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1.
J Insect Sci ; 21(2)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33861349

RESUMO

We describe the development, field testing, and results from an automated 3D insect flight detection and tracking system for honey bees (Apis mellifera L.) (Hymenoptera: Apidae) that is capable of providing remarkable insights into airborne behavior. It comprises two orthogonally mounted video cameras with an observing volume of over 200 m3 and an offline analysis software system that outputs 3D space trajectories and inflight statistics of the target honey bees. The imaging devices require no human intervention once set up and are waterproof, providing high resolution and framerate videos. The software module uses several forms of modern image processing techniques with GPU-enabled acceleration to remove both stationary and moving artifact while preserving flight track information. The analysis system has thus far provided information not only on flight statistics (such as speeds and accelerations), but also on subtleties associated with flight behavior by generating heat maps of density and classifying flight patterns according to patrol and foraging behavior. Although the results presented here focus on behavior in the locale of a beehive, the system could be adapted to study a wide range of airborne insect activity.


Assuntos
Abelhas/fisiologia , Entomologia/métodos , Etologia/métodos , Voo Animal , Animais
2.
Sensors (Basel) ; 21(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672508

RESUMO

Drastic declines in insect populations are a vital concern worldwide. Despite widespread insect monitoring, the significant gaps in the literature must be addressed. Future monitoring techniques must be systematic and global. Advanced technologies and computer solutions are needed. We provide here a review of relevant works to show the high potential for solving the aforementioned problems. Major historical and modern methods of insect monitoring are considered. All major radar solutions are carefully reviewed. Insect monitoring with radar is a well established technique, but it is still a fast-growing topic. The paper provides an updated classification of insect radar sets. Three main groups of insect radar solutions are distinguished: scanning, vertical-looking, and harmonic. Pulsed radar sets are utilized for all three groups, while frequency-modulated continuous-wave (FMCW) systems are applied only for vertical-looking and harmonic insect radar solutions. This work proves the high potential of radar entomology based on the growing research interest, along with the emerging novel setups, compact devices, and data processing approaches. The review exposes promising insect monitoring solutions using compact radar instruments. The proposed compact and resource-effective setups can be very beneficial for systematic insect monitoring.


Assuntos
Entomologia/métodos , Insetos , Radar , Animais , Entomologia/instrumentação
3.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33480429

RESUMO

The interest in using byproducts from agro-food industries as a rearing substrate for insects is increasing rapidly. We investigated the influence of byproducts of vegetal origin (okara-a byproduct of soy milk production, maize distillers with solubles, brewer's grains), used as rearing diet for black soldier fly larvae (BSFL), on the following parameters: biomass production, substrate reduction (SR), nutritional profile and in vitro digestibility, and larval gut microbiota. Hen diet was used as a control substrate. The highest larval biomass was collected on maize distillers, whereas the highest SR was observed on okara. The rearing substrate affected ash, ether extract, and chitin larval content. The BSFL reared on okara were characterized by a lower lauric acid content (17.6% of total fatty acids). Diets also influenced in vitro crude protein digestibility (%) for monogastrics, with the highest values for BSFL reared on maize distillers (87.8), intermediate for brewer's grains and okara BSFL, and the lowest for hen BSFL (82.7). The nutritive value for ruminants showed a lower Net Energy for lactation for BSFL reared on hen diet than okara and dried maize distillers BSFL. The different byproducts showed an influence on the larval gut microbiota, with a major bacterial complexity observed on larvae fed with the hen diet. The neutral detergent fiber concentration of dietary substrate was negatively correlated with Firmicutes and Actinobacteria relative abundance. Insects valorized byproducts converting them into high-value larval biomass to be used for feed production. The results evidenced the effects of the tested byproducts on the measured parameters, underling the chemical composition importance on the final insect meal quality.


