Urban heat islands are characterized by high land surface temperature, low humidity, and poor vegetation, and considered to favor the transmission of the mosquito-borne dengue fever that is transmitted by the Aedes aegypti mosquito. We analyzed the recorded dengue incidence in Sao Paulo city, Brazil, in 2010-2011, in terms of multiple environmental and socioeconomic variables. Geographical information systems, thermal remote sensing images, and census data were used to classify city areas according to land surface temperature, vegetation cover, population density, socioeconomic status, and housing standards. Of the 7415 dengue cases, a majority (93.1%) mapped to areas with land surface temperature >28°C. The dengue incidence rate (cases per 100,000 inhabitants) was low (3.2 cases) in high vegetation cover areas, but high (72.3 cases) in low vegetation cover areas where the land surface temperature was 29±2°C. Interestingly, a multiple cluster analysis phenogram showed more dengue cases clustered in areas of land surface temperature >32°C, than in areas characterized as low socioeconomic zones, high population density areas, or slum-like areas. In laboratory experiments, A. aegypti mosquito larval development, blood feeding, and oviposition associated positively with temperatures of 28-32°C, indicating these temperatures to be favorable for dengue transmission. Thus, among all the variables studied, dengue incidence was most affected by the temperature.

The field of morphometrics is developing quickly. Recent advances have enabled geometric techniques to be applied to many zoological problems, particularly those involving epidemiologically-relevant mosquitoes. Herein, we briefly introduce geometric morphometric (GM) techniques and then review selected groups of mosquitoes (Culicidae) to which those techniques have been applied. In most of the reviewed cases, GM was capable of satisfactorily discriminating among the tested groups primarily when the studies considered differences within and among species, sexual dimorphism, treatments and the separation of laboratory strains. Although GM approaches have developed quite rapidly, some caution must be taken during data processing for a reliable biometrical approach, such as allometry and asymmetry analyses, scale removal and wing clarification staining for landmark digitization. We also critically forecast directions in this field and discuss how the creation of image databases should enhance species identification in culicids.

Background: Mosquito larvae feed on organic detritus from the environment, particularly microorganisms comprising bacteria, protozoa, and algae as well as crustaceans, plant debris, and insect exuviae. Little attention has been paid to nutritional studies in Aedes aegypti larvae. Objectives: We investigated the effects of yeast, bacteria and microalgae diets on larval development, pupation time, adult size, emergence, survivorship, lifespan, and wing morphology. Material and Methods: Microorganisms (or Tetramin® as control) were offered as the only source of food to recently hatched first instar larvae and their development was followed until the adult stage. Protein, carbohydrate, glycogen, and lipid were analyzed in single larvae to correlate energetic reserve accumulation by larva with the developmental rates and nutritional content observed. FITC-labeled microorganisms were offered to fourth instar larvae, and its ingestion was recorded by fluorescence microscopy and quantitation. Results and Discussion: Immature stages developed in all diets, however larvae fed with bacteria and microalgae showed a severe delay in development rates, pupation time, adult emergence and low survivorship. Adult males emerged earlier as expected and had longer survival than females. Diets with better nutritional quality resulted in adults with bigger wings. Asaia sp. and Escherichia coli resulted in better nutrition and developmental parameters and seemed to be the best bacterial candidates to future studies using symbiont-based control. The diet quality was measured and presented different protein and carbohydrate amounts. Bacteria had the lowest protein and carbohydrate rates, yeasts had the highest carbohydrate amount and microalgae showed the highest protein content. Larvae fed with microalgae seem not to be able to process and store these diets properly. Larvae were shown to be able to process yeast cells and store their energetic components efficiently. Conclusion: Together, our results point that Ae .aegypti larvae show high plasticity to feed, being able to develop under different microorganism-based diets. The important role of Ae. aegypti in the spread of infectious diseases requires further biological studies in order to understand the vector physiology and thus to manage the larval natural breeding sites aiming a better mosquito control.

The ability to successfully identify and incriminate pathogen vectors is fundamental to effective pathogen control and management. This task is confounded by the existence of cryptic species complexes. Molecular markers can offer a highly effective means of species identification in such complexes and are routinely employed in the study of medical entomology. Here we evaluate a multi-locus system for the identification of potential malaria vectors in the Anopheles strodei subgroup.

