Larval Breeding Sites of Lutzomyia longipalpis (Diptera: Psychodidae) in Visceral Leishmaniasis Endemic Urban Areas in Southeastern Brazil

Background

The scarcity of information on the immature stages of sand flies and their preferred breeding sites has resulted in the focus of vectorial control on the adult stage using residual insecticide house-spraying. This strategy, along with the treatment of human cases and the euthanasia of infected dogs, has proven inefficient and visceral leishmaniasis continues to expand in Brazil. Identifying the breeding sites of sand flies is essential to the understanding of the vector''s population dynamic and could be used to develop novel control strategies.

Methodology/Principal finding

In the present study, an intensive search for the breeding sites of Lutzomyia longipalpis was conducted in urban and peri-urban areas of two municipalities, Promissão and Dracena, which are endemic for visceral leishmaniasis in São Paulo State, Brazil. During an exploratory period, a total of 962 soil emergence traps were used to investigate possible peridomiciliary breeding site microhabitats such as: leaf litter under tree, chicken sheds, other animal sheds and uncovered debris. A total of 160 sand flies were collected and 148 (92.5%) were L. longipalpis. In Promissão the proportion of chicken sheds positive was significantly higher than in leaf litter under trees. Chicken shed microhabitats presented the highest density of L. longipalpis in both municipalities: 17.29 and 5.71 individuals per square meter sampled in Promissão and Dracena respectively. A contagious spatial distribution pattern of L. longipalpis was identified in the emergence traps located in the chicken sheds.

Conclusion

The results indicate that chicken sheds are the preferential breeding site for L. longipalpis in the present study areas. Thus, control measures targeting the immature stages in chicken sheds could have a great effect on reducing the number of adult flies and consequently the transmission rate of Leishmania (Leishmania) infantum chagasi.     

Evaluation of efficacy of impregnated curtains in experimental hen houses as a phlebotomine control tool in northeast Argentina

The aim of this study was to evaluate the effectiveness of insecticide‐impregnated curtains against the entry of phlebotomine (Diptera: Psychodidae) flies into experimental slatted hen houses in an area endemic for American cutaneous leishmaniasis (ACL). Three treatments in experimental dwellings containing three chickens each were applied using, respectively, an impregnated curtain (IC), a non‐impregnated curtain (NIC) and no curtain (NC). A control site without chickens (WC) was included. The study used permethrin at 0.05 g/m². During each month for 1 year, each experimental hen house randomly received all treatments. Phlebotomine sandflies were captured using REDILA BL traps placed inside the hen house. Significant differences in abundances of phlebotomine flies/trap/night were observed between treatments (χ² = 17853.58, d.f. = 3, P < 0.0001): 59.7% of phlebotomines were captured in the NC treatment, 26.3% in the NIC treatment, 8.0% in the IC treatment and 6.1% in the WC condition. Nyssomyia whitmani (Antunes & Coutinho) was the most abundant species in all collections (89.9%). These results showed a lower abundance of phlebotomines in the experimental hen house in the IC condition than in the hen house in the NC condition (P < 0.05) and that the presence of NIC represents an effective physical barrier against phlebotomines (P < 0.05). Therefore, the use of curtains may be an alternative eco‐friendly method for the prevention of indoor ACL transmission in slatted dwellings, which represent a common house type in northeast Argentina.     

Phlebotomine fauna,natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara,state of Mato Grosso, Brazil

Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.     

The phlebotomine fauna (Diptera: Psychodidae) of Guaraí, state of Tocantins,with an emphasis on the putative vectors of American cutaneous leishmaniasis in rural settlement and periurban areas

Phlebotomine sandflies were captured in rural settlement and periurban areas of the municipality of Guaraí in the state of Tocantins (TO), an endemic area of American cutaneous leishmaniasis (ACL). Forty-three phlebotomine species were identified, nine of which have already been recognised as ACL vectors. Eleven species were recorded for the first time in TO. Nyssomyia whitmani was the most abundant species, followed by Evandromyia bourrouli, Nyssomyia antunesi and Psychodopygus complexus. The Shannon-Wiener diversity index and the evenness index were higher in the rural settlement area than in the periurban area. The evaluation of different ecotopes within the rural area showed the highest frequencies of Ev. bourrouli and Ny. antunesi in chicken coops, whereas Ny. whitmani predominated in this ecotope in the periurban area. In the rural settlement area, Ev. bourrouli was the most frequently captured species in automatic light traps and Ps. complexus was the most prevalent in Shannon trap captures. The rural settlement environment exhibited greater phlebotomine biodiversity than the periurban area. Ps. complexus and Psychodopygus ayrozai naturally infected with Leishmania (Viannia) braziliensis were identified. The data identified Ny. whitmani as a potential ACL vector in the periurban area, whereas Ps. complexus was more prevalent in the rural environment associated with settlements.     

