Trap Nets Research Articles

Semi-field evaluation of human landing catches versus human double net trap for estimating human biting rate of Anopheles minimus and Anopheles harrisoni in Thailand.

BackgroundWhilst the human landing catch (HLC) technique is considered the ‘gold standard’ for estimating human-biting rates, it is labor-intensive and fraught with potential risk of exposure to infectious mosquito bites. This study evaluated the feasibility and performance of an alternative method, the human double net trap (HDNT) relative to HLC for monitoring host-seeking malaria vectors of the Anopheles minimus complex in a semi-field system (SFS).MethodsHDNT and HLC were positioned in two rooms, 30 m apart at both ends of the SFS. Two human volunteers were rotated between both traps and collected released mosquitoes (n = 100) from 6:00 pm till 6:00 am. Differences in Anopheles mosquito densities among the trapping methods were compared using a generalized linear model based on a negative binomial distribution.ResultsThere were 82.80% (2,136/2,580) of recaptures of wild-caught and 94.50% (2,835/3,000) of laboratory-reared mosquitoes that were molecularly identified as An. harrisoni and An. minimus, respectively. Mean density of An. harrisoni was significantly lower in HNDT (15.50 per night, 95% CI [12.48–18.52]) relative to HLC (25.32 per night (95% CI [22.28–28.36]), p < 0.001). Similarly, the mean density of a laboratory strain of An. minimus recaptured in HDNT was significantly lower (37.87 per night, 95% CI [34.62–41.11]) relative to HLC (56.40 per night, 95% CI [55.37–57.43]), p < 0.001. Relative sampling efficiency analysis showed that HLC was the more efficient trap in collecting the An. minimus complex in the SFS.ConclusionHDNT caught proportionately fewer An. minimus complex than HLC. HDNT was not sensitive nor significantly correlated with HLC, suggesting that it is not an alternative method to HLC.

Temporal Variation in Abundance and Distribution of Butterflies in a Southern Nigerian National Park

Aims: The aim of this study was to determine the butterfly diversity in Okomu National Park, Nigeria in order to make available information on butterfly species in this protected areas. Background: Butterflies are a taxonomically important group for predicting the health of the environment. Objective: In order to establish butterfly abundance and distribution in Okomu National Park, a temporal variation study was conducted for a period of twenty-four months (July 2012 to June 2014). Methods: Eight transects (Disturbed habitat (DIS), Forest Edge/Plantation (FE/P), Moderately Open Forest (MOF), Forest Along Road/Moist Patches (FAR/MP), Riparian Habitat (RIP), Closed Canopy (CC), Shrub (SHR) and Grassland (GRA) were mapped out from the four ranges (Igwonwan, Arakhuan, Julius Creek and Babui) from visual level of disturbance and degree of canopy closure for transect walk, butterfly net and baited trap methods of butterfly sampling. Environmental variables (temperature, relative humidity, and rainfall) were concurrently sampled with butterflies. Results: A total of 143 species and 6,310 individuals of butterflies were obtained from the families; Nymphalidae, Papilionidae, Pieridae, Lycaenidae, and Hesperiidae. Nymphalid (3103: 49.2%) and Pieridae (2269: 36.0%) predominated and Hesperiidae was recorded low (8: 0.1%). Significant differences were observed in the abundance of butterflies in the transects (p&lt; 0.05). Rainfall was positively correlated with butterfly abundance. Butterfly abundance was higher in rainy season compared to dry season except in RIP where a reverse trend was observed. Abundance was higher in FAR/MP (1633: 25.9%) and MOF (1251: 19.8%) compared to other transects, and was lowest in SHR (295: 4.7%). Conclusion: It can be concluded that butterfly in Okomu forest is abundant and stable, and as such continuous effort is required to conserve butterfly flora and fauna in this park.

