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Lu Z.C.,Chinese Academy of Agricultural Sciences | Sun H.B.,Chinese Academy of Agricultural Sciences | Wan F.H.,Chinese Academy of Agricultural Sciences | Wan F.H.,Center for Management of Invasive Alien Species | And 3 more authors.
Neotropical Entomology | Year: 2013

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle East-Asia Minor 1 (MEAM1) is invasive and adaptive to varied environments throughout the world. The adaptability is closely related to genomic variation such as single nucleotide polymorphisms (SNPs) and insertions/deletions (indels). In order to elucidate the feature of SNPs and indels in MEAM1, and reveal the association between SNPs/indels and adaptive capacity to various environments, a computational approach with QualitySNP was used to identify reliable SNPs and indels on the basis of 9110-expressed sequence tags of MEAM1 present in the NCBI database. There were 575 SNPs detected with a density of 10.1 SNPs/kb and 6.4 SNPs/contig. Also, 237 transitions (39.3%) and 366 transversions (60.7%) were obtained, where the ratio of transitions to transversions was 0.65:1. In addition, 581 indels with a density of 14.1 indels/kb and 9.2 indels/contig were detected. Collectively, it showed that invasive MEAM1 has high SNPs density, and higher SNPs percentage than non-invasive B. tabaci species. A high SNPs density/percentage in MEAM1 yielded a high genomic variation that might have allowed it to adapt to varied environments, which provides some support to understand the invasive nature of MEAM1 at the genomic level. High levels of genomic variation are implicated in the level of adaptive capacity and invasive species are thought to exhibit higher levels of adaptive capacity than non-invasive species. © 2013 Sociedade Entomológica do Brasil.


Lu Z.-C.,Chinese Academy of Agricultural Sciences | Li Q.,Chinese Academy of Agricultural Sciences | Liu W.-X.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Center for Management of Invasive Alien Species
PLoS ONE | Year: 2014

Temperature is an important factor in affecting population dynamics and diffusion distribution of organisms. Alien species can successfully invade and colonize to various temperature environments, and one of important reasons is that alien species have a strong resistance to stress temperature. Recently, researchers have focused on the mechanisms of temperature sensing to determine the sensing and regulation mechanisms of temperature adaptation. The transient receptor potential (TRP) is one of the key components of an organism's temperature perception system. TRP plays important roles in perceiving temperature, such as avoiding high temperature, low temperature and choosing the optimum temperature. To assess high temperature sensation and the heat resistance role of the TRP gene, we used 3′ and 5′ rapid-amplification of cDNA ends to isolate the full-length cDNA sequence of the TRP gene from Bemisia tabaci (Gennadius) MEAM1 (Middle East Asia Minor 1), examined the mRNA expression profile under various temperature conditions, and identified the heat tolerance function. This is the first study to characterize the TRP gene of invasive B. tabaci MEAM1 (MEAM1 BtTRP). The full-length cDNA of MEAM1 BtTRP was 3871 bp, and the open reading frames of BtTRP was 3501 bp, encoding 1166 amino acids. Additionally, the BtTRP mRNA expression level was significantly increased at 35°C. Furthermore, compared with control treatments, the survival rate of B. tabaci MEAM1 adults was significantly decreased under high temperature stress conditions after feeding with dsRNA BtTRP. Collectively, these results showed that MEAM1 BtTRP is a key element in sensing high temperature and plays an essential role in B. tabaci MEAM1 heat tolerance ability. Our data improved our understanding of the mechanism of temperature sensation in B. tabaci MEAM1 at the molecular level and could contribute to the understanding of the thermal biology of B. tabaci MEAM1 within the context of global climate change. © 2014 Lu et al.


Zhang G.F.,Chinese Academy of Agricultural Sciences | Zhang G.F.,Center for Management of Invasive Alien Species | Meng X.Q.,Chinese Academy of Agricultural Sciences | Min L.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Journal of Applied Entomology | Year: 2012

