Larval habitat characteristics of the main malaria vectors in the most endemic regions of Colombia: potential implications for larval control

Abstract Background Spatio-temporal trends in mosquito-borne diseases are driven by the locations and seasonality of larval habitat. One method of disease control is to decrease the mosquito population by modifying larval habitat, known as larval source management (LSM). In malaria control, LSM is currently considered impractical in rural areas due to perceived difficulties in identifying target areas. High resolution drone mapping is being considered as a practical solution to address this barrier. In this paper, the authors’ experiences of drone-led larval habitat identification in Malawi were used to assess the feasibility of this approach. Methods Drone mapping and larval surveys were conducted in Kasungu district, Malawi between 2018 and 2020. Water bodies and aquatic vegetation were identified in the imagery using manual methods and geographical object-based image analysis (GeoOBIA) and the performances of the classifications were compared. Further, observations were documented on the practical aspects of capturing drone imagery for informing malaria control including cost, time, computing, and skills requirements. Larval sampling sites were characterized by biotic factors visible in drone imagery and generalized linear mixed models were used to determine their association with larval presence. Results Imagery covering an area of 8.9 km2 across eight sites was captured. Larval habitat characteristics were successfully identified using GeoOBIA on images captured by a standard camera (median accuracy = 98%) with no notable improvement observed after incorporating data from a near-infrared sensor. This approach however required greater processing time and technical skills compared to manual identification. Larval samples captured from 326 sites confirmed that drone-captured characteristics, including aquatic vegetation presence and type, were significantly associated with larval presence. Conclusions This study demonstrates the potential for drone-acquired imagery to support mosquito larval habitat identification in rural, malaria-endemic areas, although technical challenges were identified which may hinder the scale up of this approach. Potential solutions have however been identified, including strengthening linkages with the flourishing drone industry in countries such as Malawi. Further consultations are therefore needed between experts in the fields of drones, image analysis and vector control are needed to develop more detailed guidance on how this technology can be most effectively exploited in malaria control.

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LARVAL HABITAT CHARACTERISTICS OF COQUILLETTIDIA PERTURBANS (DIPTERA: CULICIDAE) IN MINNESOTA

The Canadian Entomologist ◽

10.4039/ent1181193-11 ◽

1986 ◽

Vol 118 (11) ◽

pp. 1193-1198 ◽

Cited By ~ 9

Author(s):

Darold P. Batzer ◽

Robert D. Sjogren

Keyword(s):

Dissolved Oxygen ◽

Water Column ◽

Plant Species ◽

Aquatic Vegetation ◽

Larval Habitat ◽

Habitat Characteristics ◽

Breeding Sites ◽

Organic Debris ◽

Coquillettidia Perturbans ◽

Hennepin County

AbstractLarvae of Coquillettidia pertubans (Walker) are found in some marshes of permanent water with stands of aquatic vegetation. Eighty-six marshes, located within a 400-km2 area of Hennepin County, Minnesota, were examined in the fall of 1984 to determine factors that characterize C. perturbans breeding sites. We found that C. perturbans larvae attached to the roots of primarily Typha species although other plant species were also used. The water in sites with larvae was significantly deeper, lower in dissolved oxygen, and contained a significantly thicker layer of organic debris than sites without larvae. Larvae were associated with sites where Typha had specialized structures called water roots, which grow in the water column. Larvae inhabiting floating mats of vegetation were associated with interior openings within the mats.

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Species Composition and Diversity of Malaria Vector Breeding Habitats in Trincomalee District of Sri Lanka

BioMed Research International ◽

10.1155/2015/823810 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Nayana Gunathilaka ◽

Wimaladharma Abeyewickreme ◽

Menaka Hapugoda ◽

Rajitha Wickremasinghe

Keyword(s):

