Banana Aphid Pentalonia Nigronervosa Research Articles

Morphometrics and biological characteristics of Pentalonia nigronervosa, the vector of Banana bunchy top virus, living on various Araceous plants species

Banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is widely known as the main vector of Banana bunchy top virus (BBTV). It had been reported that banana aphid could live on alternative hosts belong to Family Araceae, and become important issue since Araceous plants are commonly found surrounding banana cultivations. Research had been conducted to study the morphometrics and biological characteristics of banana aphids living on various species of Araceous plants. The results showed that Araceous plant species could influence the morphometric and biological characteristic of banana aphids, indicated by the significant difference in some biological characteristics such as life cycle, life span, reproductive period, and fecundity. The average life span of banana aphids living on Araceous plants ranged from 22.80 to 47.90 days, it was shorter than the one that of lived on a banana plants. P. nigronervosa was able to develop a bigger colony when the aphid lived on Araceous plants, especially when they were transferred to Bogor taro where their fecundity reached 63 nymphs per female. Araceous plants also affected the morphometric of P. nigronervosa indicated by smaller size of the aphids, compared to those living on banana plant. The ability of banana aphid to live and reproduce in various Araceous plants would be beneficial to the development of control strategies of BBTV.

Pengaruh Spesies Tumbuhan Araceae terhadap Efisiensi Penularan Banana Bunchy Top Virus oleh Pentalonia nigronervosa

Araceous plants can serve as alternative host to banana aphid Pentalonia nigronervosa. Research has been conducted to study the effects of Araceous plant species on the efficiency of Banana Bunchy Top Virus (BBTV) transmission by P. nigronervosa as the main vector of the virus. The research was an experiment conducted in Experimental Garden, Department of Plant Protection, Faculty of Agriculture Sriwijaya University from November 2021 to April 2022. The experiment was conducted using 7 species of Araceous plant and one genotype of banana. The results of the research showed that, when serving as alternataive host of P. nigronervosa , all Araceous plants had no effect on the efficiency of BBTV transmission by the aphid. Viruliverous P. nigronervosa did not lose their virus particles in their body and still had ability to transmit the virus ehen they were transferred from Araceous plant to healthy banana.In cubation period ranged from 25-37,6 days after inoculation and the symptoms appeared mostly on young leaves.

Monitoring the distribution of banana bunchy top virus in South Africa: a country-wide survey.

Banana bunchy top disease is the most devastating viral disease of bananas worldwide and is caused by banana bunchy top virus (BBTV). The disease is spread by the banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) and through infected propagation material. In 2016, the virus was detected for the first time in an isolated area in the South Coast region of KwaZulu-Natal Province (KZN), South Africa. The aim of this study was to conduct surveys across all banana-producing regions in South Africa, viz. KwaZulu-Natal, Mpumalanga, and Limpopo provinces. Over 1700 plant and aphid samples were collected from commercial farms and rural households in the three provinces, and more-intense sampling was done in the affected KZN region. A BBTV-specific PCR targeting DNA-R (encoding the master replication initiation protein, M-Rep) was used to detect virus-infected samples, and amplicons of the expected size were sequenced. Comparative phylogenetic analysis showed that the South African BBTV isolates clustered within the Pacific Indian Oceans genomic group, which includes isolates from India and other regions in Africa, with a bootstrap value of 94%. To date, the virus has been identified only in the South Coast region of KwaZulu-Natal Province. Intense management strategies, including scouting, removal of infected plants, and control of aphids, have been implemented in areas where positive samples were identified to minimize the spread of the virus.

Response of banana germplasms to banana bunchy top virus

Banana bunchy top virus (BBTV) is one of the important viruses causing disease in bananas and its infection has the potential to cause yield loss. This study was conducted to evaluate the response of several commercial cultivars (Cavendish, Bebek, Goroho, Tanduk, and Barangan Merah) and wild accessions (Klutuk NTT, Halabanensis, SPn 001, LNT 001, and Microcarpa) of banana to BBTV infection. Transmission of BBTV was carried out through banana aphid Pentalonia nigronervosa, using 20 adult aphids per plant with an acquisition feeding period of 24 hours on BBTV-infected plants and an inoculation feeding period on healthy test plants for 48 hours. Observation on plant growth and disease intensity was conducted for 8 weeks after inoculation. At the end of the observation period, only 5 cultivars, i.e. Cavendish, Bebek, Goroho, Barangan Merah, and Halabanensis showed typical symptoms of BBTV with disease incidence reached 80%, 60%, 20%, 20%, and 20% respectively. Significant inhibition of plant height and leaves width occurred in Cavendish, Bebek, and Goroho i.e. 44.60%, 36.31%; 12.62%, 41.08%; and 25%, 10.13%, respectively. This paper discusses the need for banana germplasm exploration to find sources of resistance to BBTV.

