueyu Song,Shang Li,Zhenxing Wang,Shoudong Bi,Xiazhi Zhou,Yunding Zou 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.4

In order to provide scientific basis for the comprehensive pest management in tea garden, the status of the main natural enemies, Tetragnatha squamata and T. maxillosa in their prey on neutral insects, mosquitoes and mayflies in tea garden from spring to summer was verified. The quantity, temporal and spatial relationships of mosquitoes, mayflies, five main pests and T. squamata, T. maxillosa were analyzed by angle cosine coefficient, temporal niche similarity coefficient and the ranges of spatial dependence of theoretical model of semivariogram in geostatistics. The assay was conducted in Huangshan large-leafed tea gardens in 2013 and 2014, Anji white tea gardens in 2014 and 2015, and, Wuniuzao and Baihaozao tea gardens. The results showed that the top three preys, Monolepta hieroglyhpica, thrips and mosquitoes, had a close relationship with two types of natural enemies. The top three preys had a close relationship with T. squamata, mayflies were the sixth. The top three prey M. hieroglyhpica, thrips and mosquitoes had a close relationship with T. maxillosa. Neutral insects, mosquitoes were the main prey of the potential natural enemies, T. squamata and T. maxillosa from March to May in tea gardens, mayflies were the fifth to sixth. There was no significant difference in the individuals of mosquitoes in different tea gardens.

Differences in the closeness of spatial relationship between Ricanidae in their prime and natural enemies in five kinds of tea gardens

Cheng Xian,Zhang Lin,Wu Xiaomeng,Xu Yue,Sun Jiazhao,Zhou Xiazhi,Zou Yunding,Bi Shoudong 한국곤충학회 2022 Entomological Research Vol.52 No.8

To identify the natural enemy species which are close to Ricanidae in spatial relationship and to provide scientific basis for biological control and reasonable protection of natural enemies, geostatistics and the angular cosine coefficient method were used to analyze the population of Ricanidae in their prime and their natural enemies in the Anji white tea garden, the Longjing43 tea garden, the Nongkangzao tea garden, the Pingyangtezao tea garden and the Wuniuzao tea garden. The spatial relationship between six natural enemies and Ricanidae was also studied. The angular cosine coefficients were normalized to obtain the intimacy index. According to the sum of the intimacy index and the serial number of the intimacy index of each natural enemy in five tea gardens, the following conclusions could be drawn: the top three natural enemies closely related to Ricanidae in spatial relationship were Clubiona reichlini, Clubiona japonicola and Misumenops tricuspidatus; at least two species of the top three natural enemies in each tea garden were the same as the top three natural enemies in the comprehensive analysis of the five tea gardens; one of the factors that determined the spatial relationship between natural enemies and Ricanidae was the ratio of the number of Ricanidae and natural enemies. The results of this study identified the spider species of natural enemies which should be rationally used and protected in the five tea gardens.

Analysis of the following effect of the natural enemies with Frankliniella intonsa in tea garden

Cheng Honghao,Chen Shiyan,Wu Xiaomeng,Xu Yue,Zhang Lin,Sun Jiazhao,Zhou Xiazhi,Zou Yunding,Bi Shoudong 한국곤충학회 2022 Entomological Research Vol.52 No.8

In order to reasonably protect and utilize natural enemies for comprehensive control of Frankliniella intonsa, a systematic investigation was conducted on F. i n t o n s a and natural enemies in tea gardens in Hefei, Anhui Province, and the spatial following effect of natural enemies on F. intonsa was studied. The semi-variogram of natural enemies and thrips was obtained by the geostatistics method, and the correlation degree between them was analyzed by the grey correlation degree analysis method. The higher the correlation degree between natural enemies and F. intonsa, the closer the relationship between natural enemies and F. intonsa was. In this study, we analyzed the relationship between 11 natural enemies of F. i n t o n s a in tea gardens from October 28, 2020 to November 20, 2020 and from August 22, 2021 to November 19, 2021. The top five natural enemies with the largest closeness index to F. intonsa in Huangshan Dayezhong tea garden are Oxyopes sertatus, Theridion octomaculatum, Plexippus setipes, Xysticus ephippiafus and Erigonidium graminicolum. The top five natural enemies with the largest closeness index to F. intonsa in Pingyang Tezao tea garden are Erigonidium graminicolum, Plexippus setipes, Xysticus ephippiafus, Oxyopes sertatus and Clubiona japonicola.Among the top five natural enemies in the two tea gardens, those in common are Oxyopes sertatus, Erigonidium graminicolum, Xysticus ephippiafus and Plexippus setipes. According to the summation of the closeness index and the sum of the serial numbers, the top five natural enemies closely related to the spatial following of F. intonsa in the tea gardens were Oxyopes sertatus, Plexippus setipes, Erigonidium graminicolum, Xysticus ephippiafus and Theridion octomaculatum. One of the factors closely related to the space of F. i n t o n s a in the same tea garden was the ratio of F. i n t o n s a to a certain natural enemy. The smaller the ratio was, the closer the following relationship was. The results of this study provide scientific basis for biological control and natural enemy protection of F. intonsa.