Assuntos
Ração Animal/análise , Digestão , Dípteros/fisiologia , Metabolismo Energético , Entomologia/métodos , Controle de Insetos/métodos , Agricultura , Animais , Biomassa , Dieta , Dípteros/crescimento & desenvolvimento , Dípteros/microbiologia , Resíduos Industriais/análise , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Microbiota
4.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33428743

RESUMO

To properly define ecoregions, specific criteria such as geology, climate, or species composition (e.g., the presence of endemic species) must be taken into account to understand distribution patterns and resolve ecological biogeography questions. Since the studies on insects in Baja California are scarce, and no fine-scale ecoregions based on the region's entomofauna is available, this study was designed to test whether the ecoregions based on vegetation can be used for insects, such as Calliphoridae. Nine collecting sites distributed along five ecoregions were selected, between latitudes 29.6° and 32.0°N. In each site, three baited traps were used to collect blow flies from August 2017 to June 2019 during summer, winter, and spring. A total of 30,307 individuals of blow flies distributed in six genera and 13 species were collected. The most abundant species were Cochliomyia macellaria (Fabricius), Phormia regina (Meigen), and Chrysomya rufifacies (Macquart). The composition of the Calliphoridae community was different between the localities and three general groups have been distinguished, based on the species composition similarity (ANOSIM) results: Gulf-Desert, Mountains, and Pacific-Center. The vegetation-based ecoregions only reflect the blow fly species' distributions to a certain extent, meaning that care must be taken when undertaking ecological biogeographical studies using regionalization based on organisms other than the focal taxa because vegetation does not always reflect fauna species composition.


Assuntos
Biodiversidade , Ecossistema , Entomologia/métodos , Ciências Forenses/métodos , Animais , México , Estações do Ano
5.
J Insect Sci ; 20(3)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32593171

RESUMO

Large-scale insect rearing for food and feed production can be improved by understanding diet digestion and host-microbe interactions. To examine these processes in black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) larvae, two protocols were developed. Protocol 1 describes a method to produce viable, sterile black soldier fly larvae and a gentle method for diet sterilization. Sterile black soldier fly larvae can be used to study the diverse role of microbes in larval development. Nutrient requirements of sterile black soldier fly larvae are met only through diet. Viable sterile black soldier fly larvae were consistently generated using a four-step treatment with alternating immersions of eggs for 2 min each in ethanol (70%) and sodium hypochlorite (0.6%), over two cycles. A nonthermal method of diet sterilization, namely high-energy electron beam (HEEB) treatment, was introduced. Subsequently, growth of sterile black soldier fly larvae was observed on the HEEB-treated diets (40, 60, and 40% of replicates with poultry feed, liver pie, and an artificial diet, respectively) but not on autoclaved diets. In Protocol 2, we propose a novel method to collect frass from individual larvae. We then measured the metabolites in frass, using high-pressure liquid chromatography. Results on metabolites confirmed the influence of digestion. For instance, succinate increased from 1 to 2 and 7 µmol/g sample from diet to gut homogenate and frass, respectively. The collection method is a promising tool to estimate the diet and nutrient requirements of black soldier fly larvae, thus increasing the performance and reliability of black soldier fly larvae rearing. We discuss in detail the possible applications and limitations of our methods in black soldier fly larvae research.


Assuntos
Digestão , Dípteros/fisiologia , Entomologia/métodos , Interações entre Hospedeiro e Microrganismos , Animais , Dieta , Dípteros/crescimento & desenvolvimento , Dípteros/microbiologia , Entomologia/instrumentação , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Reprodutibilidade dos Testes
6.
Nat Commun ; 11(1): 2321, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385305

RESUMO

The diamondback moth, Plutella xylostella is a cosmopolitan pest that has evolved resistance to all classes of insecticide, and costs the world economy an estimated US $4-5 billion annually. We analyse patterns of variation among 532 P. xylostella genomes, representing a worldwide sample of 114 populations. We find evidence that suggests South America is the geographical area of origin of this species, challenging earlier hypotheses of an Old-World origin. Our analysis indicates that Plutella xylostella has experienced three major expansions across the world, mainly facilitated by European colonization and global trade. We identify genomic signatures of selection in genes related to metabolic and signaling pathways that could be evidence of environmental adaptation. This evolutionary history of P. xylostella provides insights into transoceanic movements that have enabled it to become a worldwide pest.