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is an invasive species and currently occurs in only a few areas in China. An easy, accurate and developmental-stage independent method to identify F. occidentalis would be a valuable tool to facilitate pest management decision making and, more importantly, to provide an early warning so actions can be taken to prevent its introduction into non-infested areas. Morphological identification of thrips adults and, to a lesser extent, of second-stage larvae is the main method currently available to identify F. occidentalis. Molecular identification, however, can be easily carried out by a non-thrips-specialist with a little training. In this study, DNA sequence data [within the mitochondrial cytochrome oxidase I gene (COI)] and polymerase chain reaction (PCR) were utilized to develop a molecular diagnostic marker for F. occidentalis. A primer set and PCR cycling parameters were designed for the amplification of a single marker fragment (340bp) of F. occidentalis COI mtDNA. Specificity tests performed on 28 thrips species, efficacy tests performed on five immature developmental stages as well as on male and female adults and tests on primer sensitivity all demonstrated the diagnostic utility of this marker. Furthermore, the primer set was tested on seventeen F. occidentalis populations from different countries and invaded areas in China and proved to be applicable for all geographic populations. It was used successfully to clarify the distribution of F. occidentalis in the Beijing metro area. These results suggested that this diagnostic PCR assay provides a quick, simple and reliable molecular technique for the identification of F. occidentalis. © 2011 Blackwell Verlag, GmbH.


Lu Z.-C.,Chinese Academy of Agricultural Sciences | Wang Y.-M.,Chinese Academy of Agricultural Sciences | Zhu S.-G.,Chinese Academy of Agricultural Sciences | Yu H.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Journal of Insect Science | Year: 2014

The invasive Mediterranean Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has emerged as one of the most common agricultural pests in the world. In the present study, we examined the cross-tolerance, fitness costs, and benefits of thermal tolerance and the variation in the responses of life history traits after heat-shock selection. The results showed that survival and longevity of Mediterranean B. tabaci were decreased significantly after direct or cross temperature stress and that the number of eggs per female was not reduced significantly. Furthermore, heat-shock selection dramatically increased the survival of Mediterranean B. tabaci within two generations, and it did not significantly affect the egg number per female within five generations. These results indicated that there was a trade-off between survival, longevity, and reproduction in Mediterranean B. tabaci after temperature stress. The improvement in reproduction was costly in terms of decreased survival and longevity, and there was a fitness consequence to temperature stress. In addition, heat tolerance in Mediterranean B. tabaci increased substantially after selection by heat shock, indicating a considerable variation for survival tolerance in this species. This information could help us better understand the thermal biology of Mediterranean B. tabaci within the context of climate change. © Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.


Lu Z.-C.,Chinese Academy of Agricultural Sciences | Gao Q.-L.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Center for Management of Invasive Alien Species | And 4 more authors.
Journal of Insect Science | Year: 2014

With increasing global climate change, analyses of stress-inducing conditions have important significance in ecological adaptation and the biological distribution of species. To reveal the difference in temperature-adaptive strategy between Turpan and Beijing populations of Bemisia tabaci (Gennadius) Middle East Asia Minor 1 (MEAM1) under high-temperature stress conditions, we compared thermal tolerance and life history traits between Beijing and Turpan populations of MEAM1 after exposure to different heat shock treatments for different times. The experimental design reflected the nature of heat stress conditions suffered by MEAM1. The results showed that eggs, red-eyed pupae, and adults of the Turpan population were more heat tolerant than those of the Beijing population under the same stress conditions. Additionally, it was found that longevity and F1 adult survival rate were significantly higher in the Turpan population than in the Beijing population after heat shock stress, but egg number and F1 female ratio were not significantly different between Turpan population and Beijing population. Overall, it was suggested that heat tolerance and longevity traits were the most relevant for climate characteristics and not reproductive traits, and improved heat tolerance and prolonged longevity were important adaptive strategies that helped MEAM1 to survive in harsh high-temperature conditions such as Turpan arid desert climate. The present results provided further insight into the modes of heat tolerance and the ways in which survival and longevity traits respond to environmental selection pressures. © The Author 2014.


Zhang G.-F.,Chinese Academy of Agricultural Sciences | Zhang G.-F.,Center for Management of Invasive Alien Species | Wu X.,Chinese Academy of Agricultural Sciences | Zhou Z.-X.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Entomologia Experimentalis et Applicata | Year: 2014

Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae) and Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), two important invasive species, are serious agricultural pests. In this study, a one-step, single tube, duplex polymerase chain reaction (PCR) procedure was developed to allow rapid, specific, and sensitive identification of B. tabaci MEAM1 and F. occidentalis in predator guts. The system and conditions used for the duplex PCR were optimized. The species specificity of the duplex PCR determined by comparison against non-targets that might interact with B. tabaci MEAM1 and F. occidentalis showed that oligonucleotide primers amplified nuclear gene target sequences present only in B. tabaci MEAM1 or F. occidentalis. The limits of detection were 9.53 ng μl-1 for B. tabaci MEAM1 and 8.94 ng μl-1 for F. occidentalis. Within a field cage study, in which predators Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) and Orius sauteri (Poppius) (Hemiptera: Anthocoridae) were allowed to feed on B. tabaci MEAM1 and F. occidentalis for 10 h, the B. tabaci MEAM1 DNA was detectable in 100% of H. axyridis and O. sauteri, and F. occidentalis DNA was detectable in 80% of H. axyridis and 90% of O. sauteri; this implicated that B. tabaci MEAM1 and F. occidentalis remains could be detected in native predator guts simultaneously. The accuracy and reliability of the assay suggested strongly that the duplex PCR optimized for B. tabaci MEAM1 and F. occidentalis is sensitive and specific for both invasive insects and is therefore useful in early diagnosis and monitoring of B. tabaci MEAM1 and F. occidentalis infections, and can be used to identify domestic predator species and food web relationships. © 2013 The Netherlands Entomological Society.


Ma F.-Z.,Chinese Academy of Agricultural Sciences | Lu Z.-C.,Chinese Academy of Agricultural Sciences | Wang R.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Center for Management of Invasive Alien Species
PLoS ONE | Year: 2014

With advancing global climate change, the analysis of thermal tolerance and evolutionary potential is important in explaining the ecological adaptation and changes in the distribution of invasive species. To reveal the variation of heat resistance and evolutionary potential in the invasive Mediterranean cryptic species of Bemisia tabaci, we selected two Chinese populations - one from Harbin, N China, and one from Turpan, S China - that experience substantial heat and cold stress and conducted knockdown tests under static high- and low-temperature conditions. ANOVAs indicated significant effects of populations and sex on heat knockdown time and chill coma recovery time. The narrow-sense heritability (h2) estimates of heat tolerance based on a parental half-sibling breeding design ranged from 0.47±0.03 to 0.51±0.06, and the estimates of cold tolerance varied from 0.33±0.07 to 0.36±0.06. Additive genetic variances were significantly different from zero for both heat and cold tolerance. These results suggest that invasive B. tabaci Mediterranean cryptic species possesses a strong ability to respond to thermal selection and develops rapid resistance to climate change. © 2014 Ma et al.


Lu Z.-C.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Chinese Academy of Agricultural Sciences | Wan F.-H.,Center for Management of Invasive Alien Species
Journal of Experimental Biology | Year: 2011

The whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) biotype B, is one of the most destructive invasive pests of field and glasshouse crops, and has a high tolerance to heat. Our previous work found that whitefly females are more heat tolerant than males. In the present study, real-time PCR and double-stranded RNA (dsRNA) methods were used to explore the role of heat shock protein (Hsp) genes in whitefly of both sexes; this provided further evidence of the mechanism underlying the differential heat tolerance abilities of females and males. The results showed that both hsp23 and hsp70 mRNA expression levels were higher in females than in males from 37.5 to 42°C, while at the extreme temperature of 44°C the hsp70 mRNA level was higher in males than in females. There was no significant difference in hsp90 mRNA expression between females and males under heat shock conditions. Furthermore, the survival rate of females fed hsp23 or hsp70 dsRNA significantly decreased following heat shock at 44°C for 1 h, but male survival rate was not significantly affected. Additionally, the survival rate of both females and males showed no significant change after they were fed with hsp90 dsRNA. Collectively, the present study shows that the optimum mRNA expression of Hsp genes in females promotes a higher survival rate under heat shock conditions; hsp23 and hsp70 play a key role for heat tolerance in females but not in males, and hsp90 shows no significant role in heat tolerance in either females or males. Further, our study indicates that feeding with dsRNA is an effective method by which to study gene function, and the simplicity of this approach opens the way for further research on gene function in different sexes and diverse groups of species. © 2011. Published by The Company of Biologists Ltd.