Sri Lanka ◽

Larval Habitat ◽

Malaria Vectors ◽

Entomological Surveillance ◽

Anopheles Subpictus ◽

Control Programs ◽

Breeding Habitats ◽

Elimination Programme ◽

Total Dissolved Solid ◽

The Relationship

Introduction. Mosquito larval ecology is important in determining larval densities and species assemblage. This in turn influences malaria transmission in an area. Therefore, understanding larval habitat ecology is important in designing malaria control programs.Method. Larval surveys were conducted in 20 localities under five sentinel sites (Padavisiripura, Gomarankadawala, Thoppur, Mollipothana, and Ichchallampaththu) in Trincomalee District, Eastern Province of Sri Lanka, between June 2010 and July 2013. The relationship between seven abiotic variables (temperature, pH, conductivity, Total Dissolved Solid (TDS), turbidity, Dissolved Oxygen (DO), and salinity) was measured.Results. A total of 21,347 anophelines were recorded representing 15 species.Anopheles subpictus24.72% (5,278/21,347) was the predominant species, followed by 24.67% (5,267/21,347) ofAn. nigerrimusand 14.56% (3,109/21,347) ofAn. peditaeniatus. A total of 9,430 breeding habitats under twenty-one categories were identified.An. culcicifacieswas noted to be highest from built wells (20.5%) with high salinity (1102.3 ± 81.8 mg/L), followed by waste water collections (20.2%) having low DO levels (2.85 ± 0.03 mg/L) and high TDS (1,654 ± 140 mg/L).Conclusion. This study opens an avenue to explore new breeding habitats of malaria vectors in the country and reemphasizes the requirement of conducting entomological surveillance to detect potential transmission of malaria in Sri Lanka under the current malaria elimination programme.

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Distribution and larval habitat characteristics of Anopheles Hyrcanus Group and related mosquito species (Diptera: Culicidae) in South Korea

Journal of Vector Ecology ◽

10.3376/1081-1710(2006)31[198:dalhco]2.0.co;2 ◽

2006 ◽

Vol 31 (1) ◽

pp. 198-205 ◽

Cited By ~ 24

Author(s):

Leopoldo M. Rueda ◽

Heung-Cheul Kim ◽

Terry A. Klein ◽

James E. Pecor ◽

Cong Li ◽

...

Keyword(s):

South Korea ◽

Mosquito Species ◽

Larval Habitat ◽

Habitat Characteristics

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Species composition and abundance of mosquito larvae in relation with their habitat characteristics in Mazandaran Province, northern Iran

Bulletin of Entomological Research ◽

10.1017/s0007485317000074 ◽

2017 ◽

Vol 107 (5) ◽

pp. 598-610 ◽

Cited By ~ 3

Author(s):

S.H. Nikookar ◽

M. Fazeli-Dinan ◽

S. Azari-Hamidian ◽

S.N. Mousavinasab ◽

M. Arabi ◽

...

Keyword(s):

Environmental Variables ◽

Larval Density ◽

Larval Habitat ◽

Habitat Characteristics ◽

Mosquito Larvae ◽

Mazandaran Province ◽

Natural Habitats ◽

Northern Iran ◽

Monthly Basis ◽

Larval Habitats

AbstractMosquitoes transmit a variety of diseases to humans. Their abundance and distribution are related to the characteristics of larval habitats. Mosquito larvae were collected from 120 natural and artificial habitats in 30 villages of 16 counties using standard 350 ml dippers and pipette, on a monthly basis from May–December 2014 in Mazandaran Province, northern Iran. Larval habitat characteristics were recorded separately, based on the conditions of the habitats (permanent or temporary, stagnant or running), type of habitats (natural or artificial), vegetation, exposure to sun, type of bed, water condition (clear or turbid), expanse (m), depth (cm, m) and temperature (°C) of habitats. The relationship between larval density and environmental variables was assessed by Chi-square tests. Totally, 19,840 larvae from three genera and 16 species were collected and identified.Anopheles maculipennis s.l.andCulex pipienswere the dominant species and collected with the highest density in plain areas. The highest number of larvae were collected from natural habitats (60.34%), including; river edge, marsh, pit and wetlands; with temporary and stagnant water, expanse of 0–5 m, depth of 1–25 cm, without plant, shadow-sun, muddy floor, turbid water, temperature 20–25°C and in sunny conditions. River edge and rice fields forAn. maculipennis s.land, wetlands and discarded tires forCx. pipienswere the main larval habitats in the province. Statistical analysis revealed significant relation between occurrence ofAn. maculipennis s.l., Cx. pipiens, Culex torrentium, Culex mimeticusandCs. annulatawith each of the environmental variables (P< 0.001). These findings are essential in expanding our knowledge of the vectors ecology specially the type of habitat preference and will be beneficial in larval control programs.

