Search

Most of adult female mosquitoes secrete saliva to facilitate blood sucking, digestion and nutrition, and mosquito-borne disease prevention. The knowledge of classification and characteristics of sialotranscriptome genes are still quite limited. Anopheles sinensis is a major malaria vector in China and southeast Asian countries. In this study, the An. sinensis sialotranscriptome was sequenced using Illumina sequencing technique with a total of 10 907 unigenes to be obtained and annotated in biological functions and pathways, and 10 470 unigenes were mapped to An. sinensis reference genome with 70.46% of genes having 90%-100% genomemapping through bioinformatics analysis. Thesemapped genes were classified into four categories: housekeeping (6632 genes), secreted (1177), protein-coding genes with function-unknown (2646) and transposable element (15). The housekeeping genes were divided into 27 classes, and the secreted genes were divided into 11 classes and 96 families. The classification, characteristics and evolution of these classes/families of secreted genes are further described and discussed. The comparison of the 1177 secreted genes in An. sinensis in the Anophelinae subfamily with 811 in Psorophora albipes in the Culicinae subfamily show that six classes/subclasses have the gene number more than twice and two classes (uniquely found in anophelines, and Orphan proteins of unique standing) are unique in the former compared with the latter, whereas four classes/subclasses are much expanded and uniquely found in the Aedes class and is unique in the later. The An. sinensis sialotranscriptome sequence data is the most complete in mosquitoes to date, and the analyses provide a comprehensive information frame for further research of mosquito sialotranscriptome. [ABSTRACT FROM AUTHOR]

Three hundred seventy-seven specimens, distributed in 13 species of mosquitoes, were collected between June and November 2011 in a forest area in the Parque Natural do Vale do Rio do Peixe, Municipality of Joaçaba, Santa Catarina. The three most abundant species were: Aedes crinifer (62.3%), Psorophora ferox (23.6%) e Trichoprosopon pallidiventer (5.1%). Regarding to the abundance and richness of mosquitoes according to the month, it was found that October had the highest abundance of mosquitoes (33.34%), followed by August (23.34%) and November (20.42 %). Concerning to the richness, October had the highest number of species (11), followed by November (9) and August (6). It was also observed the abundance and richness of the collection schedules, and the time between 11 am and 12 am showed higher abundance and richness. In contrast, the time of lowest abundance and richness was from 8 am to 9 am. Three species of Culicidae were firstly reported to the Santa Catarina State (Mansonia indubitans, Sabethes whitmani and Wyeomyia sabethea). The possible medical and veterinary significance of the findings is discussed. [ABSTRACT FROM AUTHOR]

Background Psorophora mosquitoes are exclusively found in the Americas and have been associated with transmission of encephalitis and West Nile fever viruses, among other arboviruses. Mosquito salivary glands represent the final route of differentiation and transmission of many parasites. They also secrete molecules with powerful pharmacologic actions that modulate host hemostasis, inflammation, and immune response. Here, we employed next generation sequencing and proteome approaches to investigate for the first time the salivary composition of a mosquito member of the Psorophora genus. We additionally discuss the evolutionary position of this mosquito genus into the Culicidae family by comparing the identity of its secreted salivary compounds to other mosquito salivary proteins identified so far. Results Illumina sequencing resulted in 13,535,229 sequence reads, which were assembled into 3,247 contigs. All families were classified according to their in silico-predicted function/ activity. Annotation of these sequences allowed classification of their products into 83 salivary protein families, twenty (24.39%) of which were confirmed by our subsequent proteome analysis. Two protein families were deorphanized from Aedes and one from Ochlerotatus, while four protein families were described as novel to Psorophora genus because they had no match with any other known mosquito salivary sequence. Several protein families described as exclusive to Culicines were present in Psorophora mosquitoes, while we did not identify any member of the protein families already known as unique to Anophelines. Also, the Psorophora salivary proteins had better identity to homologs in Aedes (69.23%), followed by Ochlerotatus (8.15%), Culex (6.52%), and Anopheles (4.66%), respectively. Conclusions This is the first sialome (from the Greek sialo = saliva) catalog of salivary proteins from a Psorophora mosquito, which may be useful for better understanding the lifecycle of this mosquito and the role of its salivary secretion in arboviral transmission. [ABSTRACT FROM AUTHOR]

Abstract: Eggs of Psorophora albigenu were analyzed by light and scanning electron microscopy. Eggs were laid singly and were black and elliptical in outline. A length of approximately 586.4±10.83μm, a width of 172.3±8.09μm (n =30), and an egg index (length/width ratio) of 3.33 were observed. The anterior extremity tapered abruptly from a width of 64.9μm, while such tapering was more gradual at the posterior extremity from a width of 77.4μm. The ventral surface of the chorionic coating presented cells with tubular aspect containing tubercles in rows with a density of 9–16 tubercles per cell. These tubercles presented two different sizes, with the largest measuring 7.87±01.58μm and the smallest measuring 0.71±0.53μm (n =30) in longitudinal diameter. The micropyle orifice was very evident, with a diameter of 3.36μm. The morphometric characteristics of Ps. albigenu obtained in this study were distinct from those of other species of the Psorophora genus, including Psorophora varipes which has been considered for a long time to be synonymous with Ps. albigenu. [Copyright &y& Elsevier]