The worldwide expansion of new emergent arboviruses such as Chikungunya and Zika reinforces the importance in understanding the role of mosquito species in spreading these pathogens in affected regions. This knowledge is essential for developing effective programs based on species specificity to avoid the establishment of endemic transmission cycles sustained by the identified local vectors. Although the first autochthonous transmission of Chikungunya virus was described in 2014 in the north of Brazil, the main outbreaks were reported in 2015 and 2016 in the northeast of Brazil. During 5 days of February 2016, we collected mosquitoes in homes of 6 neighborhoods of Aracaju city, the capital of Sergipe state. Four mosquito species were identified but Culex quinquefasciatus and Aedes aegypti were the most abundant. Field-caught mosquitoes were tested for Chikungunya (CHIKV), Zika (ZIKV) and Dengue viruses (DENV) by qRT-PCR and one CHIKV-infected Ae. aegypti female was detected. The complete sequence of CHIKV genome was obtained from this sample and phylogenetic analysis revealed that this isolate belongs to the East-Central-South-African (ECSA) genotype. Our study describes the first identification of a naturally CHIKV-infected Ae. aegypti in Brazil and the first report of a CHIKV from ECSA genotype identified in this species in the Americas. These findings support the notion of Ae. aegypti being a vector involved in CHIKV outbreaks in northeast of Brazil. The chikungunya outbreaks have become one of the main public health problems in the Northeast Region of Brazil. Since the chikungunya virus (CHIKV) was recently introduced in this country, finding vector associations involved in its transmission to the vertebrate host is primordial to better design efficient intervention against mosquitoes. In the present study, field-caught mosquitoes in Aracaju city, Sergipe State, Brazil were evaluated for the presence of CHIKV and other two endemic arboviruses (Zika and Dengue viruses) in this region. We described here the first identification of the East-Central-South-African (ECSA) CHIKV genotype naturally infecting Aedes aegypti mosquitoes in Brazil. This work suggests the involvement of this species in CHIKV outbreaks in Northeast Region of this country and reveals a possible interaction between this vector and the recently introduced CHIKV ECSA genotype.

Background: Anopheles(Kerteszia)cruziiis a primary vector ofPlasmodiumparasites in Brazil’s Atlantic Forest. Adult females ofAn. cruziiandAn. homunculus, which is a secondary malaria vector, are morphologically similar and difficult to distinguish when using external morphological characteristics only. These two species may occur syntopically withAn.bellator, which is also a potential vector ofPlasmodiumspecies and is morphologically similar toAn. cruziiandAn. homunculus. Identification of these species based on female specimens is often jeopardised by polymorphisms, overlapping morphological characteristics and damage caused to specimens during collection. Wing geometric morphometrics has been used to distinguish several insect species; however, this economical and powerful tool has not been applied toKertesziaspecies. Our objective was to assess wing geometry to distinguishAn. cruzii,An. homunculusandAn. bellator.Methods: Specimens were collected in an area in the Serra do Mar hotspot biodiversity corridor of the Atlantic Forest biome (Cananeia municipality, State of Sao Paulo, Brazil). The right wings of females ofAn. cruzii(n= 40),An. homunculus(n= 50) andAn. bellator(n= 27) were photographed. For each individual, 18 wing landmarks were subjected to standard geometric morphometrics. Discriminant analysis of Procrustean coordinates was performed to quantify wing shape variation.Results: Individuals clustered into three distinct groups according to species with a slight overlap between representatives ofAn. cruziiandAn. homunculus. The Mahalanobis distance betweenAn. cruziiandAn. homunculuswas consistently lower (3.50) than that betweenAn. cruziiandAn. bellator(4.58) orAn. homunculusandAn. bellator(4.32). Pairwise cross-validated reclassification showed that geometric morphometrics is an effective analytical method to distinguish betweenAn.bellator,An. cruziiandAn. homunculuswith a reliability rate varying between 78-88%. Shape analysis revealed that the wings ofAn. homunculusare narrower than those ofAn. cruziiand thatAn. bellatoris different from both of the congeneric species.Conclusion: It is possible to distinguish among the vectorsAn. cruzii,An. homunculusandAn. bellatorbased on female wing characteristics.