Journal of Asia-Pacific Entomology 21 (2018) 417–422

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Journal of Asia-Pacific Entomology

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The seasonal detection of AcSBV (Apis cerana sacbrood virus) prevalence in T

Yu-Shin Naia, Chong-Yu Koa, Pei-Shou Hsub, Wen-Shi Tsaic, Yue-Wen Chena, Meng-Hao Hsud, ⁎ I-Hsin Sungc, a Department of Biotechnology and Animal Science, National Ilan University, Yilan, Taiwan, ROC b District Agricultural Research and Extension Station, Council of Agricultural, Executive Yuan, Miaoli, Taiwan, ROC. c Department of Plant Medicine, National Chiayi University, Chiayi 60004, Taiwan, ROC d Division of Forest Protection, Taiwan Forestry Research Institute, 10066, Taiwan, ROC

ARTICLE INFO ABSTRACT

Keywords: The epizootic disease caused by Apis cerana sacbrood virus (AcSBV) occurred in Eastern hive bee, A. cerana, since Apis cerana sacbrood virus 2015 in Taiwan. A large-scale survey of this disease from September and December 2016 in Taiwan was per- AcSBV formed including symptom check and molecular identification in honey bees of A. cerana hives and several A. Prevalence mellifera hives, which were co-cultured with A. cerana. Based on the nucleotide sequences of partial VP1, the Taiwan phylogenetic analysis with those of the known AcSBV isolates revealed that most of AcSBV isolates from Taiwan were closely relative to SBV-FZ and -JL isolates from China, whereas only one sample (N15-5-1) was in a distinct cluster, which was closely relative to SBV-LN from China too. The AcSBV prevalence was occurring in A. cerana hives in most areas of Taiwan except for those in Hualien and Pingtung Counties in Taiwan. Notably, the AcSBV prevalence rate showed the temporal increase from 47.1% to 69.6% within 4 months. In addition, 37.5% of AcSBV prevalence rate was found in A. mellifera hives. It showed that A. mellifera was also susceptible to AcSBV infection. The present results would provide the information on the epidemiology and for prospective research.

Introduction et al., 1986; Verma et al., 1990; Kim et al., 2008). SBV is a single- stranded, positive-sense RNA virus, which is belonging to the Iflaviridae Honey bees are vital pollinators for wildlife plants and agriculture (King et al., 2012). SBV could be identified by the special symptom of crops (Klein et al., 2007). The Eastern hive bee, Apis cerana Fabricius, is death deformed larvae in the hives, which had fluid-filled sacs and a common honey bee species in Asian countries, its original distribution sometimes with slightly sour smell. There are many studies described ranged from East to Southeast Asia (Oldroyd and Wongsiri, 2006). that A. cerana was susceptible to SBV and had a high virulence (Bailey, Western honey bee, Apis mellifera Linnaeus, was cultured for a long time 1969; Yan et al., 2009; Gong et al., 2016). SBV infection usually caused in Asian countries (Crane, 1999). Both A. cerana and A. mellifera species a large amount of A. cerana larvae death and even led to the whole have a great contribution in commercial utilizations of honey harvest colony losses occurred in China, India, South Korea, Thailand, and and relevant as important pollinators in the Asian ecosystem (Crane, Vietnam (Rana et al., 1986; Verma et al., 1990; Kim et al., 2008; Ma 1999; Oldroyd and Wongsiri, 2006). In most Asian areas, two species of et al., 2011; Nguyen and Le, 2013). However, the infection of SBV is not honey bee are co-cultured in apiaries. usually resulting in A. mellifera colony losses, due to its different viru- Recently, the decline or losses of global pollinating insects was lence between A. cerana and A. mellifera (King et al., 2012). noticed by several anthropogenic pressures (Vanbergen and The Insect Since 2016, many beekeepers in Taiwan found the SBV-like Pollinator Initiative, 2013). Of these pressures, the viral pathogens have symptom in their A. cerana colonies and the colonies were declined been known to cause serious honey bee colony losses (Manley et al., rapidly. Previous study suggested that the SBV isolates were novel to 2015). The common viral diseases were detected in both A. cerana and Taiwan (Huang et al., 2017). A government-led large-scale survey of A. mellifera colonies (Chen et al., 2004). SBV disease was then began from September to December in 2016. The Among these viruses, the sacbrood virus (SBV) infection had resulted preliminary result of molecular identification indicated that this sac- in a large amount of honey bee colonies and honey harvest losses (Rana brood disease epizootic is currently increasing in Taiwan and still

⁎ Corresponding author. E-mail address: [email protected] (I.-H. Sung). https://doi.org/10.1016/j.aspen.2018.02.003 Received 29 September 2017; Received in revised form 11 January 2018; Accepted 6 February 2018 Available online 07 February 2018 1226-8615/ © 2018 Published by Elsevier B.V. on behalf of Korean Society of Applied Entomology. Y.-S. Nai et al. Journal of Asia-Pacific Entomology 21 (2018) 417–422

Table 1 Sampling sites of Apis cerana apiaries and their results of visual symptom checks and molecular identifications.