Sandflies (Diptera: Psychodidae) in rural and urban environments in an endemic area of cutaneous leishmaniasis in southern Brazil

The high proportion of cases of cutaneous leishmaniasis reported amongst residents in the city of Bandeirantes, in the state of Paraná, Brazil, led the authors to investigate the phlebotomine fauna in both urban and rural environments. The sandflies were captured with automatic light traps from 07:00 pm-07:00 am fortnightly in 11 urban peridomiciles from April 2008-March 2009 and monthly in three ecotopes within four rural localities from April 2009-March 2010. In one of these latter localities, sandfly capture was conducted with white/black Shannon traps during each of three seasons: spring, summer and fall. A total of 5,729 sandflies of 17 species were captured. Nyssomyia neivai (46.7%) and Nyssomyia whitmani (35.3%) were the predominant species. In this study, 3,865 specimens were captured with automatic light traps: 22 (0.083 sandflies/trap) in the urban areas and 3,843 (26.69 sandflies/trap) in the rural areas. Ny. neivai was predominant in urban (68.2%) and rural (42.8%) areas. A total of 1,864 specimens were captured with the white/black Shannon traps and Ny. neivai (54.5%) and Ny. whitmani (31.4%) were the predominant species captured. The small numbers of sandflies captured in the urban areas suggest that the transmission of Leishmania has occurred in the rural area due to Ny. neivai and Ny. whitmani as the probable vectors.     

Larval habitats of sand flies in rural areas of southern Brazil

We report the results of an investigation of natural larval sand fly habitats in the Recanto Marista, Doutor Camargo municipality, Paraná state, Brazil, from May, 2010 to August, 2012. We used Alencar emergence traps (AT), experimental traps (ET), and soil samples incubated in a biochemical oxygen demand incubator. Eight sand flies were collected with ATs. One specimen was collected with an ET and 21 were collected in soil samples. The collected species were Brumptomyia brumpti, Micropygomyia ferreirana, Migonemyia bursiformis, Migonemyia migonei, Nyssomyia neivai, Nyssomyia whitmani, and Pintomyia pessoai. The laval habitats of sand flies were located in the Recanto Marista, especially between tree roots, but the number of adults that emerged in the traps and soil samples was small despite the high density of sand flies that has been recorded in the Recanto Marista.     

Ecological interactions among phlebotomines (Diptera: Psychodidae) in an agroforestry environment of northeast Brazil

Phlebotomine vectors transmit parasites and can cause visceral leishmaniasis (VL) or cutaneous leishmaniasis (TL). Phlebotomine females are hematophagous but need to ingest carbohydrates, possibly promoting the development of protozoan parasites in their digestive tract. The present study evaluated the species composition and abundance across several habitats in a metropolitan landscape, as well as associations among phlebotomines, plants, and local climatic parameters. Three consecutive monthly collections were carried out in an Atlantic Forest fragment, using CDC light traps in peridomestic areas and cashew, coconut, and mango tree. plantations. Eight species of phlebotomine were captured: Evandromyia evandroi, Lutzomyia longipalpis, Psathyromyia shannoni, Sciopemyia sordellii, Evandromyia walkeri, Psychodopygus wellcomei, Nyssomyia whitmani, and Nyssomyia intermedia, primarily from the forest environment. L. longipalpis was confirmed as a species adapted to anthropic environments, while P. wellcomei was shown to be predominately forest‐dwelling. Phlebotomines exhibited diversified food consumption patterns in relation to carbohydrate sources. They fed on both native and exotic species of arboreal and shrubby vegetables and gramineous plants.     