Host preference of bluetongue virus vectors, Culicoides species associated with livestock in West Bengal, India: Potential relevance on bluetongue epidemiology

Determination of host choice of Culicoides species (Diptera: Ceratopogonidae), the vectors of bluetongue virus (BTV), is pivotal to ascertain the role of each species in the transmission of pathogens, pest management and enumeration of disease prediction models. Host preference of livestock associated Culicoides midges was investigated in West Bengal, India with four replicates of a 3 × 3 Latin square design during August and September 2021. Adult Culicoides were mouth aspirated from three BTV hosts viz., cattle, sheep and goats. Mouth aspirating was validated by the sweep net collections. The host-baited collections recorded seven Culicoides species; with the highest landing rate on cattle (n = 5,667; 92.9%) followed by sheep (n = 365; 6.0%) and goat (n = 67; 1.1%). Based on the Jacob's selectivity index, all midge species, except for Culicoides fulvus Sen & Das Gupta, encountered, preferred cattle over other mammalian hosts. Culicoides oxystoma Kieffer, the subgenus Trithecoides Wirth & Hubert and Culicoides actoni Smith, predominated on the ventral region (belly/flank) of the cattle. However, Culicoides peregrinus Kieffer and C. actoni were observed to be prevalent in the leg region of sheep. A significantly higher percentage of female (99.9%) with only 0.3% of male were trapped in aspiration based animal baited collections. On the other hand sweep net and light trap catch comprises of 50.7%, 89.7% female and 49.2%, 10.2% male respectively. Surprisingly, DNA based blood meal analysis revealed human blood from the midges trapped in UV-LED light traps. Supplying the first evidence that Culicoides similis Carter, Ingram & Macfie, C. fulvus and Culicoides palpifer Das Gupta & Ghosh, feed on humans.

Influence of fishing gears used by fisherfolks on fish yield in River Benue, Nigeria

This study was carried out to ascertain the influence of fishing gear used by fisherfolks on the yield of fish in River Benue, Nigeria. The study was conducted in three fishing villages that are also landing sites. They are within Adamawa State axis with the Benue River passing through them. The selected villages are Boranji (Site 1), Damare (Site 2) and Hayin gada (Site 3). The study was conducted bi-monthly for three months from the month of July to September 2021. In the conduct of this study, both primary and secondary methods of data collection were used. A total of One Hundredand Forty (140) respondents were sampled with structured interview and questionnaire. The study showed that the fishing gears employed and operated in the study sites are used to capture different species of fish. Most prominent of the gearsu is the gill net and Malian trap. The study also revealed that Sixteen (16) fish species from seven (7) families were caught by the six artisanal fishing gears in all the sites. The study revealed the obvious neglect of the artisanal fisherfolks with regards to provision of infrastructural facilities despite the enormous contribution they give to the domestic fish output.

Identification of Blood-sucking Flies of Bats in Lombok Island, Indonesia

Bats and blood-sucking bat flies have an important role in transmitting several hemoparasites. Bat flies have been identified as vectors transmitting hemoparasites from wild bats. The purpose of the present study was to identify bats and their blood-sucking flies as vectors of hemoparasites in bat caves located at Lombok Island, Indonesia. In the course of the study, a survey was conducted on three bat caves from September to December 2018. The bats were captured by a net trap and the species of bats and bat flies were identified. A total of 66 captured bats were identified as Hipposideros species (n = 28), Eonycteris spelaea (n = 23), and Taphozouss species (n = 15). The blood-sucking flies were identified as Eucampsipoda sundaica on Eonycteris spelaea, and Stylidia cf. euxesta, Brachytarsina species, Raymondia species, and Megastrebla nigriceps on Hipposideros species. The results showed that five species of blood-sucking flies were present in captured bats. The bat and blood-sucking flies can influence the transmission of Polychromophilus species, Babesia species, Plasmodium species, and Trypanosoma species to humans and other hosts.

Outdoor biting and pyrethroid resistance as potential drivers of persistent malaria transmission in Zanzibar