Area-apiary Apiary scale City/ // No. of sample for AcSBV Collection month Symptomb AcSBV detection indexa (beehives) district detection resultc

E-1 < 10 Hualien County Ji'an Township 1 November Un − E-1 Ji'an Township 1 December Un − E-2 < 10 Ilan County Dongsha Township 1 November − + E-3 < 10 Dongsha Township 1 November Un + E-4 < 10 Ilan University 1 October Un − E-5 < 10 Sanxing Township 1 December Un − E-6 < 10 Taipingshan 1 November Un − E-7 < 10 Wujie Township 1 December Un − E-8 < 10 Zhuangwei Township 1 December Un − N-9 < 50 Keelung City Qidu Dist. 2 October + + N-10 < 50 Qidu Dist. 2 October + + N-11 < 50 Qidu Dist. 1 November + + N-11 Qidu Dist. 1 December + + N-12 < 10 Taipei City Shilin Dist. 1 October + + N-13 < 10 Wenshan Dist. 1 November − + N-13 Wenshan Dist. 1 December + + N-14 < 50 New Taipei City Pinglin Dist. 1 November − + N-14 Pinglin Dist. 1 December − + N-15 < 50 Shuangsi Dist. 1 November − + N-15 Shuangsi Dist. 1 December + + N-16 < 50 Shuangsi Dist. 2 December + + N-17 < 50 Shuangsi Dist. 1 December + + N-18 < 10 Xindian Dist. 1 October − + N-19 < 10 Xindian Dist. 1 November Un + N-20 < 10 Xizhi Dist. 1 December + + N-21 < 10 Taoyuan City Bade Dist. 1 September −− N-21 Bade Dist. 1 September − + N-22 < 10 Xinwu Dist. 1 September Un − N-23 < 50 Hsinchu County Guanxi Township 1 September + + C-24 < 10 Miaoli County Tongxiao Township 1 December − + C-25 < 50 Zhuolan Township 4 December + + C-26 < 10 Zhuolan Township 1 December Un + C-27 < 10 Taichung City Dadu Dist. 1 December − + C-28 < 10 Dadu Dist. 1 December + + C-29 < 10 South Dist. 1 November Un + C-30 < 10 Fengyuan Dist. 1 November −− C-31 < 10 Taiping Dist. 4 September −− C-32 < 10 Nantou County Puli Township 2 October − + C-33 < 10 Puli Township 3 December Un − S-34 < 10 Chiayi County Dalin Township 1 September + + S-34 Dalin Township 1 September Un + S-35 < 10 Shuesheliao 2 October Un − S-36 < 10 Zhuqi Township 1 September Un − S-37 < 10 Chiayi City Chiayi University 1 September Un − S-37 Chiayi University 1 October Un + S-38 < 10 Tainan City Anding Dist. 2 November −− S-39 < 10 Baihe Dist. 1 September Un + S-40 < 10 Houbi Dist. 1 September Un + S-41 < 10 Rende Dist. 1 September + + S-42 < 10 Shanhua Dist. 1 September + + S-43 < 10 Xinhua Dist. 1 October −− S-44 < 50 Yujin Dist. 2 October Un + S-45 < 10 Kaohsiung City Gangshan Dist. 1 October −− S-45 Gangshan Dist. 1 October − + S-46 < 10 Liugui Dist. 1 October Un − S-47 < 10 Qishan Dist. 1 October −− S-48 < 10 Pingtung County Wanluan Township 1 September −−

a Area symbols: C, Central; E, eastern; N, Northern; S, Southern. b Larval conditions were checked; “Un”: Unknown; “+”: Larvae with AcSBV symptoms; “−”: No obvious symptom. c AcSBV detection was performed by RT-PCR; “+”: sample with AcSBV infection; “−”: free from AcSBV infection. undergoing the outbreak. In this study, we have investigated A. cerana Materials and methods SBV (AcSBV) prevalence on both spatial and temporal aspects in the apiaries during the surveyed four months. These data would provide the Sample collections current situation of this disease in Taiwan. A total of 55 apiaries from 15 administrative regions in Taiwan were investigated from September to December 2016, which included 48 apiaries of Apis cerana and 7 apiaries of A. mellifera (Tables 1 and 2). Among them, there were 30 apiaries of A. cerana and 6 apiaries of A. mellifera that were available for further inspection. The combs in the

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