Detection of Leishmania DNA in phlebotomines captured in Campo Grande, Mato Grosso do Sul, Brazil

Over the past years, leishmaniases have become a public health issue in the Brazilian state of Mato Grosso do Sul, particularly in Campo Grande, the state capital. The purpose of this study was to detect the presence of Leishmania DNA in the population of phlebotomine sandflies using DNA amplification by PCR. Insect captures were carried out from 4 pm. to 7 am for 4 consecutive days each month from October 2005 to September 2006 in 16 neighborhoods located in 7 urban regions of Campo Grande. Traps were placed indoors and in the vicinity of households. As many as 971 males and 203 females were collected. One hundred and five naturally fed females were identified and grouped as 1- to 4-specimen pools. DNA extraction was carried out using whole insects. Lutzomyia longipalpis predominated, accounting for 99.15% of the phlebotomines captured. Also found was Nyssomyia whitmani, the vector of tegumentary leishmaniasis. Abundance was greatest in the vicinity of households (69.8% of the phlebotomines captured). As revealed by PCR, parasites were present in 1.9% of the Leishmania spp. specimens investigated and confirmed for visceral leishmaniasis.     

Ny-1 and Ny-2 genes conferring hypersensitive response to potato virus Y (PVY) in cultivated potatoes: mapping and marker-assisted selection validation for PVY resistance in potato breeding

Potato virus Y (PVY) is one of the most important viruses affecting potato (Solanum tuberosum) production. In this study, a novel hypersensitive response (HR) gene, Ny-2, conferring resistance to PVY was mapped on potato chromosome XI in cultivar Romula. In cultivars Albatros and Sekwana, the Ny-1 gene was mapped on chromosome IX. In cv. Romula, the local lesions appeared in leaves inoculated with the PVY^N-Wi isolate at 20 and 28 °C; PVY systemic infections were only occasionally observed at the higher temperature. In cvs. Albatros and Sekwana, expression of the necrotic reaction to virus infection was temperature-dependent. PVY^N-Wi was localized at 20 °C; at 28 °C, the systemic, symptomless infection was observed. We developed the B11.6₁₆₀₀ marker co-segregating with Ny-2 and the S1d11 marker specific for the Ny-1 gene. Fifty potato cultivars were tested with markers B11.6 and S1d11 and marker SC895 linked to the Ny-1 gene in cv. Rywal. These results indicated the utility of these markers for marker-assisted selection of HR-like PVY resistance in potato breeding programs.     

Molecular Detection of Leishmania in Phlebotomine Sand Flies (Diptera: Psychodidae) from a Cutaneous Leishmaniasis Focus at Xakriabá Indigenous Reserve,Brazil

Autochthonous cases of American cutaneous leishmaniasis (ACL) have been reported since 2001 in the Xakriabá Indigenous Reserve located in the municipality of São João das Missões in northern Minas Gerais state, Brazil. In order to study the presence of Leishmania DNA in phlebotomine sand flies, six entomological collections were carried out from July 2008 through July 2009, using 40 light traps placed in peridomicile areas of 20 randomly selected houses. From October 2011 through August 2012, another six collections were carried out with 20 light traps distributed among four trails (five traps per trail) selected for a previous study of wild and synanthropic hosts of Leishmania. A total of 4,760 phlebotomine specimens were collected belonging to ten genera and twenty-three species. Single female specimens or pools with up to ten specimens of the same locality, species and date, for Leishmania detection by molecular methods. Species identification of parasites was performed with ITS1 PCR-RFLP using HaeIII enzyme and genetic sequencing for SSU rRNA target. The presence of Leishmania DNA was detected in eleven samples from peridomicile areas: Lu. longipalpis (two), Nyssomyia intermedia (four), Lu. renei (two), Lu. ischnacantha, Micropygomyia goiana and Evandromyia lenti (one pool of each specie). The presence of Leishmania DNA was detected in twelve samples from among the trails: Martinsmyia minasensis (six), Ny. intermedia (three), Mi. peresi (two) and Ev. lenti (one). The presence of Leishmania infantum DNA in Lu. longipalpis and Leishmania braziliensis DNA in Ny. intermediasupport the epidemiological importance of these species of sand flies in the cycle of visceral and cutaneous leishmaniasis, respectively. The results also found other species associated with Leishmania DNA, such as Mt. minasensis and Ev. lenti, which may participate in a wild and/or synanthropic cycle of Leishmania transmission in the studied area.     