BackgroundLow-level of malaria transmission persist in Zanzibar despite high coverage of core vector control interventions. This study was carried out in hot-spot sites to better understand entomological factors that may contribute to residual malaria transmission in Zanzibar.MethodsA total of 135 households were randomly selected from six sites and consented to participate with 20–25 households per site. Mosquito vector surveillance was carried out indoors and outdoors from 6:00 pm–7:00 am using miniaturized double net trap (DN-Mini™). Additional collections were done indoors using mouth aspirators to retrieve resting mosquitoes from wall and ceiling surfaces, and outdoors using resting bucket and pit traps. All collected mosquitoes were morphologically and genetically (PCR) analysed in the laboratory. All collected anopheline and blood-fed mosquitoes were analysed for sporozoite infection and blood meal host preferences by Circumsporozoite Protein ELISA and blood meal ELISA, respectively. The differences between indoor and outdoor mosquito biting rates were analysed using generalized linear mixed models. Levels of resistance to commonly used insecticides were quantified by WHO susceptibility tests.ResultsOut of 704 malaria vectors collected across 135 households, PCR analysis shows that 98.60% were Anopheles arabiensis, 0.6% Anopheles merus and 0.6% Anopheles gambiae sensu stricto. Sporozoite ELISA analysis indicates that all mosquitoes were negative for the malaria parasite. The results show that more An. arabiensis were collected outdoor (~ 85%) compared to indoor (~ 15%). Furthermore, large numbers of An. arabiensis were caught in outdoor resting sites, where the pit trap (67.2%) collected more mosquitoes compared to the outdoor DN-Mini trap (32.8%). Nearly two-thirds (60.7%) of blood-fed mosquitoes had obtained blood meals from non-human hosts. Mosquitoes displayed non-uniform susceptibility status and resistance intensity among the tested insecticides across the study sites to all WHO recommended insecticides across the study sites.ConclusionThis study suggests that in contexts such as Zanzibar, testing of novel techniques to complement indoor protection and targeting outdoor biting and/or resting mosquitoes, may be warranted to complement existing interventions and contribute to malaria elimination efforts. The study highlights the need to implement novel interventions and/or adaptations of strategies that can target outdoors biting mosquitoes.

Inventarisasi Serangga Pada Pertanaman Jeruk Nipis (Citrus Aurantifali) di Desa Plosogenuk Kecamatan Perak Kabupaten Jombang

This research was conducted at September – November 2020 with the aim of knowing the types of pests and diseases that predominantly attack lime in Perak District, Jombang Regency. This research is descriptive quantitative, namely direct sampling from the observation location, using traps such as trap holes, trap nets and direct observations on lime plantations. Sampling of all plants will be the sampling point (30 plants. Observations were made 10 repetitions, with an observation time interval of 3 days. The pest data obtained were identified and analyzed using the abundance index (K) and Dominant index (C) formulas. The pest identification study obtained 504 individuals consisting of 6 species. The highest insect abundance (K) value was found in the Coccidae family with the Order Homoptera, which was 53,968. The dominance index value was 0.29 indicating the result that there was no dominant family in this study planting.

Climate Variability Shifting Immigrated Rice Planthoppers in Taiwan

Rice planthoppers are common insect pests in Taiwan, and they have caused significant damage in the past. The majority of rice planthoppers have seen a drastic decline in their population since the mid-2000s, a trend that has anecdotally attributed to widespread and better pest control, as well as improved rice cultivation management. By analyzing 40 years of the airborne net trap data of rice planthoppers collected in Southwest Taiwan, it was found that the pests’ yearly population, computed with a logarithmic transformation, resembles a signature climate pattern in the global oceans with a robust multi-decadal variability. An ocean temperature-based index derived from the patterns of multi-decadal variability shows a marked resemblance with the population change of common rice planthoppers, with overlapping peaks during the 1990–2010 period. The climate dynamics associated with the regional weather pattern in the vicinity of Taiwan are discussed. Phase reversal of this multi-decadal climate variability in the future may produce favorable climatic conditions for the rice planthopper population to increase back to its historical levels.

Behavioral responses of pyrethroid resistant and susceptible Anopheles gambiae mosquitoes to insecticide treated bed net.

