New genome sequence to provide insight into tiger mosquito and how deadly diseases are transmitted to humans

Pathogens and Global Health journal has just published details of the first draft genome sequence of Aedes albopictus, commonly known as the tiger mosquito and responsible for transmitting several deadly diseases to humans, such as dengue and chikungunya, potentially offering hope to millions around the world.

"This sequencing… offers great hope to our understanding of the mosquito and our ability to control it, potentially saving millions of lives in many areas of the world," -- Professor Andrea Crisanti, Editor-in-Chief of Pathogens and Global Health.

Big data battles small insect: Terabytes of mosquito pictures help enhance mosquito netting

Researchers at the University of Warwick's School of Engineering are using imaging technologies, that are normally applied to automotive engines and sprays, to image thousands of mosquitoes to help develop better netting and physical protection against the malaria spreading insect.

The University of Warwick engineers, David Towers, Natalia Angarita and Catherine Towers, are helping entomologist colleagues at the Liverpool School of Tropical Medicine, Philip McCall and Josie Parker, explore the best insecticide treatment and physical design of the protection for sleeping people in areas where mosquitoes are a problem.

In observing how mosquitoes engage with insecticide treated barriers such as netting, researchers have in the past mainly relied on recording just the final landing location, which does not give a full picture of how they approach and handle the protective barriers.

Mating with the wrong insect may cut yellow fever mosquito populations

Asian tiger mosquitoes can drive down yellow fever mosquito populations when the female chooses the wrong male with which to mate, UF/IFAS scientists say. Both insects transmit chikungunya and dengue, dangerous diseases affecting millions of people worldwide.

In a study published this month in the journal Infection, Genetics and Evolution, Post-doctoral Researcher Irka Bargielowski led a team of scientists that conducted field studies in Houston, Texas; Caracas, Venezuela; Franceville, Gabon and Singapore, Malaysia.

They studied mating between the Asian tiger and yellow fever mosquitoes and found that it in the wild, avoidance mechanisms evolved in yellow fever mosquitoes, Bargielowski said. That finding may help scientists predict population changes of the two mosquito populations.

Mosquito-repelling chemicals identified in traditional sweetgrass

BOSTON, Aug. 17, 2015 --Native North Americans have long adorned themselves and their homes with fragrant sweetgrass (Hierochloe odorata), a native plant used in traditional medicine, to repel biting insects, and mosquitoes in particular. Now, researchers report that they have identified the compounds in sweetgrass that keep these bugs at bay.

The team will describe their approach in one of more than 9,000 presentations at the 250th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society, taking place here through Thursday.

Mosquitoes and other insects remain a pesky part of everyday life in many parts of the world, and their bites are linked to a range of serious diseases, such as malaria. To add to the arsenal of insect repellents, Charles Cantrell, Ph.D., investigates the components of plants used in traditional therapies. "We found that in our search for new insect repellents, folk remedies have provided good leads."

Sweetgrass is a meadow grass that is a native to northern climates, Cantrell says. "It gives off a sweet aroma that repels mosquitoes."

Fighting mosquito resistance to insecticides

Controlling mosquitoes that carry human diseases is a global health challenge as their ability to resist insecticides now threatens efforts to prevent epidemics. Scientists from the CNRS, IRD, Université Claude Bernard Lyon 1, Université Joseph Fourier in Grenoble and Institut Pasteur in French Guiana have identified new genetic markers for mosquito resistance to insecticides, which could improve its detection in the field. This work was published in Genome Research on 23 July 2015.

The ability of mosquitoes to resist insecticides represents a serious threat to the prevention of diseases such as malaria, dengue and Chikungunya. The detection and monitoring of the resistances developed by natural mosquito populations will be essential to enabling their management in the field for as long as there are no alternatives to the use of insecticides.

Repeat infection with malaria parasites might make mosquitoes more dangerous

In malaria-endemic regions, humans are often infected repeatedly with the Plasmodium parasite, and the consequences of such multiple infections are under intense study. In contrast, little is known about possible co-infection and its consequences in the Anopheles mosquitoes that transmit the disease. A study published on July 16th in PLOS Pathogens reports that not only can individual mosquitoes accumulate infections from multiple blood feeds, but also that an existing malaria infection makes mosquitoes more susceptible to a second infection, and that infections reach higher densities when another strain is already present.

Interested in interactions between malaria parasites and their insect hosts, Laura Pollitt, from the University of Edinburgh, UK, and colleagues in the US, asked whether and how mosquitoes can be infected with different Plasmodium strains, how such heterogeneous parasites interact in the insects, and whether such interactions affect transmission of malaria to vertebrate hosts.

The researchers set up cages of female Anopheles mosquitoes and allowed them at defined times to feed on mice infected with two different Plasmodium strains. This study design allowed them to examine how the presence of a co-infecting strain affects parasites that enter the vector first and second, and to test whether co-infection impacts mosquito survival.

The mosquito smells, before it sees, a bloody feast

The itchy marks left by the punctured bite of a mosquito are more than pesky, unwelcomed mementos of a day at the lake.

These aggravating bites can also be conduits for hitchhiking pathogens to worm their way into our bodies. Mosquitoes spread malaria, dengue, yellow fever and West Nile virus, among others. As the bloodsucking insects evolve to resist our best pesticides, mosquito control may shift more to understanding how the mosquitoes find a tasty -- and unsuspecting -- human host.

A team of biologists from the University of Washington and the California Institute of Technology has cracked the cues mosquitoes use to find us. As they report in a paper published July 16 in Current Biology, the minute insects employ a razor-sharp sense of smell to tip them off that a warm-blooded meal is nearby, and then use vision and other senses to home in on the feast.

"Very little was known about what a host looks like to the mosquito and how a mosquito decides where to land and begin to feed," said UW biologist Jeff Riffell, co-author on the paper and one of three professors collaborating on these efforts.