The results of laboratory tests indicated the average survival rates for Psorophora columbiae eggs remained quite high for all of the egg populations exposed to a temperature of 27°C (range 83.0–100.0% survival) after 96 days of exposure, except for the non-diapausing eggs on dry soil (66.3%). In regard to the exposure of egg populations to moderately cold temperatures (i.e. 8°C, 4°C and −2°C) for periods of up to 16 days, survival rates for egg populations exposed to 8°C continued to remain relatively high (average >85%) for the remainder of the experimental exposure period (i.e. 96 days). Diapausing Ps. columbiae eggs were more tolerant (82.0% survival) to low temperatures (−2°C) than non-diapausing eggs (2.4% survival) for 64 days, particularly at temperatures of and below 4°C. Diapausing and non-diapausing eggs were similar in their ability to survive under high temperatures (34°C and 38°C). High soil moisture (30–40%) or substrate moisture (95% relative humidity) content appeared to enhance the ability of the mosquito eggs to survive both low and high temperature extremes. [ABSTRACT FROM AUTHOR]

Hypotheses concerning the developmental plasticity of species that occupy temporary versus permanent aquatic habitats were tested on Psorophora howardii, a mosquito whose predatory larvae occur in ditches flooded for brief periods to irrigate citrus trees in Florida. Responses of P. howardii to experimental variations in temperature and prey availability were compared to those of Toxorhynchites rutilus, a mosquito species whose predatory larvae occupy the relatively permanent waters of treeholes. As predicted, the permanent-water species was more variable in developmental time, and some results suggested that the temporary-habitat predator was more plastic in weight at pupation. Survival of P. howardii was reduced when prey were scarce, and in the complete absence of prey this species died 7–12 times faster than T. rutilus, probably as a result of the higher energy costs of active versus ambush predation. Adults of P. howardii mated precociously after emergence in cages and lived, on average, only 6–11 days compared to an average life span of 84–93 days for T. rutilus. Information on other temporarywater mosquito species indicates that boom-or-bust development of larvae may be associated frequently with early mating and reduced longevity of adults. [ABSTRACT FROM AUTHOR]

Historical declines in multiple insect taxa have been documented across the globe in relation to landscape-level changes in land use and climate. However, declines have either not been universally observed in all regions or examined for all species. Because mosquitoes are insects of public health importance, we analyzed a longitudinal mosquito surveillance data set from Connecticut (CT), United States (U.S.) from 2001 to 2019 to identify changes in mosquito community composition over time. We first analyzed annual site-level collections and metrics of mosquito community composition with generalized linear/additive mixed effects models; we also examined annual species-level collections using the same tools. We then examined correlations between statewide collections and weather variables as well as site-level collections and land cover classifications. We found evidence that the average trap night collection of mosquitoes has increased by ~ 60% and statewide species richness has increased by ~ 10% since 2001. Total species richness was highest in the southern portion of CT, likely due to the northward range expansion of multiple species within the Aedes, Anopheles, Culex, and Psorophora genera. How the expansion of mosquito populations in the northeast U.S. will alter mosquito-borne pathogen transmission in the region will require further investigation. [ABSTRACT FROM AUTHOR]

Background: The year 1971 was the first time in New York State (NYS) that Eastern equine encephalitis virus (EEEV) was identified in mosquitoes, in Culiseta melanura and Culiseta morsitans. At that time, state and county health departments began surveillance for EEEV in mosquitoes. Methods: From 1993 to 2012, county health departments continued voluntary participation with the state health department in mosquito and arbovirus surveillance. Adult female mosquitoes were trapped, identified, and pooled. Mosquito pools were tested for EEEV by Vero cell culture each of the twenty years. Beginning in 2000, mosquito extracts and cell culture supernatant were tested by reverse transcriptase-polymerase chain reaction (RT-PCR). Results: During the years 1993 to 2012, EEEV was identified in: Culiseta melanura, Culiseta morsitans, Coquillettidia perturbans, Aedes canadensis (Ochlerotatus canadensis), Aedes vexans, Anopheles punctipennis, Anopheles quadrimaculatus, Psorophora ferox, Culex salinarius, and Culex pipiens-restuans group. EEEV was detected in 427 adult mosquito pools of 107,156 pools tested totaling 3.96 million mosquitoes. Detections of EEEV occurred in three geographical regions of NYS: Sullivan County, Suffolk County, and the contiguous counties of Madison, Oneida, Onondaga and Oswego. Detections of EEEV in mosquitoes occurred every year from 2003 to 2012, inclusive. EEEV was not detected in 1995, and 1998 to 2002, inclusive. Conclusions: This was the first time in NYS that EEEV was detected in Cx. salinarius, Ps. ferox and An. punctipennis. The detection of EEEV in mosquitoes every year for 10 years was the longest time span since surveillance began in 1971. The calendar date of the earliest annual appearance of EEEV in mosquitoes did not change during surveillance spanning 42 years. [ABSTRACT FROM AUTHOR]