Vector Biology Research Papers - Academia.edu (original) (raw)

SUMMARY Control of grapevine virus and phytoplasma diseases is currently based on prophylactic measures and cultur- al practices. Certification programs aim to avoid the in- troduction of diseased grapevines into healthy vine- yards, and... more

SUMMARY Control of grapevine virus and phytoplasma diseases is currently based on prophylactic measures and cultur- al practices. Certification programs aim to avoid the in- troduction of diseased grapevines into healthy vine- yards, and cultural practices aim to reduce the popula- tions of virus vectors to limit virus spread. These ap- proaches however are of limited effectiveness. Addition- ally, there

Larval mosquito collection was performed in Barangay Binubusan, Lian Municipality, Batangas Province during the last quarter of 2008 from October to December to determine the mosquito populations present in the area. Mosquito larvae were... more

Larval mosquito collection was performed in Barangay Binubusan, Lian Municipality, Batangas Province during the last quarter of 2008 from October to December to determine the mosquito populations present in the area. Mosquito larvae were collected from various habitats, namely: rice paddy, sunny pond, open residential canal, shaded pond, and abandoned tire. A dichotomous key was devised for the identification of local mosquito fauna. A total of 1,128 mosquito larvae were collected during the study period, comprising 958 (84.93%) Culex, 125 (11.08%) Aedes, and 45 (3.99%) Anopheles. The highest larval collection was recorded in November consisting of 100% Culex spp. Five Culex species were identified: Culex quinquefasciatus (51.86%), Culex vishnui (14.0%), Culex tritaeniorhynchus (9.84%), Culex whitmorei (8.78%) and the first reported presence of Culex mimeticus (0.53%) in the country. Aedes species were represented by Aedes vexans (5.94%), Aedes aegypti (4.34%), and Aedes niveus (0.80%). Anopheline mosquitoes were represented only by Anopheles flavoristris (3.99%). Of the species identified, only Ae. aegypti and An. flavirostris have been documented of public health importance in the country.

Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has... more

Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has emerged in the last two decades as one of the major factors affecting grape fruit quality, leading to research efforts aimed at reducing its economic impact. Most research has focused on the pathogens themselves, such as improved detection protocols, with limited work directed toward disease ecology and the development of management practices. Here we discuss the ecology and management of GLD, focusing primarily on Grapevine leafroll-associated virus 3, the most important virus species within the complex. We contextualize research done on this system within an ecological framework that forms the backbone of the discussion regarding current and potential GLD management strategies. To reach this goal, we introduce various aspects of GLD biology and ecology...

Background & objectives: Artificial water-holding containers (AWHCs) have been well-documented in many Aedes aegypti studies for dengue surveillance and developmental research. Hence, we investigated the role of different AHWCs on the... more

Background & objectives: Artificial water-holding containers (AWHCs) have been well-documented in many
Aedes aegypti studies for dengue surveillance and developmental research. Hence, we investigated the role of
different AHWCs on the development and ecdysis period of Ae. aegypti dengue vector, a container breeding
mosquito.
Methods: Nine types of AWHCs, namely glass, polystyrene foam, rubber, steel, porcelain, plastic, aluminum,
clay and concrete, were chosen for the study. All AWHCs were subjected to the developmental assay for an
observation period of 10 days. Regression and hazard analyses were employed to the developmental stages and
the characteristics of the AWHCs.
Results: The observations revealed that Ae. aegypti development is fastest in glass and polystyrene containers
while slowest in concrete containers. Moreover, pupal ecdysis appears to be the most affected by the characteristics
of the AWHCs based on regression and hazard analyses.
Interpretation & conclusion: Characteristics of the container that can regulate water temperature seem to be the
driving force with regards to the slow or fast development of Ae. aegypti, more notably in pupal ecdysis. The
results of the study further strengthen our understanding on the dynamics of Ae. aegypti’s developmental biology
to different characteristics of artificial water containers. This, in turn, would aid in devising vector control strategies
against dengue especially in endemic areas.