Assuntos
Genoma de Inseto/genética , Herbivoria/genética , Animais , Evolução Biológica , Entomologia/métodos , Genética Populacional/métodos , Filogenia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
7.
J Insect Sci ; 20(3)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32441307

RESUMO

The ability to replicate scientific experiments is a cornerstone of the scientific method. Sharing ideas, workflows, data, and protocols facilitates testing the generalizability of results, increases the speed that science progresses, and enhances quality control of published work. Fields of science such as medicine, the social sciences, and the physical sciences have embraced practices designed to increase replicability. Granting agencies, for example, may require data management plans and journals may require data and code availability statements along with the deposition of data and code in publicly available repositories. While many tools commonly used in replicable workflows such as distributed version control systems (e.g., 'git') or script programming languages for data cleaning and analysis may have a steep learning curve, their adoption can increase individual efficiency and facilitate collaborations both within entomology and across disciplines. The open science movement is developing within the discipline of entomology, but practitioners of these concepts or those desiring to work more collaboratively across disciplines may be unsure where or how to embrace these initiatives. This article is meant to introduce some of the tools entomologists can incorporate into their workflows to increase the replicability and openness of their work. We describe these tools and others, recommend additional resources for learning more about these tools, and discuss the benefits to both individuals and the scientific community and potential drawbacks associated with implementing a replicable workflow.


Assuntos
Entomologia/métodos , Projetos de Pesquisa , Entomologia/instrumentação
8.
BMC Infect Dis ; 20(1): 333, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393183

RESUMO

BACKGROUND: Malaria is a life threating vector borne disease caused by different Plasmodium parasites. Metema and Armachiho are two of the top five malaria endemic areas among the districts of Amhara region in Ethiopia. Transmission pattern is seasonal and migrant laborers who visit these areas for employment in mechanized agriculture are highly affected. The aim of this study was to investigate seasonal abundance, abdominal status and parity rate of An.gambiae s.l in Metema-Armachiho lowlands, Northwest Ethiopia. METHOD: A 1 year longitudinal entomological study was conducted in Metema-Armachiho lowlands from June 2016-May 2017. Mosquitoes were collected using CDC-light traps in indoor and outdoor sites for four consecutive days in each month. A total of eight standard battery operated CDC-light traps were used to collect mosquitoes. Female mosquitoes were classed as unfed, fed or gravid under a dissecting microscope. The ovaries of all unfed An.gambiae s.l mosquitoes were examined for evidence of parity. Data were entered and analyzed using SPSS-20 software. Chi-square test was applied to show significant difference between variables. P-value< 0.05 was taken as statistically significant. RESULTS: Of the total 1253 mosquitoes collected, 713 (552 female, 161 male) were culex and 540 (501 female, 39 male) were An.gambiae s.l. About 50.9% were collected in June-August 2016, 21.7% in September-November 2016, 12.0% in December 2016-February 2017 and 15.4% in March to May 2017. Of the total, 57.2 and 42.8% of the An.gambiae s.l were collected from indoor and outdoor sites respectively. Of the total females collected, 76.8% were unfed; of which 69.4% were parous. Significantly higher number of female An.gambiae s.l were collected in indoor and there was significant difference in abdominal status of An.gambiae s.l mosquitoes collected in different season (P < 0.05). CONCLUSIONS: Highest number of An.gambiae s.l was observed from June-August followed by September-November. The parity rate of An.gambiae s.l was high and there was significant difference in abdominal status of An.gambiae s.l collected in different season.