Raspberry ketone-supplemented diet has no effect on fitness parameters or lure responsiveness in male melon flies,Zeugodacus cucurbitae (Diptera: Tephritidae)

The male annihilation technique (MAT) and sterile insect technique (SIT) are often used to control pestiferous tephritid fruit flies (Diptera: Tephritidae). MAT involves the deployment of traps containing a male attractant and insecticide with the goal of drastically reducing male abundance and ultimately eliminating the entire population. SIT, which involves the mass production, sterilization, and release of the target species, may also be implemented to achieve final extirpation. Generally, simultaneous implementation of MAT and SIT is counterproductive, because the presence of large numbers of male-specific traps in the environment (MAT) would greatly reduce the number of sterile males available for copulating with wild females (SIT). However, studies on the Queensland fruit fly, Bactrocera tryoni (Froggatt), indicate that concurrent use of MAT and SIT may be feasible. Sexually mature males of B. tryoni are attracted to the raspberry ketone and its synthetic analogue cue-lure. Males of B. tryoni fed raspberry-ketone-supplemented diet when newly emerged showed lower attraction to cue-lure baited traps than control males. In addition, newly emerged males provided this diet displayed accelerated sexual maturation, which would allow the early release of sterile males and reduce pre-release holding costs. Here, we examined whether the addition of raspberry ketone to the adult diet of male melon flies, Zeugodacus cucurbitae (Coquillett), produced effects similar to those observed for B. tryoni. Despite using similar methods, no significant effect of raspberry ketone-supplemented diet on time to sexual maturity, survival, mating competitiveness, or attraction to cue-lure baited traps in mass-reared Z. cucurbitae males.     

Performance of light‐emitting diode traps for collecting sand flies in entomological surveys in Argentina

The performance of two light‐emitting diode traps with white and black light for capturing phlebotomine sand flies, developed by the Argentinean Leishmaniasis Research Network (REDILA‐WL and REDILA‐BL traps), were compared with the traditional CDC incandescent light trap. Entomological data were obtained from six sand fly surveys conducted in Argentina in different environments. Data analyses were conducted for the presence and the abundance of Lutzomyia longipalpis, Migonemyia migonei, and Nyssomyia whitmani (106 sites). No differences were found in presence/absence among the three types of traps for all sand fly species (p>0.05). The collection mean of Lu. longipalpis from the REDILA‐BL didn´t differ from the CDC trap means, nor were differences seen between the REDILA‐WL and the CDC trap collection means (p>0.05), but collections were larger from the REDILA‐BL trap compared to the REDILA‐WL trap (p<0.05). For Mg. migonei and Ny. whitmani, no differences were found among the three types of traps in the number of individuals captured (p>0.05). These results suggest that both REDILA traps could be used as an alternative capture tool to the original CDC trap for surveillance of these species, and that the REDILA‐BL will also allow a comparable estimation of the abundance of these flies to the CDC light trap captures. In addition, the REDILA‐BL has better performance than the REDILA‐WL, at least for Lu. longipalpis.     

Comparison of sand fly trapping approaches for vector surveillance of Leishmania and Bartonella species in ecologically distinct,endemic regions of Peru

BackgroundIn Peru, the information regarding sand fly vectors of leishmaniasis and bartonellosis in the Amazon region is limited. In this study, we carried out sand fly collections in Peruvian lowland and highland jungle areas using different trap type configurations and screened them for Leishmania and Bartonella DNA.Methodology/Principal findingsPhlebotomine sand flies were collected in Peruvian Amazon jungle and inter Andean regions using CDC light trap, UV and color LED traps, Mosquito Magnet trap, BG Sentinel trap, and a Shannon trap placed outside the houses. Leishmania spp. screening was performed by kDNA PCR and confirmed by a nested cytochrome B gene (cytB) PCR. Bartonella spp. screening was performed by ITS PCR and confirmed by citrate synthase gene (gltA). The PCR amplicons were sequenced to identify Leishmania and Bartonella species.UV and Blue LED traps collected the highest average number of sand flies per hour in low jungle; UV, Mosquito Magnet and Shannon traps in high jungle; and Mosquito Magnet in inter Andean region. Leishmania guyanensis in Lutzomyia carrerai carrerai and L. naiffi in Lu. hirsuta hirsuta were identified based on cytB sequencing. Bartonella spp. related to Bartonella bacilliformis in Lu. whitmani, Lu. nevesi, Lu. hirsuta hirsuta and Lu. sherlocki, and a Bartonella sp. related to Candidatus B. rondoniensis in Lu. nevesi and Lu. maranonensis were identified based on gltA gene sequencing.Conclusions/SignificanceUV, Blue LED, Mosquito Magnet and Shannon traps were more efficient than the BG-Sentinel, Green, and Red LED traps. This is the first report of L. naiffi and of two genotypes of Bartonella spp. related to B. bacilliformis and Candidatus B. rondoniensis infecting sand fly species from the Amazon region in Peru.     