Feeding on the blood of vertebrates is a risky task for haematophagous insects and it can be reasonably assumed that it should also be costly in terms of energetic expenditure. Blood circulates inside vessels and it must be pumped through... more

Feeding on the blood of vertebrates is a risky task for haematophagous insects and it can be reasonably assumed that it should also be costly in terms of energetic expenditure. Blood circulates inside vessels and it must be pumped through narrow tubular stylets to be ingested. We analysed the respiratory pattern and the energetic cost of taking a blood meal in Rhodnius prolixus using flow-through and stop-flow respirometry to measure carbon dioxide emission, oxygen consumption and water loss before and during feeding. We observed an increase of up to 17-fold in the metabolic rate during feeding and a change in the respiratory pattern, which switched from a discontinuous cyclic pattern during resting to a continuous pattern when the insects started to feed, remaining in this condition unchanged for several hours. The energetic cost of taking a meal was significantly higher when bugs fed on a living host, compared with feeding on an artificial feeder. No differences were observed between feeding on blood or on saline solution in vitro, revealing that the substrate for feeding (vessels versus membrane) and not the nature of the fluid was responsible for such a difference in the energetic cost. Water loss significantly increased during feeding, but did not vary with feeding method or type of food. The mean respiratory quotient in resting bugs was 0.83, decreasing during feeding to 0.52. These data constitute the first metabolic measures of an insect during blood feeding and provide the first insights into the energetic expenditure associated with haematophagy.

Owing to the implementation of a national malaria elimination programme from 2010 to 2020, we performed a systematic review to assess research challenges in the People's Republic of China (P.R. China) and define research priorities in... more

Owing to the implementation of a national malaria elimination programme from 2010 to 2020, we performed a systematic review to assess research challenges in the People's Republic of China (P.R. China) and define research priorities in the next few years. A systematic search was conducted for articles published from January 2000 to December 2012 in international journals from PubMed and Chinese journals from the China National Knowledge Infrastructure (CNKI). In total, 2532 articles from CNKI and 308 articles from PubMed published between 2010 and 2012 related to malaria after unrelated references and review or comment were further excluded, and a set of research gaps have been identified that could hinder progress toward malaria elimination in P.R. China. For example, there is a lack of sensitive and specific tests for the diagnosis of malaria cases with low parasitemia, and there is a need for surveillance tools that can evaluate the epidemic status for guiding the elimination ...

http://philjournalsci.dost.gov.ph/vol141no1/pdf/Medically%20important%20mosquitoes%20identified%20in%20Binubusan.pdf Larval mosquito collection was performed in Barangay Binubusan, Lian Municipality, Batangas Province during the last quarter of 2008 from October to December to determine the mosquito populations present in the area. Mosquito larvae were collected from various habitats, namely: rice paddy, sunny pond, open residential canal, shaded pond, and abandoned tire. A dichotomous key was devised for the identification of local mosquito fauna. A total of 1,128 mosquito larvae were collected during the study period, comprising 958 (84.93%) Culex, 125 (11.08%) Aedes, and 45 (3.99%) Anopheles. The highest larval collection was recorded in November consisting of 100% Culex spp. Five Culex species were identified: Culex quinquefasciatus (51.86%), Culex vishnui (14.0%), Culex tritaeniorhynchus (9.84%), Culex whitmorei (8.78%) and the first reported presence of Culex mimeticus (0.53%)...

Virions of beet western yellows luteovirus contain a major capsid protein (P22.5) and a minor readthrough protein (P74), produced by translational readthrough of the major capsid protein sequence into the neighboring open reading frame,... more

Virions of beet western yellows luteovirus contain a major capsid protein (P22.5) and a minor readthrough protein (P74), produced by translational readthrough of the major capsid protein sequence into the neighboring open reading frame, which encodes the readthrough domain (RTD). The RTD contains determinants required for efficient virus accumulation in agroinfected plants and for aphid transmission. The C-terminal halves of the RTD are not well conserved among luteoviruses but the N-terminal halves contain many conserved sequence motifs, including a proline-rich sequence separating the rest of the RTD from the sequence corresponding to the major coat protein. To map different biological functions to these regions, short in-frame deletions were introduced at different sites in the RTD and the mutant genomes were transmitted to protoplasts as transcripts and to Nicotiana clevelandii by agroinfection. Deletions in the nonconserved portion of the RTD did not block aphid transmission bu...