Assuntos
Anopheles/parasitologia , Malária/epidemiologia , Malária/transmissão , Mosquitos Vetores/parasitologia , Paridade , Estações do Ano , Animais , Entomologia/métodos , Etiópia/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Malária/parasitologia , Masculino , Plasmodium , Gravidez
9.
Parasit Vectors ; 13(1): 160, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228670

RESUMO

BACKGROUND: Practical, field-ready age-grading tools for mosquito vectors of disease are urgently needed because of the impact that daily survival has on vectorial capacity. Previous studies have shown that near-infrared spectroscopy (NIRS), in combination with chemometrics and predictive modeling, can forecast the age of laboratory-reared mosquitoes with moderate to high accuracy. It remains unclear whether the technique has utility for identifying shifts in the age structure of wild-caught mosquitoes. Here we investigate whether models derived from the laboratory strain of mosquitoes can be used to predict the age of mosquitoes grown from pupae collected in the field. METHODS: NIRS data from adult female Aedes albopictus mosquitoes reared in the laboratory (2, 5, 8, 12 and 15 days-old) were analysed against spectra from mosquitoes emerging from wild-caught pupae (1, 7 and 14 days-old). Different partial least squares (PLS) regression methods trained on spectra from laboratory mosquitoes were evaluated on their ability to predict the age of mosquitoes from more natural environments. RESULTS: Models trained on spectra from laboratory-reared material were able to predict the age of other laboratory-reared mosquitoes with moderate accuracy and successfully differentiated all day 2 and 15 mosquitoes. Models derived with laboratory mosquitoes could not differentiate between field-derived age groups, with age predictions relatively indistinguishable for day 1-14. Pre-processing of spectral data and improving the PLS regression framework to avoid overfitting can increase accuracy, but predictions of mosquitoes reared in different environments remained poor. Principal components analysis confirms substantial spectral variations between laboratory and field-derived mosquitoes despite both originating from the same island population. CONCLUSIONS: Models trained on laboratory mosquitoes were able to predict ages of laboratory mosquitoes with good sensitivity and specificity though they were unable to predict age of field-derived mosquitoes. This study suggests that laboratory-reared mosquitoes do not capture enough environmental variation to accurately predict the age of the same species reared under different conditions. Further research is needed to explore alternative pre-processing methods and machine learning techniques, and to understand factors that affect absorbance in mosquitoes before field application using NIRS.


Assuntos
Culicidae/química , Culicidae/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Aedes/química , Aedes/fisiologia , Animais , Vetores de Doenças , Entomologia/métodos , Feminino , Aprendizado de Máquina , Mosquitos Vetores/química , Mosquitos Vetores/fisiologia , Especificidade da Espécie
10.
PLoS Negl Trop Dis ; 14(3): e0008130, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32130209

RESUMO

BACKGROUND: Yellow fever, dengue, chikungunya and Zika viruses are responsible for considerable morbidity and mortality in humans. Aedes aegypti and Aedes albopictus are the most important mosquito vectors involved in their transmission. Accurate identification of these species is essential for the implementation of control programs to limit arbovirus transmission, during suspected detections at ports of first entry, to delimit incursions or during presence/absence surveillance programs in regions vulnerable to invasion. We developed and evaluated simple and rapid colorimetric isothermal tests to detect these two mosquito species based on loop-mediated isothermal amplification (LAMP) targeting the ribosomal RNA internal transcribed spacer 1 (ITS1). METHODOLOGY/PRINCIPAL FINDINGS: Samples were prepared by homogenizing and heating at 99 oC for 10 min before an aliquot was added to the LAMP reaction. After 40 min incubation at 65 oC, a colour change indicated a positive result. The tests were 100% sensitive and species-specific, and demonstrated a limit of detection comparable with PCR-based detection (TaqMan chemistry). The LAMP assays were able to detect target species for various life stages tested (adult, 1st instar larva, 4th instar larva and pupa), and body components, such as legs, wings and pupal exuviae. Importantly, the LAMP assays could detect Ae. aegypti DNA in mosquitoes stored in Biogents Sentinel traps deployed in the field for 14 d. A single 1st instar Ae. aegypti larva could also be detected in a pool of 1,000 non-target 1st instar Aedes notoscriptus, thus expediting processing of ovitrap collections obtained during presence/absence surveys. A simple syringe-sponge protocol facilitated the concentration and collection of larvae from the ovitrap water post-hatch. CONCLUSIONS/SIGNIFICANCE: We describe the development of LAMP assays for species identification and demonstrate their direct application for surveillance in different field contexts. The LAMP assays described herein are useful adjuncts to laboratory diagnostic testing or could be employed as standalone tests. Their speed, ease-of-use, low cost and need for minimal equipment and training make the LAMP assays ideal for adoption in low-resource settings without the need to access diagnostic laboratory services.