Insects associated with the banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) in banana plantations with special emphasis on the ant community

Ant attendance, well known behavior form towards aphid species was studied in case of the banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) populations in four plantations in the coastal area of Carmel (Israel), where the aphid is a major pest on banana. The study characterizes the ant community the extent of attendance and the natural enemies associate with the aphid. The ants and natural enemies were sampled on mats and suckers. The ant community in the plantations was also studied by using different ant baits. In addition, the ants’ impact on the density of the banana aphid population and the potential role of local natural enemies was evaluated in artificially infested potted banana plants set in the plantation with or without a glue barrier. More than 80% of the aphid colonies on the mats were attended by ants. Ten of the twelve ant species detected in the plantations were observed attending the banana aphid. Seventeen species of potential natural enemies of the aphid, mostly belonging to the families Syrphidae, Cecidomyiidae and Coccinellidae, were found in the aphid colonies. When ant attendance on infested potted banana plants was excluded, the number of natural enemies was higher, while the aphid density was lower, than recorded on the control plants. Our finding suggest that the ants, especially the invasive species, lower the pressure of natural enemies on the aphid population and but also probably remove large quantity of honeydew which is the source of the main damage caused by the banana aphid in the local plantations.

First Report of Banana bunchy top virus in Banana (Musa spp.) from South Africa

Bananas (Musaceae, Zingiberales) are considered to be one of the most important fruit crops and an important staple food in many developing tropical and subtropical regions (Kumar et al., 2011). In Southern Africa, banana production is under threat from a number of viral diseases, including Banana bunchy top virus (BBTV) (family Nanoviridae, genus Babuvirus). BBTV is the cause of Banana bunchy top disease, the most devastating virus disease of banana. In Sub-Saharan Africa the disease is endemic to 13 countries, including Malawi and Zambia in the Southern African sub-region. Previously, a detection survey for BBTV was done in South Africa in 1996 and this study confirmed the absence of BBTV in the Kiepersol region of Mpumalanga Province (Pietersen et al., 1996). No other surveys were conducted since then in South Africa. The disease is spread by the banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae), that is present in South Africa, and through infected propagation material. Pentalonia nigronervosa feeds on the phloem of host plants, and potentially picks up the BBTV particles from the phloem and spreads them in plantations as they feed. In June 2015, five 'Williams' plants, showing symptoms resembling BBTV, including streaks on the pseudostem and upright bunchy appearance, were submitted for identification to the Virology Diagnostic Lab at Agricultural Research Council-Plant Protection Research Institute (ARC-PPRI). The plants originated from a farm close to Hibberdene in the KwaZulu Natal South Coast production region (GPS coordinates: S 300 30, 636', E 300 30,653'). A BBTV-specific PCR was done using the protocol published by Thomson and Dietzgen (1995), using primer pairs BBT-1 and BBT-2, amplifying a fragment of the putative replicase gene. The five plants tested positive for BBTV, and the PCR products (~349 bp) of two of the accessions, 15/1408 and 15/1410, were directly sequenced using Sanger sequencing and 321 bp of both sequences were deposited in GenBank (GenBank Accession Nos: KU196167, KU196168). A non-infected banana plant was included in the test as a healthy control. Phylogenetic analyses of the partial replicase genomic region grouped accessions 15/1408 and 15/1410 with the South Pacific group that included accessions from India, Pakistan and other regions in Africa with a sequence identity of 99% (Kumar et al., 2011). A second confirmation test for the presence of BBTV in these plants was conducted using a BBTV-specific Enzyme-linked immunosorbent assay (ELISA) supplied by Agdia (Catalog number: SRA24700) using the manufacturer's instructions. The five plants tested positive for BBTV in the ELISA test, confirming the previous positive results. Forty-four additional samples were included in the ELISA test. These samples were collected randomly from 14 blocks on the same farm (GPS coordinates: S 300 30, 636', E 300 30,653') and comprised of symptomatic and non-symptomatic plants. BBTV was detected with ELISA in 34 of these plants, ten plants tested negative for BBTV. In one of these blocks, C17, all the sampled plants (4), tested negative. In three other blocks (A9, C8 and C15), positive and negative plants were recorded. In the remaining 10 blocks, all collected plants tested positive. Intense management strategies, including removal of infected plants and spraying for aphids, were implemented on the farm to prohibit the spread of the virus to neighbouring plantations. The ELISA test confirmed the earlier detection of BBTV with PCR and sequencing. This is the first report of BBTV on Musa spp. from South Africa. Strict implementation of phytosanitary measures will be necessary to prevent the spread of this virus to other regions in the country. The need to do extensive surveys for the presence of BBTV in other banana production regions in South Africa is highlighted by this finding.