Long-lasting insecticidal nets are an effective tool in reducing malaria transmission. However, with increasing insecticide resistance little is known about how physiologically resistant malaria vectors behave around a human-occupied bed net, despite their importance in malaria transmission. We used the Mbita bednet trap to assess the host-seeking behavior of insecticide-resistant Anopheles gambiae mosquitoes under semi-field conditions. The trap incorporates a mosquito netting panel which acts as a mechanical barrier that prevents host-seeking mosquitoes from reaching the human host baiting the trap. Susceptible and pyrethroid-resistant colonies of female Anopheles gambiae mosquitoes aged 3-5 days old were used in this study. The laboratory-bred mosquitoes were color-marked with fluorescent powders and released inside a semi-field environment where a human subject slept inside a bednet trap erected in a traditional African hut. The netting panel inside the trap was either untreated (control) or deltamethrin-impregnated. The mosquitoes were released outside the hut. Only female mosquitoes were used. A window exit trap was installed on the hut to catch mosquitoes exiting the hut. A prokopack aspirator was used to collect indoor and outdoor resting mosquitoes. In addition, clay pots were placed outside the hut to collect outdoor resting mosquitoes. The F1 progeny of wild-caught mosquitoes were also used in these experiments. The mean number of resistant mosquitoes trapped in the deltamethrin-impregnated bed net trap was higher (mean = 50.21± 3.7) compared to susceptible counterparts (mean + 22.4 ± 1.31) (OR = 1.445; P<0.001). More susceptible mosquitoes were trapped in an untreated (mean = 51.9 ± 3.6) compared to a deltamethrin-treated bed net trap (mean = 22.4 ± 1.3) (OR = 2.65; P<0.001). Resistant mosquitoes were less likely to exit the house when a treated bed net was present compared to the susceptible mosquitoes. The number of susceptible mosquitoes caught resting outdoors (mean + 28.6 ± 2.22) when a treated bed net was hanged was higher than when untreated bednet was present inside the hut (mean = 4.6 ± 0.74). The susceptible females were 2.3 times more likely to stay outdoors away from the treated bed net (OR = 2.25; 95% CI = [1.7-2.9]; P<0.001). The results show that deltamethrin-treatment of netting panels inside the bednet trap did not alter the host-seeking behavior of insecticide-resistant female An. gambiae mosquitoes. On the contrary, susceptible females exited the hut and remained outdoors when a treated net was used. However, further investigations of the behavior of resistant mosquitoes under natural conditions should be undertaken to confirm these observations and improve the current intervention which are threatened by insecticide resistance and altered vector behavior.

Length weight relationships of fish species collected after impoundment of the Three Gorges Reservoir (TGR) in China; a study carried out in the upper Yangtze River

The Three Gorges Dam in the upper Yangtze River in China is the largest hydropower project in the world. Length- weight relationships (LWRs) are reported for fish species collected from three locations of the reservoir from November 2010 to October 2011. Fish were collected from the local fishing boats using 1.5 cm nylon mesh trap nets or 4, 5 and 6 cm nylon mesh gillnets (100- 120 m long × 1.4-1.5 m high). A total of 7,311 fish representing 49 species of 11 families were collected during the study period. There were 2,680 fish belonging to 32 species of 8 families sampled in Zigui (near the dam) reach, 2,845 fish representing 46 species of 8 families in Wanzhou (middle of the reservoir) reach and 1,786 fishes representing 38 species of 8 families in Fuling (upper reservoir) reach. The family with the highest number of species was Xenocyprididae. The intercept (a) and slope (b) of LWRs are useful in fisheries science in many ways. Therefore, the present study provides baseline data on LWRs of the economically valuable and most abundant fish species in the recently commissioned Three Gorges Reservoir.

Factors Related to Crappie Indices of Abundance in a Large, Fluctuating Canyon Reservoir in Idaho

Crappie (Pomoxis spp.) populations are challenging to manage due to highly variable year-class strength; however, such variability has rarely been investigated in western North America, where crappie often occupy large, steep-sided reservoirs prone to severe drawdown. We investigated the influence that various factors had on crappie abundance, as indexed by long-term trawling for larval fish and long-term electrofishing for older fish. Our primary findings were that: 1) autumn age-0 crappie abundance was higher in years when larval abundance and reservoir flow were higher in the summer; 2) spring age-1 crappie abundance was higher in years when fish were larger and more abundant entering their first winter, when hydraulic residence time was reduced and the reservoir volume was higher during the winter, and when predatory-sized smallmouth bass (Micropterus dolomieu) were more abundant in the spring (though the latter relationship was likely not causative but rather a parallel response to mutually advantageous environmental conditions in the reservoir); and 3) age-0 crappie entering their first winter were larger in years with lower summer larval crappie abundance and warmer summer water temperature. We recommend autumn electrofishing to monitor crappie populations in large canyon reservoirs, where shorelines are often too steep to sample fish with trap nets, because it provides an index of age-0 crappie abundance and size at the onset of their first winter as well as data on older crappie year classes and sympatric species; it also requires less sampling effort than summer trawling.