Assuntos
Aedes/classificação , Aedes/crescimento & desenvolvimento , Colorimetria/métodos , Entomologia/métodos , Técnicas de Diagnóstico Molecular/métodos , Mosquitos Vetores/classificação , Mosquitos Vetores/crescimento & desenvolvimento , Técnicas de Amplificação de Ácido Nucleico/métodos , Aedes/genética , Animais , DNA Espaçador Ribossômico/genética , Feminino , Mosquitos Vetores/genética , Sensibilidade e Especificidade
11.
J Insect Sci ; 20(2)2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32186741

RESUMO

Trees host a large share of the global arthropod diversity. Several methodologies have been described to sample arthropods from trees, ranging from active sampling techniques (e.g., visual searching, beating, or shaking the branches) to passive sampling devices. The majority of these collection techniques are destructive, and do not specifically target the tree trunk arthropod fauna. Here, we describe an alternative sampling method called trunk refugia (TR). TR are cylindrical shelters made of corrugated cardboard that can be secured to trees using string, and can remain exposed for varying time periods. These refugia are inexpensive, easy to use, and suitable to monitor a diverse array of insects and arachnids. Moreover, TR are nonlethal sampling tools, and allow collecting live individuals for behavioral studies or for rearing.


Assuntos
Artrópodes , Biodiversidade , Conservação dos Recursos Naturais/métodos , Entomologia/métodos , Refúgio de Vida Selvagem , Árvores , Animais
12.
J Insect Sci ; 20(2)2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32191794

RESUMO

A follow-up study was conducted to further evaluate the marking efficiency of broadcast spray applications of egg albumin (from chicken egg whites) on Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae) in alfalfa. A previous study recorded exceptional marking efficiency (e.g., >95% of the population) on H. convergens when using relatively high concentrations (10 to 50%) of chicken egg whites. The present study examines marking efficiency of egg whites using lower concentrations of 2.5, 5.0, and 10.0%. We used cadaver and free-roaming beetles to measure protein mark acquisition (and retention) of each protein concentration by direct contact with the spray application and incidental contact with protein residue on the plant tissue, respectively. The vertical distribution of the protein mark was also determined by sampling the upper and lower portions of the alfalfa canopy. The data indicate, regardless of the egg white treatment, that the backpack sprayer provided uniform coverage of egg albumin on the alfalfa plants and cadaver beetles. Also, almost every free-roaming beetle acquired a mark within 24 h after contact exposure to protein marked plants. This study shows that a very low concentration of egg albumin is sufficient for marking arthropods directly in the field.


Assuntos
Albuminas/análise , Proteínas do Ovo/análise , Entomologia/métodos , Controle de Insetos/métodos , Animais , Galinhas , Besouros
13.
Parasit Vectors ; 13(1): 150, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209116

RESUMO

BACKGROUND: Several mosquito collection methods are routinely used in vector control programmes. However, they target different behaviours causing bias in estimation of species diversity and abundance. Given the paucity of mosquito trap data in West Africa, we compared the performance of five trap-lure combinations and Human Landing Catches (HLCs) in Guinea. METHODS: CDC light traps (LT), BG sentinel 2 traps (BG2T), gravid traps (GT) and Stealth traps (ST) were compared in a 5 × 5 Latin Square design in three villages in Guinea between June and July 2018. The ST, a portable trap which performs similarly to a LT but incorporates LEDs and incandescent light, was included since it has not been widely tested. BG2T were used with BG and MB5 lures instead of CO2 to test the efficacy of these attractants. HLCs were performed for 5 nights, but not as part of the Latin Square. A Generalised Linear Mixed Model was applied to compare the effect of the traps, sites and collection times on mosquito abundance. Species identification was confirmed using PCR-based analysis and Sanger sequencing. RESULTS: A total of 10,610 mosquitoes were captured across five traps. ST collected significantly more mosquitoes (7096) than the rest of the traps, but resulted in a higher number of damaged specimens. ST and BG2T collected the highest numbers of Anopheles gambiae (s.l.) and Aedes aegypti mosquitoes, respectively. HLCs captured predominantly An. coluzzii (41%) and hybrids of An. gambiae and An. coluzzii (36%) in contrast to the five traps, which captured predominantly An. melas (83%). The rural site (Senguelen) presented the highest abundance of mosquitoes and overall diversity in comparison with Fandie (semi-rural) and Maferinyah Centre I (semi-urban). Our results confirm the presence of four species for the first time in Guinea. CONCLUSIONS: ST collected the highest number of mosquitoes suggesting this trap may play an important role for mosquito surveillance in Guinea and similar sites in West Africa. We recommend the incorporation of molecular tools in entomological studies since they have helped to identify 25 mosquito species in this area.


