Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Use Bed Bugs' Own Chemistry Against Them

05.06.2009
Scientists here have determined that combining bed bugs' own chemical signals with a common insect control agent makes that treatment more effective at killing the bugs.

The researchers found that stirring up the bed bugs by spraying their environment with synthetic versions of their alarm pheromones makes them more likely to walk through agents called desiccant dusts, which kill the bugs by making them highly susceptible to dehydration.

A blend of two pheromones applied in concert with a silica gel desiccant dust proved to be the most lethal combination.

In the past decade, bed bugs have become an increasing problem in industries ranging from agriculture and housing to travel and hospitality, so much so that the Environmental Protection Agency hosted a National Bed Bug Summit in April of this year.

The species, Cimes lectularius, also is developing resistance to the insecticides approved to spray infested areas, treatments that belong to a group of compounds called pyrethroids.

Desiccant dusts that are sprinkled in infested areas, however, are among the oldest forms of insect control and are still considered effective killers as long as the bugs walk through them.

"Once we put the alarm pheromone in the places bed bugs hide, boom, they instantly started moving around and moving through the desiccant dust," said Joshua Benoit, lead author of the study and a doctoral candidate in entomology studying under David Denlinger at Ohio State University.

"Consistently, the addition of a pheromone blend to desiccant dust was more effective than adding either chemical by itself or by using desiccant dust alone."

The research is published in the current issue of the Journal of Medical Entomology.

The two bed bug alarm pheromone ingredients are known as (E)-2-hexenal and (E)-2-octenal. When bed bugs are disturbed or excited, they secrete these two pheromones and tend to want to move around.

While some pheromones are known to attract species for reproductive purposes, these particular pheromones act more as a repellent, Benoit explained.

"These pheromones also can be bought from any chemical company. They're well-established chemicals, are easy to make in the lab, and are readily available," he said.

Two types of desiccant dusts were used in the experiments: diatomaceous earth, a naturally occurring, chalky substance, and a compound called Dri-die, made from a silica gel. Desiccant dusts are designed to disturb the bed bugs' cuticle, particularly the waxy outer layer on insects that allows bugs to stay hydrated. Without the waxy protection, insects are more prone to dry up and die.

The researchers first tested the chemical combination on five bed bugs at a time for 10-minute exposures in petri dishes. They tested both types of desiccant dusts as well as each pheromone component alone and in a blend more typical of natural secretion.

Bed bugs exposed to Dri-die and a blend of pheromones lost water at a much faster rate than did bed bugs treated with the desiccant dust alone. The scientists found that bed bugs exposed to Dri-die alone lost 21 percent more water than untreated control bugs. Water loss nearly doubled with either (E)-2-hexenal or (E)-2-octenal applied alone and tripled with a blend of both pheromones.

Young bed bugs exposed to the combination died in about a day, three days earlier than control bed bugs. Adult female bed bugs exposed to the combination survived for about 6 1/2 days, compared to females exposed only to the desiccant dust, which lived for an average of 17 days.

In petri dish tests, the scientists found that the combined treatments using Dri-die consistently worked better than those using diatomaceous earth at generating rapid water loss in the bed bugs.

Turning to a more natural setting for bed bugs, the researchers set up a small plastic container in which a folded piece of paper offered bed bugs a place to hide. Bed bugs tend to stay hidden in wall and floor cracks, moldings or mattresses by day and feed on human or animal blood at night. The researchers created this experimental habitat to see if alarm pheromones would bring bed bugs out of hiding.

After the bed bugs stopped moving within the paper, called a harborage, the scientists applied the desiccant dust followed by the alarm pheromone. They used the most effective blend of pheromones as determined in the petri dish experiments, as well as Dri-die, the more effective of the two desiccant dusts.

All of the bed bugs came out of hiding within five minutes of the application of the alarm pheromones, Benoit said. And the combination of a blend of pheromones and Dri-die reduced survival by 50 percent of both young and adult bed bugs, he said. At least half the young bed bugs were dead within 10 days, and about 60 percent of adult female bed bugs died within 40 days.

"Desiccant dust is messy, but it's not toxic, so it can be used in agricultural settings, such as chicken coops, where bed bugs can be a big problem," Benoit said. The dust method also can be used in housing, where it would be sprinkled on carpet and eventually vacuumed.

These results were achieved in small areas, but Benoit and colleagues hope the technique could also be applied to large environments infested with bed bugs. Benoit is reluctant to suggest the use of desiccant dusts with alarm pheromones until additional experiments are conducted.

"Before companies start selling desiccant dusts laced with alarm pheromones, more tests need to be carried out in room-sized arenas to determine any possible negative effects," Benoit said. Even so, the researchers believe the use of alarm pheromones could increase the effectiveness of desiccant dusts and other kinds of residual insecticides used to kill bed bugs as well.

Benoit noted that repeated use of spray pesticides to which bed bugs are resistant boosts the survival of bed bugs with that resistance, forcing the use of higher and higher concentrations of toxic chemicals to eradicate the insects.

"We think that rather than pursue completely new pesticides, it's better to use old pesticides in new ways," he said.

This research was supported by a grant from the National Institute of Allergy and Infectious Diseases and an Ohio Agricultural Research and Development Center Director's Fellowship to Benoit.

The study's co-authors are Seth Phillips and David Denlinger of Ohio State's Department of Entomology, and Travis Croxall, Brady Christensen and Jay Yoder of Wittenberg University's Department of Biology.

NOTE: An image is available at:
http://researchnews.osu.edu/archive/bedbugalarm.htm
Contact: Joshua Benoit, (614) 247-5093; benoit.8@osu.edu (E-mail is the best way to contact Benoit.)

Emily Caldwell | Newswise Science News
Further information:
http://www.osu.edu

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>