The social-ecological dynamic of small-scale fisheries in Coastal Area of Dumai City

Small-scale fishery activities that often occur in coastal areas Dumai City are part of the socio-ecological system, where the waters around the coastal areas provide services to several fishermen who live around and are interrelated with each other. This study aimed to identify the dynamic of social and ecological systems to the sustainability of small-scale fisheries in the waters of Dumai City. The are 3 research location in village, namely Pelintung, Tanjung Palas, and Bangsal Aceh. The research method is a survey using interview techniques with a questionnaire. The data analysis in this research is descriptive qualitative, fishing gear productivity, fishermen’s income, and the relationship dynamics of the catch. The social characteristics of fishermen can be shown from their education, where most of the fishermen in Dumai City have elementary school education. The wives of fishers in Dumai City are mostly still taking care of the household, and only a few are processing fish. Fishers in Dumai City also carry out the duration of fishing operations based on the type of fishing gear (gillnet, scoop net, and portable trap). For the last seven years, the productivity of fishing with gillnet fishing gear has increased, while for scoop net and portable trap fishing gear, it has tended to decrease. The RPUE value of gillnet fishers shows the highest profit, where the average income in one trip is IDR 1,086,050.00 compared to other fishers. The fishermen’s perception also shows that the catch of gillnet fishers during the last five years has increased.

Biodiversity And Arthropod Abundance In Organic Semi Rice In Swamp Lowland in Palangka Raya City

Palangka Raya has the potential for swamp lowland to be used for rice farming. For this purpose, knowledge of arthropod biodiversity is required. The study aims to determine the biodiversity and abundance of arthropods and arthropods dominant in semi-organic rice plantations in swamp lowlands. The study was conducted from September to November 2019 in Palangka Raya City. The study was carried out on 1.148m2 farmer's paddy fields. The land is divided into three trial plots, each measuring 28x13 m2. Observations were made at the age of 8-15 WAP. Samples were taken using a net trap (Sweep net). Arthropod biodiversity was analyzed using the Shannon-Weaver diversity index (H'). The results showed that in the semi-organic rice ecosystem were obtained 10 orders, 58 families with a total of 8973 individuals, consisting of pests 92.61%, predators 6.59%, parasitoids 0.28%, pollinators 0.06%, Detrivore 0.35%, and 0.07% neutral insects. Diversity index (H') is low to moderate (0.10-2.19), dominance index (C) is in the low to high (0.18-0.97); Evenness index shows that the community is depressed until unstable (0.04-0.67); and The abundance index on the criteria of less to very much (8.96-25.03). The dominant arthropods are dominated by the Rice bug (Leptocorisa acuta).

Net Traps – Reasons for Completing the Definition of Media Literacy

The paper aims to present the characteristics of the net given through the prism of supporters and skeptics. That range reveals net traps at social platforms through the crisis of democracy as an introduction to netocracy, and at the individual platform. A particular problem that arises from this is the definitions of media literacy that are focused on life in the media. The paper presents completing the definition of media literacy with the term „exclusion“, which leads to life with media.

Anopheline Diversity in Indonesia: An Evaluation of Animal-Baited Sampling Techniques.

Indonesia has rich Anopheline (Diptera: Culicidae) mosquito species living in various types of ecosystems. The study was conducted to profile and compare Anopheles diversity, equitability, and dominance in various ecosystems using different animal-based sampling techniques. The present study analyzed a subset of data collected from a nation-wide vector and animal reservoirs survey in 2016. Analyses were restricted to three ecosystem types (forest, nonforest, and coastal areas) in Java and Sumatera Islands. A total of 5,477 Anopheles were collected by using animal-baited (n = 1,909) and animal-baited trap nets (n = 1,978), consisting of 23 Anopheline species. Overall, Anopheles vagus was the most abundant species, followed by An. subpictus and An. barbirostris. Among the three ecosystems, the forest had a higher diversity index (H' = 1.98), but each ecosystem has its specific predominant species. Compared with the animal-baited method, the Anopheles abundance collected by animal-baited trap nets was two-fold higher. Ecosystem, elevation, and sampling methods were associated with the abundance of female Anopheles (P-value < 0.001). Our findings revealed that Anopheles were found in a different ecosystem, indicating the potential of malaria transmission. This suggests that improved malaria vector surveillance is essential in all types of ecosystem. Furthermore, the study suggested that animal-baited trap nets could be used as the standard method of outdoor resting sampling in Indonesia in addition to the traditional human landing collection approach.