Assuntos
Culicidae , Entomologia/instrumentação , Entomologia/métodos , Animais , Anopheles , Biodiversidade , Dióxido de Carbono , Culicidae/classificação , Feminino , Guiné , Humanos , Luz , Masculino , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Pesquisa
14.
Curr Opin Insect Sci ; 38: 15-25, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32086017

RESUMO

Our review looks at recent advances in technologies applied to studying pollinators in the field. These include RFID, radar and lidar for detecting and tracking pollinators; wireless sensor networks (e.g. 'smart' hives); automated visual and audio monitoring systems including vision motion software for monitoring fine-scale pollinator behaviours over extended periods; and automated species identification systems based on machine learning that can vastly reduce the bottleneck in (big) data analysis. An improved e-ecology platform that leverages these tools is needed for ecologists to acquire and understand large spatiotemporal datasets, and thus inform knowledge gaps in environmental policy-making. Developing the next generation of e-ecology tools will require synergistic partnerships between academia and industry and significant investment in a cross-disciplinary scientific consortia.


Assuntos
Ecologia/métodos , Entomologia/métodos , Insetos/fisiologia , Polinização , Tecnologia/métodos , Agricultura/instrumentação , Agricultura/métodos , Animais , Ecologia/instrumentação , Entomologia/instrumentação , Tecnologia/instrumentação
15.
Sci Rep ; 10(1): 741, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959845

RESUMO

One of the key determinants of a haematophagous vector's capacity to transmit pathogens is its selection of which host to secure a blood meal from. This choice is influenced by both intrinsic (genetic) and extrinsic (environmental) factors, but little is known of their relative contributions. Blood fed Anopheles mosquitoes were collected from a malaria endemic village in Ghana. Collections were conducted across a range of different host availabilities and from both indoor and outdoor locations. These environmental factors were shown to impact dramatically the host choice of caught malaria vectors: mosquitoes caught indoors were ten-fold more likely to have sourced their blood meal from humans; and a halving in odds of being human-fed was found for mosquitoes caught only 25 m from the centre of the village. For the first time, we demonstrate that anthropophagy was better explained by extrinsic factors (namely, local host availability and indoor/outdoor trapping location) than intrinsic factors (namely, the (sibling) species of the mosquito caught) (respective Akaike information criterion estimates: 243.0 versus 359.8). Instead of characterizing biting behaviour on a taxonomic level, we illustrate the importance of assessing local entomology. Accounting for this behavioural plasticity is important, both in terms of measuring effectiveness of control programmes and in informing optimal disease control strategies.


Assuntos
Anopheles/fisiologia , Sangue , Entomologia/métodos , Meio Ambiente , Comportamento Alimentar , Preferências Alimentares , Interações Hospedeiro-Parasita , Mordeduras e Picadas de Insetos , Malária/transmissão , Controle de Mosquitos/métodos , Mosquitos Vetores , Animais , Gana , Humanos
16.
Sci Rep ; 10(1): 1012, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974419

RESUMO

Image-based automatic classification of vector mosquitoes has been investigated for decades for its practical applications such as early detection of potential mosquitoes-borne diseases. However, the classification accuracy of previous approaches has never been close to human experts' and often images of mosquitoes with certain postures and body parts, such as flatbed wings, are required to achieve good classification performance. Deep convolutional neural networks (DCNNs) are state-of-the-art approach to extracting visual features and classifying objects, and, hence, there exists great interest in applying DCNNs for the classification of vector mosquitoes from easy-to-acquire images. In this study, we investigated the capability of state-of-the-art deep learning models in classifying mosquito species having high inter-species similarity and intra-species variations. Since no off-the-shelf dataset was available capturing the variability of typical field-captured mosquitoes, we constructed a dataset with about 3,600 images of 8 mosquito species with various postures and deformation conditions. To further address data scarcity problems, we investigated the feasibility of transferring general features learned from generic dataset to the mosquito classification. Our result demonstrated that more than 97% classification accuracy can be achieved by fine-tuning general features if proper data augmentation techniques are applied together. Further, we analyzed how this high classification accuracy can be achieved by visualizing discriminative regions used by deep learning models. Our results showed that deep learning models exploit morphological features similar to those used by human experts.


Assuntos
Aedes/classificação , Culex/classificação , Aprendizado Profundo , Mosquitos Vetores/classificação , Aedes/anatomia & histologia , Aedes/microbiologia , Animais , Culex/anatomia & histologia , Culex/microbiologia , Transmissão de Doença Infecciosa , Entomologia/métodos , Processamento de Imagem Assistida por Computador/métodos , Mosquitos Vetores/microbiologia
17.
Med Vet Entomol ; 34(1): 27-33, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31432538

RESUMO

When computing mean daily fertility in adult female tsetse, the common practice of taking the reciprocal of the interlarval period (called averaged fertility) was compared with the method of taking the sum of the products of daily fertility and adult survivorship divided by the sum of daily survivorships (called periodic fertility). The latter method yielded a consistently higher measure of fertility (approximately 10% for tsetse) than the former method. A conversion factor was calculated to convert averaged fertility to periodic fertility. A feasibility criterion was determined for the viability of a tsetse population. Fertility and survivorship data from tsetse populations on Antelope Is. and Redcliff Is., both in Zimbabwe, were used to illustrate the feasibility criterion, as well as the limitations imposed by survivorship and fertility on the viability of tsetse populations. The 10% difference in fertility between the two methods of calculation makes the computation of population feasibility with some parameter combinations sometimes result in a wrong answer. It also underestimates both sterile male release rates required to eradicate a pest population, as well as the speed of resurgence if an eradication attempt fails.


Assuntos
Entomologia/métodos , Moscas Tsé-Tsé/fisiologia , Animais , Feminino , Fertilidade , Controle de Insetos , Masculino , Modelos Biológicos , Reprodução , Zimbábue
18.
Microb Ecol ; 79(2): 472-481, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31300838

RESUMO

Maternally inherited bacterial endosymbionts are common in arthropods, but their distribution and prevalence are poorly characterized in many host taxa. Initial surveys have suggested that vertically transmitted symbionts may be particularly common in spiders (Araneae). Here, we used diagnostic PCR and high-throughput sequencing to evaluate symbiont infection in 267 individual spiders representing 14 species (3 families) of agricultural spiders. We found 27 operational taxonomic units (OTUs) that are likely endosymbiotic, including multiple strains of Wolbachia, Rickettsia, and Cardinium, which are all vertically transmitted and frequently associated with reproductive manipulation of arthropod hosts. Additional strains included Rickettsiella, Spiroplasma, Rhabdochlamydia, and a novel Rickettsiales, all of which could range from pathogenic to mutualistic in their effects upon their hosts. Seventy percent of spider species had individuals that tested positive for one or more endosymbiotic OTUs, and specimens frequently contained multiple symbiotic strain types. The most symbiont-rich species, Idionella rugosa, had eight endosymbiotic OTUs, with as many as five present in the same specimen. Individual specimens within infected spider species had a variety of symbiotypes, differing from one another in the presence or absence of symbiotic strains. Our sample included both starved and unstarved specimens, and dominant bacterial OTUs were consistent per host species, regardless of feeding status. We conclude that spiders contain a remarkably diverse symbiotic microbiota. Spiders would be an informative group for investigating endosymbiont population dynamics in time and space, and unstarved specimens collected for other purposes (e.g., food web studies) could be used, with caution, for such investigations.


