scholarly journals Competitive Displacement between Bemisia tabaci MEAM1 and MED and Evidence for Multiple Invasions of MED

Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Xiao-Tian Tang ◽  
Li Cai ◽  
Yuan Shen ◽  
Li-Li Xu ◽  
Yu-Zhou Du
Keyword(s):  
Bemisia Tabaci ◽  
Mitochondrial Gene ◽  
Economic Loss ◽  
Plant Viruses ◽  
Competitive Displacement ◽  
Severe Damage ◽  
Large Numbers ◽  
Multiple Introduction ◽  
Invasive Whitefly ◽  
Multiple Invasions

Despite the severe ecological damage and economic loss caused by invasive species, the factors contributing to successful invasion or displacement remain elusive. The whitefly, Bemisia tabaci (Gennadius), is an important invasive agricultural pest worldwide, causing severe damage to numerous crops by feeding or transmitting plant viruses. In this study, we monitored the dynamics of two invasive whitefly cryptic species, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), in Jiangsu, China, from 2005–2016. We found that B. tabaci MED quickly established and asserted dominance over MEAM1, resulting in their population displacement in Jiangsu in only three years (from 2005 to 2008). We further investigated the possible mechanisms underlying the successful invasion and competitive displacement from a genetic perspective. Based on sequencing of mitochondrial gene sequences from large numbers of whitefly samples, multiple invasion events of MED were validated by our genetic analyses. MED invaded Jiangsu starting from multiple introduction sites with secondary and/or subsequent invasive events. This may favor their invasion and displacement of MEAM1. This study advances our understanding of the mechanisms that enabled the successful invasion of MED.

scholarly journals Factors Determining Transmission of Persistent Viruses by Bemisia tabaci and Emergence of New Virus–Vector Relationships

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1808
Author(s):  
Saptarshi Ghosh ◽  
Murad Ghanim
Keyword(s):  
Bemisia Tabaci ◽  
Plant Viruses ◽  
Tomato Yellow Leaf ◽  
Tissue Tropism ◽  
Insect Vectors ◽  
Virus Species ◽  
Yellow Leaf ◽  
Virus Diseases ◽  
Persistent Viruses ◽  
Leaf Curl Virus

Many plant viruses depend on insect vectors for their transmission and dissemination. The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important virus vectors, transmitting more than four hundred virus species, the majority belonging to begomoviruses (Geminiviridae), with their ssDNA genomes. Begomoviruses are transmitted by B. tabaci in a persistent, circulative manner, during which the virus breaches barriers in the digestive, hemolymph, and salivary systems, and interacts with insect proteins along the transmission pathway. These interactions and the tissue tropism in the vector body determine the efficiency and specificity of the transmission. This review describes the mechanisms involved in circulative begomovirus transmission by B. tabaci, focusing on the most studied virus in this regard, namely the tomato yellow leaf curl virus (TYLCV) and its closely related isolates. Additionally, the review aims at drawing attention to the recent knowhow of unorthodox virus—B. tabaci interactions. The recent knowledge of whitefly-mediated transmission of two recombinant poleroviruses (Luteoviridae), a virus group with an ssRNA genome and known to be strictly transmitted with aphids, is discussed with its broader context in the emergence of new whitefly-driven virus diseases.

scholarly journals RNAi-Mediated Management of Whitefly Bemisia tabaci by Oral Delivery of Double-stranded RNAs

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 11
Author(s):  
Jain ◽  
Robinson ◽  
Mitter
Keyword(s):  
Rna Interference ◽  
Gene Silencing ◽  
Bemisia Tabaci ◽  
Oral Delivery ◽  
Target Genes ◽  
Insect Pests ◽  
Control Strategies ◽  
Plant Viruses ◽  
Potential Game ◽  
Viable Approach