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Tests of conspecificity for closely related black fly (Diptera: Simuliidae) species of the Simulium striatum group in Thailand

Zootaxa ◽

10.11646/zootaxa.4231.3.8 ◽

2017 ◽

Vol 4231 (3) ◽

pp. 421 ◽

Cited By ~ 5

Author(s):

SIRINAPA PANGJANDA ◽

PAIROT PRAMUAL

Keyword(s):

Dna Sequences ◽

Developmental Stages ◽

Species Group ◽

Biological Species ◽

Larval Habitat ◽

Habitat Characteristics ◽

Elongation Complex ◽

Morphological Examination ◽

Black Fly ◽

Gill Filaments

Four black fly species of the Simulium striatum species group have been recorded in Thailand. These species are morphologically highly similar in all developmental stages except for the number and arrangement of the pupal gill filaments. In this study, we used multiple characters sources, including morphology, cytology, molecular biology and ecology, to test the hypothesis of conspecificity for S. quinquestriatum (Shiraki), S. nakhonense Takaoka & Suzuki and S. chiangmaiense Takaoka & Suzuki. A molecular study based on the cytochrome c oxidase subunit I (COI) was unable to separate these taxa. In contrast, the elongation complex protein 1 (ECP1) sequences clearly differentiate S. quinquestriatum from S. chiangmaiense and S. nakhonense. However, the latter two taxa could not be differentiated based on molecular DNA sequences. Simulium chiangmaiense and S. nakhonense are also similar in the larval habitat characteristics and have undifferentiated polytene chromosome banding patterns. Morphological examination of the number and arrangement of the pupal gill filaments found a number of intermediate forms. Therefore, S. chiangmaiense and S. nakhonense are apparently the same biological species that is polymorphic for the number and arrangement of gill filaments. Thus, we synonymized S. chiangmaiense with S. nakhonense.

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Bioecology of Dominant Malaria Vector, Anopheles superpictus s.l. Grassi (Diptera: Culicidae) In Iran

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v12i3.73 ◽

2018 ◽

Author(s):

Hassan Vatandoost ◽

Ahmad Ali Hanafi-Bojd ◽

Ahmad Raeisi ◽

Mohammad Reza Abai ◽

Fatemeh Nikpour

Keyword(s):

Public Health ◽

Public Health Problem ◽

Larval Habitat ◽

Malaria Vectors ◽

Related Factors ◽

Larval Habitats ◽

Sustainability Index ◽

Adult Females ◽

Flight Range ◽

Vector Borne

Background: Malaria continues to be a main vector-borne public health problem in Iran. The endemic foci of the disease are mainly located in south-eastern part of the country. Iran is now launching the elimination of malaria. Studies on the bioecology and susceptibility of malaria vectors to insecticide are essential in this phase. Methods: The literature on bio-ecology of Anopheles superpictus s.l. Grassi was reviewed in Iran in more than half a century. Different aspects including, distribution, key identification, larval habitats, flight range, seasonal activities, irritability/susceptibility to insecticides, and anthropophilicity index were identified. Results: The adult females of An. superpictus s.l. were susceptible to all WHO-recommended imagicides except DDT. Distribution, morphology, sibling species, larval habitat, flight range, Irritability tests, sustainability index, blood feeding preference and related factors were discussed in details Conclusion: Results of the evaluating will help for decision making of authorities for vector control.

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A cross-sectional observational study investigating the association between sedges (swamp grasses, Cyperaceae) and the prevalence of immature malaria vectors in aquatic habitats along the shore of Lake Victoria, western Kenya

F1000Research ◽

10.12688/f1000research.25673.2 ◽

2020 ◽

Vol 9 ◽

pp. 1032

Author(s):

Getachew E. Bokore ◽

Paul Ouma ◽

Patrick O. Onyango ◽

Tullu Bukhari ◽

Ulrike Fillinger

Keyword(s):

Cynodon Dactylon ◽

Lake Victoria ◽

Cyperus Rotundus ◽

Habitat Characteristics ◽

Malaria Vectors ◽

Aquatic Habitats ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Poaceae Family ◽