Rickettsial agents detected in the genus Psathyromyia (Diptera:Phlebotominae) from a Biosphere Reserve of Veracruz,Mexico

Phlebotomine sand flies are considered the main vectors of Leishmania, the causal agents of leishmaniasis, which is a serious emerging public health problem worldwide. The use of biological control alternatives, like endosymbiotic bacteria (Wolbachia and Rickettsia), have been proposed to decrease sand fly populations and reduce Leishmania transmissions, yet only few records on the detection of Wolbachia or Rickettsia in sand flies are available worldwide. The aim of this study was to perform the molecular detection of Rickettsial agents associated with sand flies from the last patch of a rainforest in south-eastern Mexico, where a high prevalence of Leishmania infantum has been reported. Sampling effort of sand flies covered 300 trap-nights between 2011 and 2013, and a total of 925 specimens from twelve species were morphologically identified. Using PCR techniques, we identified a new lineage of the endosymbionts Rickettsia in Psathyromyia aclydifera (prevalence of 19.54%), and Wolbachia in Psathyromyia shannoni and Lutzomyia sp. (prevalence of 25%). The detected Wolbachia lineage was similar to the wWhi strain found in Pa. shannoni from Colombia and Nyssomyia whitmani from Brazil; whereas the identified Rickettsia represents a new lineage worldwide. This is the first record of Rickettsial agents associated to sand flies from this region, yet it remains for analysed if these bacteria possibly play a role as vector control agents, capable of reducing the sand fly populations in Mexico.     

Natural breeding places of phlebotomine sandflies

Methods of finding larvae and pupae of phlebotomine sandflies (Diptera: Psychodidae) are described and the known types of breeding sites used by sandflies are listed. Three ways of detecting sandfly breeding places are the use of emergence traps placed over potential sources to catch newly emerged adult sandflies; flotation of larvae and pupae from soil, etc., and desiccation of media to drive out the larvae. Even so, remarkably little information is available on the ecology of the developmental stages of sandflies, despite their importance as vectors of Leishmania, Bartonella and phleboviruses affecting humans and other vertebrates in warmers parts of the world. Regarding the proven or suspected vectors of leishmaniases, information on breeding sites is available for only 15 out of 29 species of sandflies involved in the Old World and 12 out of 44 species of sandflies involved in the Americas, representing approximately 3% of the known species of Phlebotominae. Ecotopes occupied by immature phlebotomines are usually organically rich moist soils, such as the rain forest floor (Lutzomyia intermedia, Lu. umbratilis, Lu. whitmani in the Amazon; Lu. gomezi, Lu. panamensis, Lu. trapidoi in Panama), or contaminated soil of animal shelters (Lu. longipalpis s.l. in South America, Phlebotomus argentipes in India; P. chinensis in China; P. ariasi, P. perfiliewi, P. perniciosus in Europe). Developmental stages of some species (P. langeroni and P. martini in Africa; P. papatasi in Eurasia; Lu. longipalpis s.l. in South America), have been found in a wide range of ecotopes, and many species of sandflies employ rodent burrows as breeding sites, although the importance of this niche is unclear. Larvae of some phlebotomines have been found in what appear to be specialized niches such as Lu. ovallesi on buttress roots of trees in Panama; P. celiae in termite hills in Kenya; P. longipes and P. pedifer in caves and among rocks in East Africa. Old World species found as immatures in the earthen floor of human habitations include P. argentipes, P. chinensis, P. martini and P. papatasi. Much more information on sandfly breeding sites is required to facilitate their control by source reduction.     

Detection and source identification of airborne extended-spectrum beta-lactamase-producing Escherichia coli isolates in a chicken house

To identify airborne dissemination of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) in a chicken house, airborne E. coli was collected from indoor air of a chicken house using six-stage Anderson sampler, and E. coli from chicken fecal samples were also isolated simultaneously. ESBL-producing E. coli isolates from indoor air and fecal samples were screened by a phenotypic confirmatory test according to CLSI recommendations. And then, the enterobacterial repetitive intergenic consensus polymerase chain reaction was performed to analyze the source of airborne ESBL-producing E. coli. The results showed that the ESBL-positive rates of E. coli isolates from feces and the indoor air were 56 % (18/32) and 40 % (6/15), respectively. Furthermore, airborne ESBL-producing E. coli isolates in the chicken house had 100 % genetic similarities with the strains from chicken feces, indicating that ESBL-producing E. coli from chicken feces could be aerosolized and spread to the air.     

