This paper reviews the taxonomy and biology of the family Macrochelidae in China, with a special focus on the taxonomy and their role as predators of pests in biological control. A checklist with distribution data of 37 species in four genera is provided.
One new species of the genus Parabonzia Smiley and one new species of Neoscirula Den Heyer are described and illustrated. Parabonzia zhangi sp. nov. was found in soil in a hole in the tree Platanus hispanica Muenchh in Yichang city, Hubei province, while Neoscirula saitoi sp. nov. was collected on the bark of P. hispanica in Shunchang county, Fujian province. Types were deposited in the collection of Plant Protection Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China.
Schizotetranychus nanjingensis Ma & Yuan is a mite pest injurious to the giant bamboo (Phyllostachys pubscens) in Fujian, China. The predatory mite Amblyseius longispinosus was explored as a potential biocontrol agent against S. nanjingensis in a series of experiments. Functional response experiments at six different temperatures showed that handling time (Th) generally decreased with temperature, whereas successful attack rate (a) increased with temperature and levelled off at >20° (Table 2). Judging by a/Th values, A. longispinosus was most efficient against S. nanjingensis at 30-35°C, about half as efficient at 20 and 25¡C and performed poorly at 10-15°C. The rate of oviposition increased linearly with prey density. As expected, the number of eggs laid by predators increased linearly with the number of prey they consumed. With a fixed number of prey available, predation rates per predator decreased with predator density. The potential of A. longispinosus as a biocontrol agent against A. nanjingensis is discussed.
This paper dealt with the studies on outbreaks phenomenon of pest mites of moso bamboo (Phyllostaychs pubescens) forests in south of China. The result showed that the total pest mites in monoculture forests was on an average 289.29% as high as that in polyculture stands. Thphlodromus bambusae Ehara, a natural enemy, in the polyculture forests was on an average 262.5% as high as that in the monoculture. The proportion of pest mites and nature enemy in the monoculture forests was on an average 1∶118,but in the polyculture was on an average 1∶13. The result from these research showed that the outbreaks of pest mites in bamboo forests was caused by fatal disruption of the stable interaction between predators and their 3 prey species in the fields through farming activity such as removal of the plants under bamboo forests. For example, the population of Schizotetranycus nanjingensis Ma Yuan had been regulated by T. bambusae, where another spider mite species S. miscanthi Saito in the host plant (Miscanthus sp.) is very important prey species for keeping the population of T. bambusae. Monoculture may reduce the abundance of natural enemies of phytophagous mites by reducing alternative habitats and food for them, which indirectly contribute to the outbreake of pest mites on bamboo in Fujian Province.
This paper reviews the research on the systematics and biology of the superfamily Bdelloidea in China, with an updated checklist of 48 species belonging to 16 genera in the family Cunaxidae and 26 species belonging to nine genera in the family Bdellidae. Important contributions to the Chinese fauna of the Bdellidae were made by Tseng Yi-Hsiung (Taiwan), Hong Mei (former with Fudan University in Shanghai) and Lin Jian-Zhen (and colleagues in Fujian Academy of Agricultural Sciences, Fuzhou), and those to the Cunaxidae by Tseng Yi-Hsiung, Li Long-Shu (and colleagues in Southwest University, Chongqing) and Lin Jian-Zhen (and colleagues). There have been relatively few studies on the biology and use in biological control of the Bdelloidea in China, and these are briefly reviewed.