Early Instar

Background: Strategies that involve manipulations of the odour-orientation of gravid malaria vectors could lead to novel attract-and-kill interventions. Recent work has highlighted the potential involvement of graminoid plants in luring vectors to oviposition sites. This study aimed to analyse the association between water-indicating graminoid plants (Cyperaceae, sedges), other abiotic and biotic factors and the presence and abundance of early instar Anopheles larvae in aquatic habitats as a proxy indicator for oviposition. Methods: A cross-sectional survey of 110 aquatic habitats along the shores of Lake Victoria was done during the rainy season. Habitats were sampled for mosquito larvae using the sweep-net method and habitat characteristics recorded. Results: Anopheles arabiensis was the dominant species identified from aquatic habitats. Larvae of the secondary malaria vectors such as Anopheles coustani, An. rufipes and An. maculipalpis were found only in habitats covered with graminoids, whereas An. arabiensis, An. ziemanni and An. pharoensis were found in both habitats with and without graminoid plants. The hypothesis that sedges might be positively associated with the presence and abundance of early instar Anopheles larvae could not be confirmed. The dominant graminoid plants in the habitats were Panicum repens, Cynodon dactylon in the Poaceae family and Cyperus rotundus in the Cyperaceae family. All of these habitats supported abundant immature vector populations. The presence of early instar larvae was significantly and positively associated with swamp habitat types (OR=22, 95% CI=6-86, P<0.001) and abundance of late Anopheles larvae (OR=359, CI=33-3941, P<0.001), and negatively associated with the presence of tadpoles (OR=0.1, CI=0.0.01-0.5, P=0.008). Conclusions: Early instar malaria vectors were abundant in habitats densely vegetated with graminoid plants in the study area but no specific preference could be detected for any species or family. In search for oviposition cues, it might be useful to screen for chemical volatiles released from all dominant plant species.

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Larval habitat characteristics of mosquitoes of the genusCulisetaFelt, 1904 (Diptera: Culicidae) in the Caspian Sea littoral, Iran

Zoology in the Middle East ◽

10.1080/09397140.2005.10638128 ◽

2005 ◽

Vol 36 (1) ◽

pp. 59-66 ◽

Cited By ~ 5

Author(s):

Shahyad Azari-Hamidian

Keyword(s):

Caspian Sea ◽

Larval Habitat ◽

Habitat Characteristics ◽

The Caspian Sea

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Aedes albopictus Populations and Larval Habitat Characteristics across the Landscape: Significant Differences Exist between Urban and Rural Land Use Types

Insects ◽

10.3390/insects12030196 ◽

2021 ◽

Vol 12 (3) ◽

pp. 196

Author(s):

Katie M. Westby ◽

Solny A. Adalsteinsson ◽

Elizabeth G. Biro ◽

Alexis J. Beckermann ◽

Kim A. Medley

Keyword(s):

Land Use ◽

Aedes Albopictus ◽

Rural Areas ◽

Mosquito Species ◽

Larval Habitat ◽

Habitat Characteristics ◽

Water Evaporation ◽

Global Changes ◽

Local Conditions ◽

Land Use Types

One of the most profound recent global changes has been the proliferation of urban metropolitan areas. A consequence of urbanization is a reduction in abundance, or diversity, of wildlife. One exception, is the proliferation of vectors of disease; recent years have seen the emergence and resurgence of diseases vectored by species closely associated with humans. Aedes albopictus, a mosquito with a near global range and broad ecological niche, has been described as an urban, suburban, or rural vector, or a forest edge species depending on local conditions. We tested the hypothesis that abundance and phenological patterns of this species vary among different land use types in a temperate city because of the variation in the biotic and abiotic conditions characteristic of those habitat types. A. albopictus populations in urban and suburban areas were an order of magnitude larger than in rural areas and were detected several weeks earlier in the season. Additionally, we found fewer overall mosquito species, higher temperatures, lower nitrogen, higher pH, and faster water evaporation in larval habitats in urban vs. rural areas. By understanding the ecological differences that facilitate a species in one habitat and not another, we can potentially exploit those differences for targeted control.

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