Diversity of fishery resources and catch efficiency of fishing gears in Gorai River, Bangladesh

Gorai River is one of the important rivers in Bangladesh for rich aquatic biodiversity. The river is originated from the Ganges-Padma River system, a trans-boundary river between India and Bangladesh. Once the river was rich in fish biodiversity, but due to man-made and natural causes the availability of fish reduced drastically. A comprehensive analysis of fish diversity indices, gear efficiency, catch composition and decline causes of fish diversity in Gorai River, Bangladesh was accomplished. The data were collected on monthly basis from January to December 2018 from three major fishing sites of the river. A total of 62 fish and 2 prawn species under 12 orders and 24 families were recorded. Cypriniformes was the leading order consisting 27% of the total catch. The mean values of Shannon-Weaver diversity (H′), Simpson's index (1-D), Margalef's richness (d) and Pielou's evenness (J′) indices were recorded as, 1.478 ± 0.495, 0.57 ± 0.197, 15.115 ± 4.435 and 0.481 ± 0.152, respectively. At the similarity of 58.7%, two groups were attained in the cluster analysis and the Non-metric Multidimensional Scaling (nMDS) showed 40% similarity among the three sites in twelve months based on the Bray-Curtis similarity matrix. The highest and lowest CPUE were recorded from seine net (5.2 ± 1.72 kg gear−1 haul−1) and hook & long lines (0.0135 ± 0.0015 kg gear−1haul−1), respectively whereas, highest and lowest gear efficiency were recorded from lift net (0.321 ± 0.036 kg gear−1person−1hour−1) and fish trap (0.0005 ± 0.0002 kg gear−1person−1hour−1), respectively. Alternatively, the highest fish catch was recorded on April (21228 ± 464.38 kg) and lowest on August (3855 ± 138.21 kg). According to the fishermen fish biodiversity of the Gorai River declined day by day due to overexploitation, destructive fishing practice, pollution, construction of obstacles for fish movement, and natural causes like siltation. Proper implementation of fish acts and regulations, use of authorized fishing gear, community-based fisheries management, sanctuary establishment and management, stocking of fish fingerling, and raising public awareness can play a great role in enhancing and conserving fish biodiversity in the Gorai River of Bangladesh.

Impact of meteorological parameters on mosquito population abundance and distribution in a former malaria endemic area, central Iran

Meteorological parameters, have been identified as an important factor involved in the transmission of vector-borne diseases. Mosquitoes are extremely sensitive to weather conditions. The aim of this study was investigate the correlation between meteorological parameters and the abundance of mosquitoes in Kashan County. Mosquitoes were collected using four different traps, including hand catch, animal baited bed net trap (usually a cow), human baited bed net trap and BG-Sentinel trap with CO2 from May to December 2019. A total number of mosquitoes collected were 1756 out of which 1621 (92.31%) were Culex, 22 (1.25%) Culiseta and 113 (6.44%) Anopheles in nine species. Most mosquitoes were collected by BG-Sentinel trap with CO2 (63.78%). Monthly distribution of the mosquitoes indicated different monthly peaks. Their high density were recorded in September and were low in December. The spearman's correlation of the mosquito abundance and the meteorological parameters shows that correlation of the number of total collected mosquitoes with relative humidity and precipitation (Rainfall) was weak negative, and there was week correlation with wind speed, and positive strong correlation with temperature. Data collected with various trap types and mosquito correlation with meteorological parameters in this study can be used for mosquito surveillance and control programs. However, meteorological parameters affect the abundance of mosquitoes, but their impact is complex and most of these variables are species specific.

Production of Rhizophora Mangrove Leaf Litter in The Sungai Bersejarah Mangrove Ecosystem, Siak Regency

The mangrove ecosystem is one of the coastal ecosystems that has important ecological roles and functions in supporting marine and fishery resources. Marine and fisheries resources are largely determined by the contribution of mangrove litter. The aims of this study was to determine the production of Rhizophora mangrove leaf litter in Sungai Bersejarah mangrove ecosystem, and to determine the value of environmental parameters related to litter. The research was conducted in January until March 2021 in Sungai Bersejarah mangrove area Kayu Ara Permai, Siak Regency. Line transect plot were used to calculate the density of Rhizophora. Rhizophora litter production was measured using the trap net method placed at three sampling site. Three litter trap nets measuring 1 m x 1 m are placed at each station. Rhizophora tree density ranges from 316 - 444 ind./ha. The production of Rhizophora mangrove leaf litter in Sungai Bersejarah mangrove ecosystem was 0.82 – 1.39 g/m2/day (3.00 – 5.09 ton/ha/year), average was 4.11 ton/ha/year. Analysis of variance test showed that there was a significant difference in Rhizophora leaf litter production between sampling points with different Rhizophora tree densities (p<0.05). Mangrove vegetation density has a moderate relationship (r=0.43) to the production of Rhizophora mangrove leaf litter. Environmental parameters indicate that the condition of the Sungai Bersejarah mangrove ecosystem is still good and can support the life of mangrove vegetation.