Phlebotomus papatasi sand flies are among the primary vectors of Leishmania major parasites from Morocco to the Indian subcontinent and from southern Europe to central and eastern Africa. Antibody based immunity to sand fly salivary gland... more

Phlebotomus papatasi sand flies are among the primary vectors of Leishmania major parasites from Morocco to the Indian subcontinent and from southern Europe to central and eastern Africa. Antibody based immunity to sand fly salivary gland proteins among pre-exposed human populations remains a complex contextual problem that, while heavily investigated, is not yet fully understood. We profiled the immunoreactivities of plasma antibodies to sand fly salivary gland sonicates (SGS) from 229 human blood donors residing in different regions of sand fly endemicity throughout Jordan and Egypt, as well as 69 United States military personnel stationed in Iraq in 2007, who were differentially exposed to P. papatasi bites and L. major infections. Compared to plasma from control region donors, antibodies were significantly immunoreactive to five salivary proteins (12, 26, 30, 38, 44 kDa) among Jordanian and Egyptian donors, with IgG4 being the dominant anti-SGS isotype. U.S. personnel plasma were significantly immunoreactive to only two salivary proteins (38 and 14 kDa). Using k-means clustering, donors were segregated into four clusters distinguished by unique immunoreactivity profiles to varying combinations of the significantly immunogenic salivary proteins. SGS induced cellular proliferation was diminished among donors residing in sand fly endemic regions. These data provide a clearer picture of human immune responses to sand fly vector salivary constituents.

<p>The MSP1a sequences from tick-transmissible and non-transmissible strains (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065243#pone-0065243-t002&quot; target="_blank">Table 2</a>) were included in the phylogenetic analysis. The phylogenetic tree was reconstructed using the neighbor joining and maximum likelihood methods. Reliability for internal branch was assessed using the bootstrapping method with 1000 bootstrap replicates. Bootstrap values are shown as % in the internal branch. The tree shows four phylogenetic clusters containing different patterns of MSP1a tandem repeat 2D structures. Cluster β-α-c (blue), cluster α-1 and cluster α-2 (beige) contain tick-transmissible A. marginale strains while in cluster β (red) fall the non-tick-transmissible strains.</p

Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has... more

Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has emerged in the last two decades as one of the major factors affecting grape fruit quality, leading to research efforts aimed at reducing its economic impact. Most research has focused on the pathogens themselves, such as improved detection protocols, with limited work directed toward disease ecology and the development of management practices. Here we discuss the ecology and management of GLD, focusing primarily on Grapevine leafroll-associated virus 3, the most important virus species within the complex. We contextualize research done on this system within an ecological framework that forms the backbone of the discussion regarding current and potential GLD management strategies. To reach this goal, we introduce various aspects of GLD biology and ecology...

Owing to the implementation of a national malaria elimination programme from 2010 to 2020, we performed a systematic review to assess research challenges in the People's Republic of China (P.R. China) and define research priorities in... more

Owing to the implementation of a national malaria elimination programme from 2010 to 2020, we performed a systematic review to assess research challenges in the People's Republic of China (P.R. China) and define research priorities in the next few years. A systematic search was conducted for articles published from January 2000 to December 2012 in international journals from PubMed and Chinese journals from the China National Knowledge Infrastructure (CNKI). In total, 2532 articles from CNKI and 308 articles from PubMed published between 2010 and 2012 related to malaria after unrelated references and review or comment were further excluded, and a set of research gaps have been identified that could hinder progress toward malaria elimination in P.R. China. For example, there is a lack of sensitive and specific tests for the diagnosis of malaria cases with low parasitemia, and there is a need for surveillance tools that can evaluate the epidemic status for guiding the elimination ...