First Report of Banana bunchy top virus in Banana and Plantain (Musa spp.) in Nigeria

Plantain and banana (Musa spp.) are among the most important staple crops for food and income generation for the rural and urban populations in the humid forest agroecological zone of West Africa. Until recently, Cucumber mosaic virus (genus Cucumovirus) and Banana streak virus (genus Badnavirus) were the only viruses reported to occur in Musa spp. in West Africa. In 2011, an outbreak of banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV; genus Babuvirus, family Nanoviridae) was reported in Ouémé Département (6°30'N and 2°36'E) in the Republic of Benin (2). BBTV is one of the most economically important pathogens of Musa spp. It is well established in Central Africa and also in Angola, Malawi, and Zambia in Southern Africa (2). Plants infected at early growth stages are severely dwarfed and do not bear fruit. BBTV is transmitted by the banana aphid Pentalonia nigronervosa, which is widespread in Africa (1). The regions in the Republic of Benin affected by BBTV border Ogun State (7°00'N and 3°35'E) of Nigeria. Epidemiological investigations were conducted during May 2012 at 31 locations in Ogun State to determine the potential risk of BBTV spreading into Nigeria. Plants with typical symptoms of BBTD (stunting, narrow and shortened leaves, chlorotic streaks on petioles and pseudostem) were observed in four locations: Ilashe, Odan-Itoro, Ido-Ologun, and Igbogila. Total DNA was extracted from 90 leaf samples randomly collected from symptomatic and asymptomatic banana and plantain plants in these areas. Samples were tested for BBTV by polymerase chain reaction (PCR) using primer pairs, mREP-F and mREP-R, which amplifies a 241-bp of BBTV DNA-mRep segment (1), and Scp-F and Scp-R specific for approximately 1075-bp BBTV DNA-S that encodes coat protein gene (1). The amplicons of expected size were obtained from 17 of 90 samples analyzed (18.8%). BBTV in the symptomatic plants was further confirmed by nucleic acid spot hybridization (NASH) assay using DIG-labeled 1,075-bp probe corresponding to coat protein gene and chromogenic detection as per the previously described protocol (3). The DIG-probe specifically reacted with nucleic acid from the symptomatic plants, but not with negative controls, providing conclusive evidence for the BBTV. The PCR products of DNA-mRep segment amplified from three banana plants infected with BBTV collected in Ilashe (Ipokia Local Government Area) were purified and sequenced in both directions. The sequences of these isolates were 100% identical with each other (GenBank Accession Nos. JX290301, JX290302, and JX290303). A BLASTn search revealed 100% nucleotide sequence identity with a BBTV isolate from Benin (JQ437548) and 99 to 100% identity with DNA-mRep sequences of several other BBTV isolates from Africa, Australia, India, and the South Pacific. Further analysis of the 241-bp mRep gene sequences with Neighbor-Joining phylogenetic analysis grouped the BBTV isolate with the South Pacific isolates. To our knowledge, this is the first report of BBTV in Nigeria. This underscores need for surveys to assess the extent of BBTV spread in Nigeria and strict implementation of phytosanitary measures, including restrictions on the movement of planting material from disease-affected regions, to prevent further spread of this important disease.

MOLECULAR CHARACTERIZATION AND PHYLOGENETIC STUDIES OF COMPONENT SIX OF BANANA BUNCHY TOP BABUVIRUS (BBTV DNA-6)