Species Variety of the Calf and Human-Attracted Mosquitoes in Southwest Iran.

Background:Any mosquito control methods requires precise information about population dynamics, variety, biology and mosquito habitat. This research assessed Culicid mosquitoes’ attraction to a human host and a calf to better understand their behavior.Methods:Adult mosquitoes were sampled in 22 weeks in southwestern Iran’s Nur Ali Village from May to October 2015. The mosquitoes were drawn to the person and calf as bait, while the unbaited trap was also used. A substantial statistical difference between attracted mosquitoes to the hosts was determined in the T-test.Results:Within 22 weeks, 29821 mosquitoes were captured. Only 9% were collected from the human baited net trap, 89.1% from the calf baited net trap, and 1.9% from the unbaited net trap. The number of collected female mosquitoes was statistically significantly higher using the calf baited net trap of the total mosquitoes, 916 were randomly identified at the species level by local identification keys. Of these, 63 were Anopheles stephensi (human: 16%, calf: 75% and unbaited: 9%), 83 An. pulcherrimus (human: 27%, calf: 60% and unbaited: 13%), 118 Aedes caspius (human: 24%, calf: 69% and unbaited: 7%), 493 Culex tritaeniorhynchus (human: 52%, calf: 37% and unbaited: 11%), 153 Cx. quinquefasciatus (human: 44%, calf: 47% and unbaited: 9%), and 6 Cx. theileri (human: 33%, calf: 50% and unbaited: 17%).Conclusion:The obtained results here provide useful insights into the mosquito population and the possibility of using this information as an essential part of integrated vector management regarding the reemergence of malaria or other mosquito-borne.

Entomological survey in two communes with residual malaria transmission in Gia Lai Province in the central highlands of Vietnam

BackgroundIn 2018, the National Malaria Control Programme in Vietnam switched from prioritizing malaria control to elimination. However, with the ongoing elimination programme, there are still areas where residual malaria transmission persists, including the central highlands. This entomological survey was conducted to evaluate Anopheles diversity and host-seeking activity of Anopheles vectors in two communes with very low malaria transmission in Gia Lai Province.MethodsAnopheles species were collected in Ia DReh commune and Ia KDam commune, Gia Lai Province in the central highlands of Vietnam. Collections were conducted using human-baited double net trap, light trap and manual aspiration collections around cattle sheds, in the dry and rainy season. Mosquito specimens were identified morphologically, and members of species complexes were distinguished molecularly. Mosquito night-feeding patterns were investigated during the dry and rainy seasons.ResultsOverall, 18,835 specimens including 19 taxa were collected in Ia KDam and Ia DReh communes. These included the primary malaria vectors, Anopheles dirus and Anopheles minimus, and other secondary vector species. Anopheles dirus was observed to be an anthropophilic species, whereas An. minimus and a number of secondary vectors were observed to be zoophilic. Anopheles vagus was the dominant species, followed by Anopheles sinensis and Anopheles peditaeniatus. The majority of specimens were collected in the rainy season due to the relatively large number of An. vagus, while An. peditaeniatus, An. dirus, Anopheles kochi, Anopheles monstrosus and Anopheles tessellatus were collected in greater numbers during the dry season. The peak of host-seeking activity for An. dirus, An. sinensis, and An. vagus was between 18.00 and 19.00 h.ConclusionThis study provided information on the diversity, seasonal prevalence and behaviour of Anopheles at the study sites. Identifying the diverse mosquito fauna in the central highlands of Vietnam allows species-specific control measures to be implemented by the National Programme to reduce malaria in areas of very low malaria transmission. The peak Anopheles host-seeking activity observed in this study was between 18.00 and 23.00 h, which highlights the need to better characterize Anopheles behaviour in this region of Vietnam to inform on vector control strategies.