The insecticide resistance status of Culex quinquefasciatus Say (Diptera: Culicidae) to DDT and deltamethrin across army cantonments and neighbouring villages in northeastern India was investigated. In India, DDT is still the insecticide... more

The insecticide resistance status of Culex quinquefasciatus Say (Diptera: Culicidae) to DDT and deltamethrin across army cantonments and neighbouring villages in northeastern India was investigated. In India, DDT is still the insecticide of choice for public health programmes. In military stations, pyrethroids, especially deltamethrins, are used for insecticide-treated nets (ITNs). Recent information on the levels of resistance to DDT and deltamethrin in mosquito populations of northeastern India is scare. Continued monitoring of insecticide resistance status, identification of the underlying mechanisms of resistance in local mosquito populations and the establishment of a baseline data bank of this information are of prime importance. Insecticide susceptibility assays were performed on wild-caught adult female Cx. quinquefasciatus mosquitoes to the discriminating doses recommended by the World Health Organisation (WHO) to DDT (4%) and deltamethrin (0.05%). Across all study sites, mortality as a result of DDT varied from 11.9 to 50.0%, as compared with 91.2% in the susceptible laboratory strain (S-Lab), indicating that Cx. quinquefasciatus is resistant to DDT. The species was found to be 100% susceptible to deltamethrin in all study sites except Benganajuli and Rikamari. Knock-down times (KDT) in response to deltamethrin varied significantly between study sites (P < 0.01) from 8.3 to 17.8 min for KDT50 and 37.4 to 69.5 min for KDT90. All populations exceeded the threshold level of alpha-esterase, beta-esterase and glutathion S-transferase (GST) established for the S-Lab susceptible strain, and all populations had 100% elevated esterase and GST activity, except Missamari and Solmara. Beta-esterase activity in Field Unit II (96.9%) was less than in any of the other populations. Benganajuli had the highest activity level for all the enzymes tested. There was a significant correlation between all enzyme activity levels and insecticide resistance phenotype by populations (P < 0.05). The results presented here provide the first report and baseline information of the insecticide resistance status of Cx. quinquefasciatus in northeastern India, and associated information about biochemical mechanisms that are essential for monitoring the development of insecticide resistance in the area.

The two Old World genera, Phlebotomus and Sergentomyia, were both recorded in southern Anatolia in Turkey. Phlebotomus species predominated and comprised about 93% of the entire collection (3,172 specimens). Out of the sixteen species... more

The two Old World genera, Phlebotomus and Sergentomyia, were both recorded in southern Anatolia in Turkey. Phlebotomus species predominated and comprised about 93% of the entire collection (3,172 specimens). Out of the sixteen species identified, two belonged to the genus Sergentomyia: S. dentata and S. theodori. The remaining fourteen species in the genus Phlebotomus were grouped under four subgenera including some species that are elsewhere known to act as vectors of human cutaneous leishmaniasis. Most of the Phlebotomus were P. tobbi (32.5%), but P. papatasi, P. transcaucasicus, P. halepensis, P. galilaeus, P. sergenti, P. syriacus, P. neglectus, P. simici, P. alexandri, P. similis, P jacusieli, P. perfiliewi, and P. brevis were also identified. There were two associations of sand fly fauna with altitudinal gradient; the first one at relatively higher altitudes and the second one at lower altitudes. The transition between these two assemblages was within the range of 800-1,000 m. It is likely that Adana and Hatay provinces are transitional areas between western and eastern Anatolia. Mountains do not appear to be important geographical barriers for sand fly distribution. We also found that the proven vector P. sergenti is a widely distributed species throughout southern Anatolia and this species, together with its closely related species P. similis, shows sympatry in Konya Province.

Beet western yellows luteovirus is obligately transmitted by the aphid Myzus persicae in a circulative, non-propagative fashion. Virus movement across the epithelial cells of the digestive tube into the hemocoel and from the hemocoel into... more

Beet western yellows luteovirus is obligately transmitted by the aphid Myzus persicae in a circulative, non-propagative fashion. Virus movement across the epithelial cells of the digestive tube into the hemocoel and from the hemocoel into the accessory salivary glands is believed to occur by receptor-mediated endocytosis and exocytosis. Virions contain two types of protein; the major 22 kDa capsid protein and the minor read-through protein, P74, which is composed of the major capsid protein fused by translational read-through to a long C-terminal extension called the read-through domain. Beet western yellows virus carrying various mutations in the read-through domain was tested for its ability to be transmitted to test plants by aphids fed on agro-infected plants and semi-purified or purified virus preparations. The results establish that the read-through domain carries determinants that are essential for aphid transmission. The findings also reveal that the read-through domain is i...