Background: The genomic mutation features of primary liver cancer (PLC) varied from various pathology and etiology. Alterations in DNA damage repair (DDR) genes could induce genomic instability and accumulate tumor mutation burden (TMB), which was related to the efficacy of immune-checkpoint blockade treatment. However, the characteristics of DDR gene alterations and its association with TMB in PLC remain largely undefined.Method: We enrolled 357 Chinese PLC patients as training cohort and used the TCGA-LIHC data of 373 hepatocellular cancer patients as validation cohort. FFPE tumor tissues and matched blood samples were collected from these Chinese patients for next-generation-sequencing (NGS)-based 450 genes panel assay, which contains 35 DDR genes. All histological diagnoses were confirmed by independent pathologists. Correlation of the DDR pathway genes alterations with TMB was assessed by multiple linear regression model using R package "nlme". The receiver operating characteristic (ROC) curve was applied to determine the diagnostic efficiency of DDR pathway genes for TMB high (which was defined as the top quantile) using R package "pROC".Results: The training cohort of Chinese PLC patients included 282 males and 75 females with the mean age of 56.3 years old. The pathologic subtypes include 214 hepatocellular carcinoma (HCC), 122 intrahepatic cholangiocarcinoma (ICC) and 21 mixed hepato-cholangiocellular carcinoma (H-ChC). There are 25.8% (92/357) patients had at least one DDR gene alteration. The DDR mutation rate showed no significant differences among three subtypes of PLC (HCC vs ICC vs H-Chc: 22.9% (49/214) vs 30.3% (37/122) vs 28.6% (6/21), P=0.311). In addition, 16.3% (15/92) of the patients with DDR gene mutations have germline variations. The TMB in HCC patients was significantly higher than that in ICC patients but not in H-ChC patients (median TMB for HCC, ICC and H-ChC was 5.4, 3.1, and 3.9 Muts/Mb, Kruskal-Wallis test, P<0.001). Importantly, PLC patients with DDR gene mutations had significantly higher TMB compared to patients without DDR gene mutation (6.2 vs 3.9 Muts/Mb, P<0.001), which was further validated in TCGA-LIHC data (95 vs 64 mutations, P<0.001). The patients with germline DDR gene mutations had significant lower TMB compared with patients with somatic DDR gene mutations (3.1 vs 6.3 Muts/Mb, Wilcox test, P=0.041). We further defined 3 subtypes of DDR pathways (BER, FA and MMR) that significantly correlated with TMB in the training cohort, which exhibited diagnostic efficiency in distinguishing TMB-high or TMB-low PLC in TCGA-LIHC dataset (AUC: 0.67).Conclusion: DDR gene alterations were significantly positively associated with TMB in PLC. Mutations occurred in BER, FA or MMR pathways indicated higher TMB in PLC, which have the potential to serve as markers to predict the TMB level to guide the immune-checkpoint inhibitor therapy.Citation Format: Jianzhen Lin, Honglin Guo, Junping Shi, Xu Yang, Yan Jiang, Yi Bai, Junyu Long, Dongxu Wang, Jin Bian, Ming Yao, Kai Wang, Haitao Zhao. Alterations of DNA damage repair genes in Chinese primary liver cancer patients and its association with tumor mutation burden [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1700.
Aponychus corpuzae is a pest of bamboo in Fujian, China. The predatory mite Amblyseius longispinosus was explored as a potential biocontrol agent against Ap. corpuzae in a series of experiments on its predation on Ap. corpuzae. The rate of prey consumption (per predator female) increased linearly with temperature from 1.35 at 15°C to 5.22 at 35°C (the relationship can be described by Y = -1.005 + 0.185 T; R = 0.96), whereas the rate of oviposition increased with temperature from 0.11 at 15°C to 3.58 at 30°C and then decreased to 2.27 at 35°C [the relationship can be described by Y = 0.141 (T-30)2 + 43]. The rate of predation increased linearly with prey density within the range of 1-9 prey per leaf (Y = 0.805 + 0.418 X, R = 0.96) and reached a plateau at the density of 9 prey per leaf, but the rate of oviposition increased linearly with prey density Y = 0.955 + 0.380 X (R = 0.97). As expected, the number of eggs laid by predators increased linearly with the number of prey they consumed (Y = 0.290 + 0.423 X; R = 0.93); on average, a predator consumed 1.3-2.5 prey to lay 1.0-1.5 eggs. Functional responses of predator to prey density at five different temperatures (15, 20, 25, 30 and 35°C) and to different active life stages of spider mites (larva, protonymph, deutonymph, adult female and adult male) approximated Holling type II. Amblyseius longispinosus was considered more effective against spider mites at 25°C than at other temperatures. They are most effective against adult female spider mites but least effective against spider mite larvae. With a fixed number of prey available, predation rates per predator decreased with predator density. Aponychus corpuzae adults were observed to show defensive behaviour against predators at high prey densities.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
