As promised, this week I'll continue to share my notes from the National Conference on Urban Entomology (NCUE). I've categorized the 28 presentations on bed bugs under the topics of:
- rearing bed bugs,
- biology and behavior,
- treatment protocols,
- heat treatments,
- pesticides, and
- other bed bug presentations.
This week I'll cover 7 presentations that fell under the first two topics. Knowing basic information about bed bugs helps us find their weak points and design treatment strategies that work.
Rearing bed bugs
For a pest that seems so ready to infest, bed bugs are awfully hard to keep happy in a lab. A good study takes hundreds of bugs, so learning how to rear them right is important to research. Plus, you can learn a bit about a bug by essentially keeping it as a pet.
Four presentations covered bed bug rearing:
- A novel method for artificially feeding bed bug (Ronda Hamm from Dow Agrosciences LLC)
- Lessons learned in bed bug rearing (Joshua Bryant from Ohio State University)
- Optimization of an in vitro system for rearing bed bugs with notes on their development on different host bloods (Alvaro Romero from New Mexico State University)
- Assessing bed bug control programs using mock environments (Kyle Jordan from BASF Pest Control Solutions)
Lessons learned from these researchers:
- A practical rearing system uses a simple heating pad or hot plate to warm containers of blood. Bed bugs access the blood by feeding through a membrane. The jars holding the colonies are placed upside-down onto the blood source membrane. Bed bugs crawl down (or are tapped to the bottom) to feed on this system. It’s easy to set up and if the membrane breaks, the bugs don’t drown.
- Bed bug colonies do best (stay alive and lay eggs) on chicken blood. Rabbit blood came in second followed by bovine. Human blood was not evaluated. Researchers don't use human blood to rear bed bugs that will be used for peer-reviewed studies. It's really hard to get permission to use humans as food from the powers-that-be so researchers buy blood. My bugs are used only for teaching purposes...and my blood is free.
- Chicken blood will stay good for up to three weeks in the refrigerator.
- Those trying to maintain colonies must be wary of their blood sources because the shipped blood can contain chemicals from animal medication or pesticide treatment of rearing facilities—it’s hard to know about your source so don’t feed all your colonies on one batch of blood.
- It takes about 27 days from when the female feeds before laying an egg to get to the 5th instar (the last stage before adult).
- Building a mock bedroom and trying to infest it with bed bugs is not as simple as you may think! Perhaps the lab colonies have lost some of their natural behavior.
Bed Bug Biology and Behavior
Effect of various blood alcohol concentrations on bed bugs (Ralph Narain from University of Nebraska)
You read right—this research looked at what bed bugs think about a night out at the bar! As fun as the study set up sounds, no alcohol was consumed by researchers. They fed bugs on blood that had varying levels of alcohol and observed the results. In short, bed bugs are not alcoholics. They consumed less blood if there was alcohol in it and went on to produce fewer eggs.
Bed bug egg morphology (Brittany Delong from Virginia Tech)
Many treatment failures are blamed on bed bug eggs. Yet we don’t know a lot about the make-up of the eggs. Delong is trying to remedy that by taking high magnification images of the 1mm long life stage. In the process of her research, she has gotten to know the bed bug mothers quite well. She sees them beginning to lay eggs 24 hours after feeding and continuing to lay eggs for 11 days. A well-fed bed bug female can produce 147 eggs in a lifetime.
Susceptibility of multiple field collected strains of bed bugs to selected insecticides (Sumiko De La Vega from Sierra Research Laboratories)
The major finding from De La Vega’s research was not about insecticides, but about the bed bugs. She found that the resistance levels of her colonies went down after two to four years of being in colony without any pesticide exposure. This complicates pesticide research done with “field” strains because researchers can’t count on resistance levels staying the same between studies. Just when we thought we had it figured out...another wrench in the study of bed bugs!
For those of you who attended the "Taking Control of Bed Bug Treatments" webinar, I am sorry to say I am not going to have the recording posted this week. They will be posted next week and it will tie in nicely with the treatment protocols presentations from NCUE. I have the files ready to go, but our website guru isn't in the office and Molly Stedfast, my co-presenter, is riding a bike for a few days alongside Phil Cooper of BedBug Central. Phil is riding across the US for MS. Check out www.philacrossamerica.com to support the cause!