Prediction of peak occurrence of Dendrolimus punctatus larvae based on Bayes discriminant method

Qian Guangjing,Song Xueyu,Sun Jiazhao,Zhang Shuping,Zhou Xiazhi,Zhang Guoqing,Zou Yunding,Fang Guofei,Zhang Zhen,Yan Ping,Bi Shoudong 한국곤충학회 2020 Entomological Research Vol.50 No.8

To improve the accuracy of forecasting the peak occurrence of Dendrolimus punctatus Walker, we here used the Bayes discriminant analysis to predict this peak occurrence for the first and second generation of Dendrolimus punctatus larvae based on these data from 1983 to 2016 in Qianshan County, Anhui Province. Our present results showed that this discriminant equation for the first generation was as follows: f (1) = 3.2588-6.2700x1 + 1.2870x2 + 0.7920x3 + 0.4152x4; f (2) = 14.5215- 8.5710x1 + 2.9790x2 + 2.0280x3 + 0.5031x4; f (3) = 3.5264; f (4) = 66.8312- 12.5216x1 + 5.1740x2 + 4.7162x3 + 0.6033x4. And that the prediction accuracy for the first generation was 97.22%. Whilst this discriminant equation for the second generation was as follows: f (1) = 3.536-1.192x5 + 1.338x6 + 0.638x70.025x8; f (2) = 7.317-1.337x5 + 4.240x6 + 1.010x70.295x8; f (3) = 16.488- 3.192x5 + 4.955x6 + 1.900x7–0.411x8; f (4) = 34.502- 4.184x5 + 7.484x6 + 2.583x7–0.443x8. The prediction accuracy for the second generation was 85.71%. Overall, our findings revealed that the Bayes discriminant analysis could screen out key factors to significantly improve the prediction accuracy of peak occurrence of Dendrolimus punctatus larvae.

Evaluation of the close degree of the spatial relationship between natural enemies of tea gardens and Frankliniella intonsa based on variance analysis of cluster samples

Honghao Cheng,Shiyan Chen,Xiaomeng Wu,Yue Xu,Lin Zhang,Jiazhao Sun,Xiazhi Zhou,Yunding Zou,Shoudong Bi 한국곤충학회 2022 Entomological Research Vol.52 No.6

The aim of this paper is to clarify the difference of spatial closeness between natural enemies and Frankliniella intonsa, and to provide a scientific basis for rational protection and utilization of natural enemies. This paper applied the block-sample square difference analysis method, Gray correlation degree method, the aggregation intensity index method and ρ index method to study the difference in the closeness of the spatial relationship between F. intonsa and natural enemies when the number of F. intonsa and their natural enemies was the highest and the minimum area occupied by F. i n t o n s a individuals and colonies in five tea plantations in Hefei, Anhui province in 2021 and four tea plantations in 2020. The results were as follows: 1) Tetragnatha squamata Karsch, Xysticus ephippiafus, Erigonidium graminicolum and Theridion Octomaculatum were the top four natural enemies closely related to F. intonsa in 2021. The top three natural enemies closely related to F. intonsa in 2020 were Tetragnatha squamata Karsch, Xysticus ephippiafus and Theridion Octomaculatum. Tw o y e a r s a g o , Tetragnatha squamata Karsch and Xysticus ephippiafus were the same. 2) Cluster size did not change the distribution patterns of natural enemies and F. intonsa. 3) The aggregation of F. intonsa was caused by their own causes or some environmental factors, and the aggregation of natural enemies was caused by environmental factors. 4) In 2021, the minimum area occupied by individuals and groups of F. intonsa in tea gardens was 2m2, and in 2020, it was 8 m2.