Lu Z.-C.,Chinese Academy of Agricultural Sciences | Wang L.-H.,Chinese Academy of Agricultural Sciences | Wang L.-H.,Henan Institute of Science and Technology | Dai R.-L.,Chinese Academy of Agricultural Sciences | And 5 more authors.
Florida Entomologist | Year: 2014

Quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) is widely used for gene expression analysis in living organisms, and stably expressed endogenous reference genes are needed to obtain accurate results. Some commonly used reference genes varied among different experimental treatments. To obtain suitable reference gene for specific experimental conditions, the stability of 10 reference genes of Bactrocera (Tetradacus) minax (Enderlein) were evaluated in various development stages, and under temperatureand -irradiation-stress conditions by semi-quantitative PCR. The present results indicated that the most stable candidate reference gene was RPL32 in eggs, 3rd instars, 1-, 90- and 160-day-pupae and newly emerged female and male adults (< 24 h), and under different stress conditions, i.e., 35 C temperature stress for 0 h, 1 h, 3 h and 5 h, and 4 C temperature stress for 0 h, 12 h, 36 h, 48 h and 60 h. GAPDH, G6PDH and RPL32 were ideal candidate endogenous genes under 35 C temperature stress for 0 h, 1 h, 3 h and 5 h, and under 4 C temperature stress for 0 h, 12 h, 36 h, 48 h and 60 h, and under a irradiation stress of 90 Gy. These results provide basic information for future studies of gene expression in B. minax, and should serve as a resource to screen reference genes for gene expression studies in other insect species.


Zhang X.,Chinese Academy of Agricultural Sciences | Yang N.,Chinese Academy of Agricultural Sciences | Yang N.,Center for Management of Invasive Alien Species | Wan F.,Chinese Academy of Agricultural Sciences | Wan F.,Center for Management of Invasive Alien Species
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014

The whitefly, Bemisia tabaci (Gennadius) is a key agricultural pest in many regions of the world, and has been a destructive pest in China during the past two decades. B. tabaci is extremely polyphagous, feeding on hundreds of host plants, causing direct and indirect damage. Direct feeding by adults and nymphs induces physiological disorders in host plants, resulting in smaller production, shedding of leaves, and death in immature plants. The honeydew produced by the nymphs often causes stunting by promoting the growth of black sooty mold on leaves and reducing photosynthesis. However, the main damage is indirect: B. tabaci can transmit more than 100 plant viruses that damage many commercial plants. B.tabaci has distinct host plant preferences, and knowing these can serve as a basis for integrated pest management programs, especially because resistance to insecticides by B. tabaci is on the increase. Here we present the results of an exhaustive survey of host plants in Northern China. A systematic field survey was conducted on 81 plant species to investigate their suitability as host plants for B. tabaci at Langfang, Hebei Province. There were three plots for each plant, with a size of 16 m2(4 m×4 m) for each plot, 243 plots were randomly arranged in total. Infection rate was characterised by the number of individuals per 100 cm2 leaf and number of individuals per whole leaves. A total of 37 species of the surveyed plants, including Zea mays L., Sorghum bicolor (L.) Moench and Setaria italica (L.) Beauv. were not damaged by B.tabaci. Plant species belonging to the families Rosaceae, Nyctaginaceae, Caryophyllaceae, Linaceae, Cleomaceae, Euphorbiaceae, Rutaceae, Asclepiadaceae (surveyed one species in these families), Polygonaceae (surveyed two species), Cruciferae (surveyed four species), Poaceae (surveyed five species) were not damaged by B. tabaci. Forty-four of the investigated plant species were suitable hosts for B. tabaci. The plants from Lamiaceae, Leguminosae, Asteraceae, Convolvulaceae and Malvaceae supported the higher whitefly densities than the other plant families in our survey results. Most of the surveyed species in the Lamiaceae family were damaged, and on more than 60% of these plants, the infection rate reached grade 4 (>50 individuals per 100 cm2 leaf). Whitefly densities on these host plants varied widely. The whitefly occurred mostly on Mentha arvensis L., Schizonepeta tenuifolia Briq, Glycyrrhiza uralensis Fisch, Mentha canadensis L., Leonurus japonicus Houtt, Crotalaria pallida Ait., Chrysanthemum paludosum Poir, Achyranthes bidentata Blume, Oenothera erythrosepala Borb., Echium vulgare L., Medicago sativa L. and Ocimum basilicum L.. The infection rate on these plants was grade 4 (>50 individuals per 100 cm2 leaf). Althaea rosea (L.) Cavan, Helianthus annuus L. and Nicotiana tabacum L. had somewhat lower densities per 100 cm2 leaf, but themselves being much larger than the former host plant species, whole plants supported large whitefly populations. H. annuus, Z. may and S. bicolor are widely planted in cotton production areas in northern China, and the economic losses caused by whitefly infection on these plants was relatively low. H. annuus can potentially be used as a trap crop, while Z. may and S. bicolor can be used as barrier crops to manage whiteflies in cotton fields. © 2014, Science Press. All rights reserved.

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