Effects of Flower Thinning Formulation on Activities of Digestive Enzymes and Acetylcholine Esterase in Honey bee Apis mellifera

Hemayet Jahan, S.M.,Shim, Jae-Kyoung,Son, Tae-Gwon,Jo, Jaedoo,Choi, Cheul,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol. No.

The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

Molecular Variation of Endosymbiotic Bacteria Wolbachia in Bemisia tabaci and Related Whiteflies

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2012 慶北大農學誌 Vol.30 No.2

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.

Upregulation of Endosymbiont Densities in Bemisia tabaci by Acquisition of Tomato Yellow Leaf Curl Virus

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2012 慶北大農學誌 Vol.30 No.2

Sweetpotato whitefly, Bemisia tabaci, is a vector of more than 100 plant-diseased viruses, as well as a serious pest of various horticultural plants. This species harbors a primary endosymbiont Portiera along with several secondary endosymbionts such as Cardinium and Hamiltonella. We investigated whether or not TYLCV acquisition alters the densities of endosymbionts in the body of B. tabaci using quantitative real-time PCR. Our results showed that the densities of both Cardinium and Hamiltonella, but not Portiera, increased upon acquisition of TYLCV. In addition, expression of GroEL, a molecular chaperone produced by Hamiltonella, was significantly upregulated in TYLCV-infected whiteflies. Our results suggest that endosymbionts may play an important role in TYLCV transmission mechanism within the body of B. tabaci.

Molecular Variation of Endosymbiotic Bacteria Wolbachia in Bemisia tabaci and Related Whiteflies

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll 경북대학교 농업생명과학대학 2012 Current Research on Agriculture and Life Sciences Vol.30 No.2

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.

Upregulation of Endosymbiont Densities in Bemisia tabaci by Acquisition of Tomato Yellow Leaf Curl Virus

Jahan, S.M. Hemayet,Lee, Kyeong-Yeoll 경북대학교 농업생명과학대학 2012 Current Research on Agriculture and Life Sciences Vol.30 No.2

Sweetpotato whitefly, Bemisia tabaci, is a vector of more than 100 plant-diseased viruses, as well as a serious pest of various horticultural plants. This species harbors a primary endosymbiont Portiera along with several secondary endosymbionts such as Cardinium and Hamiltonella. We investigated whether or not TYLCV acquisition alters the densities of endosymbionts in the body of B. tabaci using quantitative real-time PCR. Our results showed that the densities of both Cardinium and Hamiltonella, but not Portiera, increased upon acquisition of TYLCV. In addition, expression of GroEL, a molecular chaperone produced by Hamiltonella, was significantly upregulated in TYLCV-infected whiteflies. Our results suggest that endosymbionts may play an important role in TYLCV transmission mechanism within the body of B. tabaci.

Effects of Flower Thinning Formulation on Activities of Digestive Enzymes and Acetylcholine Esterase in Honey bee Apis mellifera

Hemayet Jahan, S.M.,Shim, Jae-Kyoung,Son, Tae-Gwon,Jo, Jaedoo,Choi, Cheul,Lee, Kyeong-Yeoll 경북대학교 농업생명과학대학 2014 Current Research on Agriculture and Life Sciences Vol.32 No.2

The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

Upregulation of probing‐ and feeding‐related behavioural frequencies in <i>Bemisia tabaci</i> upon acquisition of <i>Tomato yellow leaf curl virus</i>

Jahan, SM Hemayet,Lee, Gwan‐,Seok,Lee, Sukchan,Lee, Kyeong‐,Yeoll John Wiley Sons, Ltd 2014 Pest Management Science Vol.70 No.10

<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>The behaviour of insect vectors can be altered by the acquisition of plant viruses. <I>Bemisia tabaci</I>, which is the vector of <I>Tomato yellow leaf curl virus</I> (TYLCV), causes damage to susceptible tomato cultivars. Here, the frequencies of several behavioural characteristics related to probing and feeding that are exhibited by non‐viruliferous (NV) and TYLCV‐viruliferous (V) adult <I>B. tabaci</I> were compared using a sandwich‐type parafilm cage.</P><P><B>RESULTS</B></P><P>The frequencies of behaviours such as wing flapping, leg movement, body shaking and body position change while settling and feeding on plant leaves were higher in V than in NV whiteflies. Evaluation of probing frequencies by measuring the number and size of holes punctured in parafilm by whiteflies revealed that most holes had a diameter of 7.5–26.7 µm, which is within the range of proboscis diameters of whiteflies. There were more small‐sized holes than medium‐ and large‐sized holes. Male whiteflies produced more small‐sized holes, but females more mid‐sized holes. V whiteflies showed increased hole numbers but decreased feeding duration relative to NV whiteflies.</P><P><B>CONCLUSION</B></P><P>Adult <I>B. tabaci</I> showed higher frequencies of probing and feeding behaviours when infected with TYLCV. These manipulations of feeding behaviours of insect vectors may result in increased transmission of plant virus. © 2014 Society of Chemical Industry</P>