Banana and plantations (Musa sp.) are the most fourth most important global food crop after rice, wheat and maize (Piertersen and Thomas, 2001). Banana plantations are subjected to various natural climates but diseases; in particular, viral diseases constitute a major setback to this crop worldwide. Among viral infections, Banana Bunchy Top Virus (BBTV) is the most serious virus affecting banana in Egypt as well as the world (Dale, 1987; Othman et al., 1996; Harish et al., 2008) and is responsible for the massive reduction in banana crop yield. The symptoms of BBTD are yellowing, dark green streaks on midrib, petioles, extending down into pseudostem, dark green dots and dashes along the minor leaf veins, stunted growth with bunchy top appearance (Magee, 1940; Vetten et al., 2005). BBTV belong to genus Babuvirus and family Nanoviridae with isometric particles of 18-20 nm in diameter. It is naturally transmitted, in persistence manner, by banana aphid Pentalonia nigronervosa (Hu et al., 1996). BBTV is identified as a phloem-limited virus used to occur in low concentration in banana-infected plants (Harding et al., 1991 and 2000). The virus has a single coat protein with molecular weight (Mr.) of about 20-21kDa (Dietzgen and Thomas, 1991; Harding et al., 1991; Sadik et al., 1999).The viron consists of at least six components of circular ssDNA each component of the BBTV genome contains one large (monocistronic) transcriptional active open reading frame (ORF) except BBTV DNA 1 contains two ORFs one master replication protein (Rep) ORF (Hafner et al., 1997) and a small ORF internal to major ORF (Beetham et al., 1997). Additionally, two conserved region: stem-loop common region (CR-SL) and major common region (CR-M), potential TATA box at 3 ' of the stem-loop and polyadenylation signal (Burns et al., 1995; Beetham et al., 1997 and 1999).The nucleotide sequence of the component six of Australian isolate BBTV has 1089 nt. (Burns et al., 1995). The encoded protein of BBTV DNA-6 is a nuclear shuttle protein and is preferentially targeted to the nucleus when expressed alone however in the presence of the movement protein it targeted to the cell periphery (Wanitchakorn et al., 2000a).The aim of this study is to amplify, clone and sequence the full length of BBTV DNA-6 and compare it with other published sequences of the corresponding sequence.

Differential expression of pathogenesis-related proteins and defense enzymes in banana: interaction between endophytic bacteria, Banana bunchy top virus and Pentalonia nigronervosa

Banana bunchy top disease caused by Banana bunchy top virus is the most serious viral disease of banana and plantain worldwide. The virus is transmitted by the aphid vector Pentalonia nigronervosa in a persistent manner. This paper deals with the effect of the interaction between plant growth promoting endophytic bacteria, Banana bunchy top virus, and the banana aphid Pentalonia nigronervosa in the expression of Pathogenesis-related proteins (PR-proteins) and defense enzymes in banana. The existence of virus in the aphids was confirmed by ELISA, DIBA and PCR. PCR could amplify 1100-bp replicase gene of BBTV from viruliferous aphids. A significant increase in the enzymatic activity of all measured PR proteins and defense enzymes, as compared to control plants, was seen in the plants inoculated with endophytic bacteria and challenged with viruliferous aphids. Native gel electrophoresis revealed expression of more isoforms of PR proteins viz., peroxidase and chitinase in the banana plants challenged with mixtures of plant growth promoting endophytic bacteria and viruliferous aphids. Enhanced activity of a PR-2 protein viz., β-1,3-glucanase was also noticed in the viruliferous aphids infested plants. Some of the defense-related enzymes viz., Polyphenol oxidase and Phenylalanine ammonia lyase and phenolic compounds were also upregulated, up to 5 days after aphid infestation and thereafter there was a reduction in the enzymatic activity. Thus, there exist a differential accumulation of PR proteins and defense-related enzymes, when there is tri-tropic interaction between endophytic bacteria, virus, and insect and the role of the endophytic bacteria in the defense mechanisms against insect pests needs to be elucidated.

Ant‐attendance as a critical factor in the biological control of the banana aphid Pentalonia nigronervosa Coq. (Hom. Aphididae) in Oceania

Abstract: Colonies of the banana aphid Pentalonia nigronervosa Coq. were heavily attended by ants in banana plantations on Tongatapu Island, Kingdom of Tonga. Ant‐attendance reduced the density of indigenous predators of P. nigronervosa considerably. Most important was the reduction by ants of the parasitism of Aphis gossypii by the aphelinid wasp Aphelinus gossypii. The introduced aphid parasitoid Aphidius colemani was also heavily attacked by various ant species, and we conclude that ant‐attendance may limit the economic impact of this successfully introduced parasitoid species.

Suitability of five species of Aphidiidae (hymenoptera) for the biological control of the banana aphidPentalonia nigronervosacoq. (Homoptera, Aphididae) in the south pacific

Abstract Five aphid parasitoids were tested for their suitability as biocontrol agents of the banana aphid Pentalonia nigronervosa Coq.: Lysiphlebus testaceipes, Lysiphlebus fabarum, Trioxys angelicae, Aphidius colemani and Ephedrus plagiator. L. testaceipes and A. colemani were successfully mass‐reared on P. nigronervosa for five generations in the laboratory. Both species showed no obvious preferences for certain host instars or morphs (apteriform or alatiform larvae). Their capability to alternate between P. nigronervosa and Aphis fabae did not diminish within five generations. It is concluded that both species could have the potentials of suitable biological control agents against P. nigronervosa. Screening of two other parasitoids (E. plagiator and L. fabarum) is promising.