We have all suffered the irritation of being the food source for hungry mosquitoes. While it is generally well known that female mosquitoes need a meal of blood before laying their eggs, less has been written about their appetite for sweet snacks between meals.
It is this diet of "sweets" – derived from nectar from flowers and nectaries on plant leaves and stems - that provide mosquitoes with their persistent energy.
Schlein and his co-researcher, Günter Müller, in the Department of Parasitology at the Hebrew University-Hadassah Medical School's Kuvin Center for the Study of Infectious and Tropical Diseases, decided to exploit the mosquitoes' thirst for sweets to bring about their demise - by spraying acacia trees with a sugar solution that had been spiked with the oral insecticide Spinosad.
The experiment was carried out in an oasis in the southern desert region in Israel where some scattered trees flower most of the year, including during a long, dry and otherwise flowerless season. Schlein assumed that in the absence of other sugar sources nectar-searching mosquitoes would be attracted to these plants.
The oasis was chosen for its isolated mosquito population, so that the experiment could be carried out effectively without influx and exchange of mosquitoes from neighboring areas.
Sucrose solution spiked with the oral insecticide Spinosad was sprayed on acacia trees in the oasis. The spraying of insecticide had the effect of eliminating almost the entire mosquito population in the oasis. The few mosquitoes that were trapped after spraying were thought to be newly emerging adults, and cumulative population growth was prevented by continuous effect of the insecticide. Thus, the oasis was completely depleted of its mosquito population.
Schlein says that in a desert area, in the dry season, the flowers of sparse perennial trees or bushes are key elements in the habitat of adult mosquitoes, since they are the only source of sugar. In dry areas, the shortage of sugar sources may even limit the life span of mosquitoes and thus decrease their ability to transmit diseases. Even when a large variety of flowers is available, the number of sugar sources is limited by the preferences of the mosquitoes. For example, among 77 flowering plants in Wisconsin, mosquitoes concentrated on four dominant ones.
Schlein believes that blossoms that are nectar-feeding centers may be used for efficient mosquito-control, if sprayed with the Spinosad-sugar solution bait. Spinosad is an environmental "reduced-risk" oral insecticide that has little effect on several insect groups, and has low toxicity to birds and mammals.
Places that might be suitable for using floral centers for control of mosquitoes are desert and savannah regions, particularly in sub-Saharan Africa, where the burden of malaria is increasing due to environmental changes, drug resistance and mosquito resistance to conventional insecticides. These areas include large-scale irrigation projects in arid and semi-arid areas that cover nearly half of the arable land in Africa and similar projects in the desert in Pakistan. In these regions, irrigated crops, such as rice, are not a source of nectar for adult mosquitoes, while sugar meals are scarce in the surrounding arid areas.
Therefore, the planting of mosquito-attracting trees or bushes in suitable habitats, sprayed with oral insecticide, could provide a relatively easy and cheap way to supplement the limited arsenal against mosquitoes – and the fight against malaria.
Jerry Barach | alfa
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy