LSTM-Based Mosquito Genus Classification Using Their Wingbeat Sound

In this paper, we propose Long-Short Term Memory (LSTM)-based mosquito’s genus classification, in which the time-frequency features are extracted from the wingbeat sound of mosquitos of three genera, Aedes, Anopheles and Culex. The extracted features are fed into the proposed LSTM-based classifier. We evaluated three time-frequency features, which are: Mel Spectrogram, Log-Mel spectrogram, and Mel-frequency Cepstral Coefficients (MFCC). The proposed scheme is composed by two LSTM layers and one Fully Connected layer connected to a SoftMax activation function. The classification accuracies using the three features are 92.97(±0.2)%, 96.71(±0.2)% and 96.65(±0.2)%, respectively. The Area Under Curve (AUC) of the Receiver Operating Characteristics (ROC) for each feature are also obtained, which are 0.9944, 0.9986 and 0.9987, respectively. The proposed classifier requires approximately 62,000 trainable parameters. This number is much smaller than that required for the state-of-arts CNNs, such as AlexNet and Vgg16. This compact configuration of the proposed scheme takes advantage of the mobile and IoT implementation, because the number of trainable parameters is directly proportional to the amount of memory and CPU required.

MAMOTH: An Earth Observational Data-Driven Model for Mosquitoes Abundance Prediction

Mosquito-Borne Diseases (MBDs) are known to be more prevalent in the tropics, and yet, in the last two decades, they are spreading to many other countries, especially in Europe. The set (volume) of environmental, meteorological and other spatio-temporally variable parameters affecting mosquito abundance makes the modeling and prediction tasks quite challenging. Up to now, mosquito abundance prediction problems were addressed with ad-hoc area-specific and genus-tailored approaches. We propose and develop MAMOTH, a generic and accurate Machine Learning model that predicts mosquito abundances for the upcoming period (the Mean Absolute Error of the predictions do not deviate more than 14%). The designed model relies on satellite Earth Observation and other in-situ geo-spatial data to tackle the problem. MAMOTH is not site- nor mosquito genus-dependent; thus, it can be easily replicated and applied to multiple cases without any special parametrization. The model was applied to different mosquito genus and species Culex spp. as potential vectors for West Nile Virus, Anopheles spp. for Malaria and Aedes albopictus for Zika/Chikungunya/Dengue) and in different areas of interest (Italy, Serbia, France, Germany). The results show that the model performs accurately and consistently for all case studies. Additionally, the evaluation of different cases, with the model using the same principles, provides an opportunity for multi-case and multi-scope comparative studies.

Toxorhynchites Species: A Review of Current Knowledge

The increasing global incidence of mosquito-borne infections is driving a need for effective control methods. Vector populations have expanded their geographical ranges, while increasing resistance to chemical insecticides and a lack of effective treatments or vaccines has meant that the development of vector control methods is essential in the fight against mosquito-transmitted diseases. This review will focus on Toxorhynchites, a non-hematophagous mosquito genus which is a natural predator of vector species and may be exploited as a biological control agent. Their effectiveness in this role has been strongly debated for many years and early trials have been marred by misinformation and incomplete descriptions. Here, we draw together current knowledge of the general biology of Toxorhynchites and discuss how this updated information will benefit their role in an integrated vector management program.

Screening for Viruses and Lemur-Associated Filara in Wild-Caught Mosquitoes From Madagascar

Madagascar is a hotspot of biodiversity, but poverty and population growth provoke a high risk of conflict between food security and biodiversity conservation in this tropical country. Numerous vector-borne diseases, including viral infections, affect public health in Madagascar and a continuous expansion of anthropogenically used areas intensifies contact on the human–wildlife interface. However, data on human and animal pathogens in potential insect vectors is limited. Therefore, we conducted a parasitological and virological survey of 785 adult female mosquitoes between March and May 2016 at the Ankarafantsika National Park in northwestern Madagascar. Screening included Alpha-, Phlebo-, and Flaviviridae and the recently described filarial nematode species, Lemurfilaria lemuris. The predominant mosquito genus was Culex (91%), followed by Mansonia (4.1%), Anopheles (3.4%), and Aedes (0.9%). Viral screening revealed no arboviruses, but an insect-specific flavivirus in two Culex sitiens pools. No pools screened positive for the lemur-specific filarial nematode L. lemuris.

Taxonomic history of species without subgeneric placement in the genus Wyeomyia Theobald (Diptera: Culicidae) and recognition of Wy. compta Senevet & Abonnenc as a junior synonym of Wy. argenteorostris (Bonne-Wepster & Bonne)

The mosquito genus Wyeomyia (Diptera: Culicidae) includes 17 subgenera and 140 species, 30 of which are without subgeneric placement. The taxonomic history of the unplaced species is summarized and the validity of Wy. compta Senevet & Abonnenc is discussed based on examination of the type material. It is clear that the description of Wy. compta was based on specimens belonging to two different species. The holotype adult female is identical to Wy. argenteorostris (Bonne-Wepster & Bonne) whereas the characters described from a larval exuviae mounted on the same slide with the holotype of Wy. albocaerulea Senevet & Abonnenc coincide with those which characterize the subgenus Dodecamyia. Since the larval exuviae cannot be definitely associated with the holotype female and it belongs to either Wy. aphobema Dyar or another species of the subgenus Dodecamyia, it cannot be afforded type status. Therefore, Wy. compta is synonymized with Wy. argenteorostris.

A New Clade of Insect-Specific Flaviviruses from Australian Anopheles Mosquitoes Displays Species-Specific Host Restriction

ABSTRACT Flaviviruses like dengue, Zika, or West Nile virus infect millions of people each year and are transmitted to humans via infected-mosquito bites. A subset of flaviviruses can only replicate in the mosquito host, and recent studies have shown that some can interfere with pathogenic flaviviruses in mosquitoes and limit the replication and transmission of the latter. The insect-specific flaviviruses (ISFs) reported here form a new Anopheles mosquito-associated clade separate from the Aedes- and Culex-associated ISF clades. The identification of distinct clades for each mosquito genus provides new insights into the evolution and ecology of flaviviruses. One of these viruses was shown to replicate in the midgut of the mosquito host and exhibit the most specialized host restriction reported to date for ISFs. Understanding this unprecedented host restriction in ISFs could help identify the mechanisms involved in the evolution of flaviviruses and their emergence as mosquito-borne pathogens. Flaviviruses are arthropod-borne viruses found worldwide and are responsible for significant human and veterinary diseases, including dengue, Zika, and West Nile fever. Some flaviviruses are insect specific and replicate only in mosquitoes. We report a genetically divergent group of insect-specific flaviviruses from Anopheles mosquitoes that do not replicate in arthropod cell lines or heterologous Anopheles species, exhibiting unprecedented specialization for their host species. Determination of the complete sequences of the RNA genomes of three of these viruses, Karumba virus (KRBV), Haslams Creek virus, and Mac Peak virus (McPV), that are found in high prevalence in some Anopheles mosquito populations and detection of virus-specific proteins, replicative double-stranded RNA, and small interfering RNA responses in the host mosquito species provided strong evidence of a functional replicating virus in the mosquito midgut. Analysis of nucleotide composition in the KRBV and McPV sequences also revealed a pattern consistent with the virus evolving to replicate only in insects. These findings represent a significant advance in our knowledge of mosquito-borne flavivirus ecology, host restriction, and evolution. IMPORTANCE Flaviviruses like dengue, Zika, or West Nile virus infect millions of people each year and are transmitted to humans via infected-mosquito bites. A subset of flaviviruses can only replicate in the mosquito host, and recent studies have shown that some can interfere with pathogenic flaviviruses in mosquitoes and limit the replication and transmission of the latter. The insect-specific flaviviruses (ISFs) reported here form a new Anopheles mosquito-associated clade separate from the Aedes- and Culex-associated ISF clades. The identification of distinct clades for each mosquito genus provides new insights into the evolution and ecology of flaviviruses. One of these viruses was shown to replicate in the midgut of the mosquito host and exhibit the most specialized host restriction reported to date for ISFs. Understanding this unprecedented host restriction in ISFs could help identify the mechanisms involved in the evolution of flaviviruses and their emergence as mosquito-borne pathogens.

Towards a new role for vector systematics in parasite control

SUMMARYVector systematics research is being transformed by the recent development of theoretical, experimental and analytical methods, as well as conceptual insights into speciation and reconstruction of evolutionary history. We review this progress using examples from the mosquito genusAnopheles. The conclusion is that recent progress, particularly in the development of better tools for understanding evolutionary history, makes systematics much more informative for vector control purposes, and has increasing potential to inform and improve targeted vector control programmes.