The Relationship between Endosymbiont Densities of Bemisia tabaci and the Transmission of Tomato Yellow Leaf Curl Virus (TYLCV)

S. M. Hemayet Jahan,Hong-Soo Choi,Kwan-Suk Lee,Chang-Suk Kim,Sukchan Lee,Kyoeong-Yeoll Lee 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

The sweetpotato whitefly, Bemisia tabaci, acts as a vector of more than 100 plant viruses. B. tabaci is known to harbor a primary endosymbiont (Portiera) and 6 secondary endosymbionts (Arsenophonus, Cardinium, Fritschea, Hamiltonella, Rickettsia and Wolbachia). These endosymbionts play important roles in the acquisition and transmission of plant viruses. Using PCR analysis, we identified endosymbiotic bacteria in various B. tabaci populations collected from different places of Korea. Distribution of endosymbionts was different according to the biotype of B. tabaci. Subsequently, their relative densities of endosymbionts were compared between TYLCV-viruliferous and non-viruliferous populations of the Q biotype using quantitative realtime PCR. We found that the densities of Portiera, Cardinium and Hamiltonella are higher in viruliferous than non-viruliferous whiteflies. Our results suggest the role of endosymbiont for the TYLCV transmission of whiteflies.

Acquisition of Tomato yellow leaf curl virus enhances attraction of Bemisia tabaci to green light emitting diodes

S.M. Hemayet Jahan,이관석,이석찬,이경열 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.1

The light sensitivity of insects varies in response to differentwavelengths of light. The change of light responses ofvector insects plays an important role in the method of transmission and propagation of plant viruses. Here, weinvestigated whether the light attraction behaviors of whiteflies are altered by virus acquisition. Firstly, the lightattraction rates of whiteflies were determined using LED light bulbs exhibiting different wavelengths in thevisible and UV spectra. Whiteflies, Bemisia tabaci and Trialeurodes vaporariorum, were mostly attracted togreen LEDs (526 nm). The attraction rate to green LED light was higher in B. tabaci than in T. vaporariorum,whereas it did not significantly differ between the B- and Q-biotypes of B. tabaci. Secondly, we investigatedwhether or not the green light attraction behavior of B. tabaci is influenced by the acquisition of Tomato yellowleaf curl virus (TYLCV). The attraction rate to green LED lightwas 2.5–3 times higher in TYLCV-infectedwhitefliesthan in TYLCV-freewhiteflies. However, this difference disappearedwhen the distance from the light sourcewasgreater than 0.5 m. Our results show that B. tabaci favors green light and its attraction is highly enhanced by theacquisition of the plant virus, TYLCV.

Risk analysis of the plant pathogenic viruses screening from southern part of Bangladesh

S. M. Hemayet Jahan,Md. Asaduzzaman 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

Frequent surveys and monitoring were conducted in the Southern part of Bangladesh to detect and identify the plant pathogenic virus that infecting agriculturally important vegetables during 2017-2018. A total of 28 fields of the survey area were closely monitored. The findings indicated that 21.94% of the plants developed typical virus disease like symptomps in the field. However, 28.21% infected plants were found in Patuakhali followed by Satkhira (23.11%), Khulna (19.33%) and Barguna (17.12%). The symptoms were mosaic, vein clearing, chlorosis, curling and ringspot. Twenty samples from the collections were randomly chosen on the basis of symptoms and subjected to Enzyme-linked Immunosorbent Assay (ELISA) with the antiserum and symptomalogy were used for detection. Eight viruses namely Cucumber mosaic virus (CMV), Okra yellow vein clearing mosaic virus (OYVCMV), Mungbean yellow mosaic virus (MYMV), Tomato yellow leaf curl virus (TYLCV), Pepper mottle virus (PMV), Papaya ringspot virus (PRSV), Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) were detected on cucumber, okra, brinjal, mungbean, tomato, pepper, papaya, watermelon and pumpkin respectively.