Effects of Prebaiting on Small Mammal Trapping Success in a Morrow's Honeysuckle-Dominated Area

Abstract: Researchers have obtained mixed results in studies that use prebaiting to enhance small mammal trapping success. In 2004–2005 we tested the effects of prebaiting on small mammal trapping success in an exotic and invasive shrub community, Morrow's honeysuckle (Lonicera morrowii), using 4 80 × 120-m live trapping grids at Fort Necessity National Battlefield in Fayette County, Pennsylvania, USA. We randomly assigned traps to 1 of 3 trapping methods: we prebaited one-third of the traps 2 nights (n = 3,508 trap-nights), one-third one night (n = 3,492 trap-nights), and one-third had no prebaiting (n = 3,509 trap-nights). We compared small mammal richness, diversity, and relative abundance (no. captures/100 trap-nights) of white-footed mice (Peromyscus leucopus; n = 462 captures), meadow voles (Microtus pennsylvanicus; n = 89 captures), meadow jumping mice (Zapus hudsonius; n = 221 captures), masked shrews (Sorex cinereus; n = 87 captures), and shorttail shrews (Blarina brevicauda; n = 78 captures) among prebaited traps and non-prebaited traps. On the first day of trapping, as well as all 4 days combined, richness, diversity, and relative abundance for all species were similar among traps that we had prebaited for 2 nights, one night, and zero nights (P = 0.856). Moreover, total number of captures was similar among prebaiting treatments (P = 0.197). These results suggest that prebaiting does not enhance trapping success for small mammals in a landscape dominated by a dense, exotic shrub. We recommend that managers do not employ prebaiting in areas with similar small mammal species composition in an attempt to increase trapping success, as we did not record a difference in trapping success in prebaited traps compared to non-prebaited traps.     

Sediment Burial Intolerance of Marine Macroinvertebrates

The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura), the queen scallop (Aequipecten opercularis) and the sea squirt (Ciona intestinalis) were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris) and the anemone (Sagartiogeton laceratus), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa). With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps unsurprisingly, the greatest ability to emerge from burial in all other species was from shallow (2 cm) burial. Although survival was consistently highly dependent on duration and depth of burial as expected, emergence behaviour was not as easily predictable thereby confounding predictions. We conclude that responses to burial are highly species specific and therefore tolerance generalisations are likely to be oversimplifications. These data may be used to inform environmental impact models that allow forecasting of the cumulative impacts of seabed disturbance and may provide mitigation measures for the sustainable use of the seabed.     

Dispersal Range of Anopheles sinensis in Yongcheng City,China by Mark-Release-Recapture Methods

Background

Studying the dispersal range of Anopheles sinensis is of major importance for understanding the transition from malaria control to elimination. However, no data are available regarding the dispersal range of An. sinensis in China. The aim of the present study was to study the dispersal range of An. sinensis and provide the scientific basis for the development of effective control measures for malaria elimination in China.

Methodology/Principal Findings

Mark-Release-Recapture (MRR) experiments were conducted with 3000 adult wild An. sinensis in 2010 and 3000 newly emerged wild An. sinensis in 2011 in two villages of Yongcheng City in Henan Province. Marked An. sinensis were recaptured daily for ten successive days using light traps. The overall recapture rates were 0.83% (95% CI, 0.50%∼1.16%) in 2010 and 1.33% (95% CI, 0.92%∼1.74%) in 2011. There was no significant difference in the recapture rates of wild An. sinensis and newly emerged An. sinensis. The majority of An. sinensis were captured due east at study site I compared with most in the west at study site II. Eighty percent and 90% of the marked An. sinensis were recaptured within a radius of 100 m from the release point in study site I and II, respectively, with a maximum dispersal range of 400 m within the period of this study.

Conclusions/Significance

Our results indicate that local An. sinensis may have limited dispersal ranges. Therefore, control efforts should target breeding and resting sites in proximity of the villages.