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a significant global pest of economically important vegetable, fibre, and ornamental crops. Whiteflies directly damage the plants by piercing and sucking essential nutrients, indirectly through honeydew secretion and by transmitting more than 200 plant viruses that cause millions of dollars in produce losses per year. Whitefly management is mostly reliant on the heavy use of chemical insecticides. However, this ultimately leads to increasing resistance development, detrimental effects on beneficial insects and biomagnification of ecologically harmful chemicals in the environment. Responding to consumer demands for more selective, less toxic, non-GM insect control strategies, RNA interference (RNAi) has emerged as a potential game-changing solution. The RNA interference (RNAi) is a homology-dependent mechanism of gene silencing that represents a feasible and sustainable technology for the management of insect pests. In the present study, twenty-two whitefly genes were selected based on their essential function in the insect and tested in artificial diet bioassays for mortality and gene silencing efficacy. The nine most effective dsRNA constructs showed moderate-to-high whitefly mortality as compared to negative controls six days post-feeding. qPCR analysis further demonstrated significant knockdown of target gene mRNA expression. Additionally, uptake and spread of fluorescently labelled dsRNA was evident beyond the midgut of the whitefly supporting the systemic spreading of RNAi effectors. Taken together, the oral delivery of dsRNA shows effective RNAi mediated gene silencing of target genes and offers a viable approach for the development of dsRNA biopesticides against hemipteran pest.

Risk Based Inspection for Prioritizing Repair and Inspections of Large Numbers of Platforms in Gulf of Suez

2006 ◽  
Author(s):  
Mohamed A. El-Reedy
Keyword(s):  
Main Part ◽  
Pushover Analysis ◽  
Gulf Of Suez ◽  
Severe Damage ◽  
Rule Based ◽  
Structure Condition ◽  
Large Numbers ◽  
Key Characteristics ◽  
Integrity Management ◽  
Main Factor

GUPCO has more than hundred platforms located in Gulf of Suez that require topsides and underwater inspections on a regular basis as a part of integrity management system. Because of the high cost of underwater inspections and repair, GUPCO has developed a risk-based process to more effectively implement inspection resources. The process is based upon the critical key characteristics of each platform (year designed, number of legs, framing configuration, manning level, etc.) as well as results from previous inspections (date of last inspection, amount of inspection, flooded members, cut member, excessive marine growth, anode status, etc.). Using this information, the overall “risk” of the platform is determined using a rule-based scoring estimation of the likelihood and consequence of failure. In parallel, the severe damage platform structure is assessment by performing pushover analysis. The platforms are then ranked from highest to lowest risk, with the highest risk platforms receiving priority for repair and inspections. By calculating the likelihood of failure which is the main part of the assessment it is found that the age is the main factor affecting the structure condition. So from this paper one can calculate approximate value for failure likelihood occurring to the structure by knowing its age.

scholarly journals Transmission of the Bean-Associated Cytorhabdovirus by the Whitefly Bemisia tabaci MEAM1

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1028
Author(s):  
Bruna Pinheiro-Lima ◽  
Rita C. Pereira-Carvalho ◽  
Dione M. T. Alves-Freitas ◽  
Elliot W. Kitajima ◽  
Andreza H. Vidal ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Control Strategies ◽  
Genomic Data ◽  
Plant Viruses ◽  
Asia Minor ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Lower Efficiency ◽  
Viral Particles ◽  
Pathogenicity Tests

The knowledge of genomic data of new plant viruses is increasing exponentially; however, some aspects of their biology, such as vectors and host range, remain mostly unknown. This information is crucial for the understanding of virus–plant interactions, control strategies, and mechanisms to prevent outbreaks. Typically, rhabdoviruses infect monocot and dicot plants and are vectored in nature by hemipteran sap-sucking insects, including aphids, leafhoppers, and planthoppers. However, several strains of a potentially whitefly-transmitted virus, papaya cytorhabdovirus, were recently described: (i) bean-associated cytorhabdovirus (BaCV) in Brazil, (ii) papaya virus E (PpVE) in Ecuador, and (iii) citrus-associated rhabdovirus (CiaRV) in China. Here, we examine the potential of the Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) to transmit BaCV, its morphological and cytopathological characteristics, and assess the incidence of BaCV across bean producing areas in Brazil. Our results show that BaCV is efficiently transmitted, in experimental conditions, by B. tabaci MEAM1 to bean cultivars, and with lower efficiency to cowpea and soybean. Moreover, we detected BaCV RNA in viruliferous whiteflies but we were unable to visualize viral particles or viroplasm in the whitefly tissues. BaCV could not be singly isolated for pathogenicity tests, identification of the induced symptoms, and the transmission assay. BaCV was detected in five out of the seven states in Brazil included in our study, suggesting that it is widely distributed throughout bean producing areas in the country. This is the first report of a whitefly-transmitted rhabdovirus.