Assuntos
Bactérias/isolamento & purificação , Técnicas Bacteriológicas/métodos , Entomologia/métodos , Microbiota , Aranhas/microbiologia , Simbiose/fisiologia , Animais , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Privação de Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Kentucky , Microbiota/genética , Reação em Cadeia da Polimerase
19.
Parasitology ; 147(3): 329-339, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31840617

RESUMO

BACKGROUND: The accurate and rapid identification of mosquito blood meals is critical to study the interactions between vectors and vertebrate hosts and, subsequently, to develop vector control strategies. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling has been shown to be a reliable and effective tool for identifying single blood meals from mosquitoes. METHODS: In this study, we developed MALDI-TOF MS profiling protocols to identify Anopheles gambiae Giles, Anopheles coluzzii and Aedes albopictus mosquitoes' mixed blood meals and the last of successive blood meals. The mosquitoes were either successively artificially fed with distinct host bloods or engorged with mixed bloods from distinct vertebrate hosts, such as humans, sheep and dogs. RESULTS: Blind test analyses revealed a correct identification of mixed blood meals from mosquitoes using MALDI-TOF MS profiling. The 353 MS spectra from mixed blood meals were identified using log score values >1.8. All MS spectra (n = 244) obtained from mosquitoes' successive blood meals were reproducible and specific to the last blood meal, suggesting that the previous blood meals do not have an impact on the identification of the last one. CONCLUSION: MALDI-TOF MS profiling approach appears to be an effective and robust technique to identify the last and mixed blood meals during medical entomological surveys.


Assuntos
Aedes/fisiologia , Anopheles/fisiologia , Entomologia/métodos , Mosquitos Vetores/fisiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Aedes/química , Animais , Anopheles/química , Análise Química do Sangue , Dieta , Cães , Comportamento Alimentar , Humanos , Mosquitos Vetores/química , Ovinos , Especificidade da Espécie
20.
Parasit Vectors ; 12(1): 584, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842984

RESUMO

BACKGROUND: Blood meal host selection by mosquito vectors is an important component in understanding disease dynamics of pathogens that threaten endemic fauna in isolated islands such as Galápagos. Research on the feeding behavior of mosquitoes can provide clues to the hosts and vectors involved in disease transmission. This information is particularly critical for endemic wildlife fauna in island systems that have evolved without resistance to novel diseases such as avian malaria. The aims of this study were to determine the blood-feeding patterns of two species of mosquitoes found in Galápagos and discuss how their feeding behavior may influence the transmission of pathogens such as avian malaria. METHODS: In the summer of 2015, we sampled two mosquito species (Aedes taeniorhynchus and Culex quinquefasciatus) across 18 different sites on Isla Santa Cruz, which is the second largest island in Galápagos and has the largest human population. We trapped mosquitoes using CDC light traps and CDC gravid traps and identified sources of blood meals for engorged mosquitoes by sequencing a portion of the vertebrate mitochondrial cytochrome b gene. RESULTS: Out of 947 female mosquitoes captured, 320 were blood-fed, and PCR amplifications were successful for 301 of the blood meals. Results revealed that both Aedes taeniorhynchus and Culex quinquefasciatus feed from a variety of vertebrate taxa, numerically dominated by humans on Isla Santa Cruz. CONCLUSIONS: The high proportion of mammalian blood meals could represent locally available and abundant hosts on Santa Cruz. However, host surveys and estimates of relative abundances of vertebrate species will need to accompany mosquito trapping studies on non-inhabited and inhabited islands in Galápagos to further validate this.


Assuntos
Aedes/fisiologia , Culex/fisiologia , Comportamento Alimentar , Mosquitos Vetores/fisiologia , Animais , Citocromos b/genética , Equador , Entomologia/métodos , Enzimas/sangue , Enzimas/genética , Técnicas de Genotipagem/métodos , Humanos , Mamíferos
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