Irradiated, sterile flies dropped over seaports and agricultural areas to mate with unsuspecting females save food crops and millions of dollars in prevented infestations and the ensuing eradication efforts.
But blasting these secret-suitor insects with radiation via electron beams, X-rays or gamma-rays, tends to make them weaker than typical males — and not so appealing to females as possible mates.
UF/IFAS photo by Marisol Amador
University of Florida insect physiologist Daniel Hahn displays the type of flies used to protect valued crops, in what is known as the sterile insect technique.
What sterile-insect operations need, says University of Florida insect physiologist Daniel Hahn, is the insect world’s version of George Clooney: 52 years old, gray-haired and still dazzling the ladies. Hahn, an associate professor with UF’s Institute of Food and Agricultural Sciences, and his former postdoctoral associate, Giancarlo López-Martínez, now an assistant professor at New Mexico State University, describe in research publications this month and last, that sterilizing insects in a low-oxygen environment helps create suitors who more closely resemble the suave Clooney than do those sterilized in a normal-oxygen environment.
“Our males (insects) are not only more sexually competitive, they are maintaining their sexual competitiveness and their virility, into old age,” Hahn said, “and that has the potential to make them much better biological control agents.”
The sterile insect technique, or SIT, has been used for decades and is considered a much preferable alternative to spraying pesticides over urban or suburban areas near major ports. In this biological control method, large numbers of sterile, male insects are released to compete with wild males for the attention of invasive wild females.
A female duped into accepting a sterile male would then find herself without offspring, thus trimming the population and its threat to the state’s important agricultural crops. The technique has been used effectively against the Mediterranean fruit fly, called the Medfly, and the cattle-infesting screw-worm fly, among others.
Florida spends roughly $6 million a year using SIT to prevent Mediterranean fruit fly infestations, while California spends about $17 million a year. Because of the inherent dangers in importing even one Mediterranean fruit fly into the state, in their recent studies, López-Martínez and Hahn investigated the physiological effects of applying low-oxygen treatments prior to and during irradiation sterilization on two other plant pests: the Caribbean fruit fly and the invasive cactus moth.
The “low-oxygen effect” has been known for decades, but the physiological basis for it had never been rigorously tested or analyzed, Hahn said. They suspected, and found, that under the low-oxygen conditions, the insects’ cells would produce antioxidants that can help better protect them from the off-target radiation damage.
Some operations that rear and sterilize insects, such as one in Guatemala that produces many of the sterile medflies dropped over Florida’s major ports roughly every seven days, do employ low-oxygen conditions, called hypoxia or anoxia. But many others don’t, he said, including those who rear and sterilize the cactus moth.
The reseachers found using a low-oxygen environment during sterilization boosted the sterile males’ longevity as well as their ability to attract and successfully mate. They found that the positive effects of low-oxygen treatments even extended into their ‘old age’ – in the insects’ case, about 30 days under cushy laboratory conditions.
Treatments that both improve the sexual performance of sterile males and maintain high performance longer in older males can substantially increase the effectiveness and decrease the economic costs of SIT programs, Hahn said.
The January paper was published by PLoS One, and the February paper in the Journal of Economic Entomology. Hahn and López-Martínez were joined as authors of that paper by James Carpenter of the USDA’s Agricultural Research Service in Tifton, Ga., and Stephen Hight of the USDA-ARS at Florida A&M University in Tallahassee.
Mickie Anderson | newswise
Open-access article on Mexican bean beetles offers control tips
03.02.2016 | Entomological Society of America
Improved harvest for small farms thanks to naturally cloned crops
29.01.2016 | Universität Zürich
Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.
The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
12.02.2016 | Event News
09.02.2016 | Event News
02.02.2016 | Event News
12.02.2016 | Physics and Astronomy
12.02.2016 | Life Sciences
12.02.2016 | Medical Engineering