scholarly journals Effect of okra plant resistance on transmission rate of okra enation leaf curl virus by its vector whitefly, Bemisia tabaci

2021 ◽  
Vol 13 (SI) ◽  
pp. 63-68
Author(s):  
E. Pasupathi ◽  
M. Murugan ◽  
C. Chinniah ◽  
J. Ramalingam ◽  
G. Karthikeyan ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Plant Resistance ◽  
Transmission Rate ◽  
Resistance Mechanisms ◽  
Plant Viruses ◽  
Symptom Expression ◽  
Virus Symptom ◽  
Leaf Curl Virus ◽  
Effect Of Age ◽  
Leaf Curl

The present study aimed to investigate the effect of age of the okra plants that showed varying whitefly resistance responses on the transmission rate of okra enation leaf curl virus (OELCV) by its vector whitefly Bemisia tabaci. The OELCV infected whitefly adults were collected from whitefly colonies and were challenged on the test okra accessions (Upl mona 2, Co 1, Arka anamika and AE 64) of differential ages which were individually caged (7, 10 and 15 d after germination) with glass chimney and the number of such whiteflies used were at the rate of 2, 4, 6, 8, 10, 12, 14 and 20 adults per plant. Observations were made on the virus symptom expression 30 d after challenge. The efficiency of transmission was determined. The efficiency of transmission of OELCV was the highest (maximum T and P*, 0.80, 1.00 and 0.08, 0.10) when 7 d old seedlings were inoculated (Arka anamika and AE 64 respectively) and transmission had decreased as the age of seedlings increased. The estimated transmission rate for single whitefly (P*) increased with an increase in the number of whiteflies used per plant. Okra plant resistance to B. tabaci significantly changed the transmission rates of OELCV on okra. Understanding the resistance mechanisms of the okra accessions and interactions between plant viruses and their insect host can pave the way for novel approaches to protect plants from virus infection.

scholarly journals Kemampuan reproduksi dan riwayat hidup kutukebul Bemisia tabaci (Gennadius) dengan dan tanpa kopulasi pada tanaman cabai merah dan tomat

2020 ◽  
Vol 17 (3) ◽  
pp. 156
Author(s):  
Purnama Hidayat ◽  
Rika Ludji ◽  
Nina Maryana
Keyword(s):  
Bemisia Tabaci ◽  
Female Offspring ◽  
Plant Viruses ◽  
Instar Nymph ◽  
Chili Pepper ◽  
Female Adult ◽  
Tomato Plants ◽  
Male And Female ◽  
Plant Parts ◽  
Egg Incubation

<span lang="EN-US">The sweet potato whitefly, <em>Bemisia tabaci</em> (Gennadius) is a cosmopolitan pest on various types of agricultural crops. The whitefly is able to cause damage to plants by directly consuming plant parts using stylet and as a vector of plant viruses. Red chili (<em>Capsicum annuum</em>) and tomato (<em>Solanum lycopersicum</em>) plants are important horticultural plants that are often infested by <em>B. tabaci</em>. Whiteflies are known to reproduce with copulation that produce male and female offspring and without copulation that produce male offspring. The purpose of this study was to determine the reproduction ability of <em>B. tabaci</em> with and without copulation in red chili pepper and tomato. Adult of <em>B. tabaci</em> was taken from a greenhouse in Cikabayan, IPB Dramaga. One female who just emerged from the pupa or final instar nymph was invested in red chilli and tomato plants in polybags to determine the <em>B. tabaci</em> offspring produced without copulation. The same method was also done for whitefly with copulation, but using a pair of adult whitefly (male and female). Each treatment was repeated 5 times. Observations were made every day on the number of eggs produced by one female adult per day, the egg incubation period, the length of the nymph period for each instar, pupa, and adult. The results of this study showed that the fertility of <em>B. tabaci</em> which reproduces with and without copulation in tomato plants was higher than in chili pepper plants, but there was no difference in life cycle and sex ratio.</span>

Reproductive incompatibility between the B and Q biotypes of the whitefly Bemisia tabaci in China: genetic and behavioural evidence

2010 ◽  
Vol 101 (2) ◽  
pp. 211-220 ◽  
Author(s):  
D.B. Sun ◽  
J. Xu ◽  
J.B. Luan ◽  
S.S. Liu
Keyword(s):  
Bemisia Tabaci ◽  
Phylogenetic Analyses ◽  
Severe Damage ◽  
Crossing Experiments ◽  
Video Observations ◽  
Reproductive Incompatibility ◽  
F1 Progeny ◽  
Opposite Sex ◽  
Reproductive Compatibility ◽  
Behavioural Evidence

AbstractThe B and Q ‘biotypes’ of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) have been invading many parts of the world and causing severe damage to a range of crops. Recent phylogenetic analyses indicate that B and Q are cryptic species within the B. tabaci species complex. Although various attempts have been made to examine the reproductive compatibility between B and Q, few studies have tested the fertility of the F1 females and so the extent of possible gene flow remains unclear. In this study, we conducted a series of crossing experiments and behavioural observations to examine in detail the reproductive compatibility between the B and Q biotypes collected from Zhejiang, China, a region recently invaded by these whiteflies. Crossing experiments between the two biotypes using either single-pairs or small groups demonstrated that proportions of females in the F1 progeny were only 0–2% in the inter-biotype crosses compared to 58–68% in the intra-biotype treatments. Furthermore, all inter-biotype F1 females were sterile. Continuous video observations showed that B and Q adults very rarely copulated, and copulation occurred only when adults of opposite sex from different biotypes were enclosed in dense cohorts for a relatively long period of time. These data show that the B and Q biotypes examined in this study are completely isolated in reproduction. The isolation was due to mainly a copulation barrier, but post-copulation barriers were also involved.

scholarly journals Improved efficacy of neonicotinoid in tablet formulation on the control of tomato chlorosis virus by controlling the vector Bemisia tabaci

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Lei Li ◽  
Zhihong Hu ◽  
Tan Dai ◽  
Panqing Liu ◽  
Chen Chen ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Environmental Contamination ◽  
Foliar Spray ◽  
Plant Viruses ◽  
Tablet Formulation ◽  
Soil Treatment ◽  
In Vitro Test ◽  
Sustained Release Tablets ◽  
Tomato Chlorosis Virus

AbstractNeonicotinoid insecticides are used for preventing insects from transmitting plant viruses. This group of chemicals are easily taken up by plants and translocated to different tissues and are applicable for soil treatment in sustained-release tablets, which greatly reduces environmental contamination compared to foliar spray. The goal of this study was to examine the efficacy of thiamethoxam, acetamiprid and nitenpyram in tablet formulation against whitefly, Bemisia tabaci, the vector of tomato chlorosis virus (ToCV) under laboratory and greenhouse conditions. Effective 50% lethal concentration (LC50) of thiamethoxam, acetamiprid, and nitenpyram on B. tabaci were 2.18, 0.46 and 0.18 μg/g plant tissue, respectively. In vitro test showed that tablets of 10 mg nitenpyram applied in seedbed with thiamethoxam transplanting treatment showed 80.9% control of B. tabaci on tomato and 75.5% of ToCV after 32 days of transplanting. Therefore, neonicotinoid tablets were an effective strategy of soil treatment in controlling viruliferous insects and ToCV with reduced environmental contamination.

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