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Bed bugs knock roaches off the list
1 Oct, 2004 By: Dr. William H. Robinson Pest Management ProfessionalIt's definitely training season. Pest management companies are checking calendars, setting dates, selecting topics and lining up speakers. There will be some new topics this year, but surely, "Biology and control of bed bugs" will be on the list — right where "Biology and control of German cockroaches" used to be. Blattella germanica has lost importance for most companies; instead, they're increasingly encountering an old friend — Cimex lectularis, the bed bug.
The German cockroach was a dependable topic for training sessions for years. We know a lot about it, so there were lots to tell. Everybody had a war story to share, and there was always an opportunity to show a picture of an infested kitchen with cockroaches in the cabinets and all over the counter (with the expected disgusted response from the audience — always fun to schedule right before the lunch break). We had graphs to show what kills and maybe even a few of those dreaded LD50 tables to explain resistance. Those were the good old days, but they're now gone.
BED BUGS HAVE BITE
What about the replacement? Does C. lectularis have what it takes to fill the big shoes of B. germanica? The answer is yes. You're going to like this bug — in the field and in the classroom. Here are just a few reasons why:
1. Even the name is good. The famous taxonomist Linneaus named the species Cimex lectularis, and he got this one right. Cimex is Latin for "bug," and lectularis means "bed." This name fits and is not difficult to say. By contrast, Linneaus was a bit politically incorrect when he named the German cockroach B. germanica. It was not really from Germany.
2. It's got street cred. There are some clever street names for the bed bug, just as there are for the German cockroach. My favorite for the bed bug is "mahogany flats" (think of their color and shape).
3. It's media-savvy. Greg Baumann, technical director for the National Pest Management Association, was on ABC and CNN talking about bed bugs this year. What's next — Letterman or maybe Saturday Night Live?
4. The bed bug is ours, and ours alone. It's completely dependent on humans to exist. There are no natural populations or reservoir habitats out there for this insect. Except for that cave in Afghanistan where a wild population was found, the only known infestations are linked to human habitats. This blood-sucking insect probably gave up feeding on birds or bats and hitched its wagon to man when we were using caves as seasonal or regular shelter. They've been with us ever since.
5. They are worldwide travelers. Bed bugs seem to be easily transported in household materials, clothing and luggage. They can tolerate a great range of temperatures and humidities, so travel in planes, boats or trains is not a problem.
6. They like to be snug as a bug. Like the German cockroach, bed bugs seem to do well when household conditions are crowded and sanitation is not what it could be. They feed on human blood, so they are usually found in or near the bedroom or where people sleep. They can also be in other rooms, however, particularly when upholstered chairs and couches are in the environment.
7. Training is similar to the German roach. Biology and habits are similar to the German cockroach, so it will be easy to reformat those training slides. See if this sounds familiar:
- there are nymphs and adult stages;
- they develop slowly;
- they are active at night;
- they prefer cracks and crevices as harborage (even baseboards);
- they often leave fecal spots behind;
- they are in residential and commercial sites;
- they seem to be able to move between rooms and apartments within buildings; and
- they are a year-round pest.
Their mating is a little unusual, but the result is the same — eggs are laid in cracks and crevices in small batches (but not in an egg case).
8. Public health is a factor. Disease transmission seems to be zero, but there is plenty of doubt and possibility with a blood feeder. Like the German cockroach (which probably doesn't transmit much either), you can mention the potential for transmitting diseases, but nothing definite.
9. Resistance is not a large problem with bed bug control. Resistance to insecticides was detected in bed bugs in the 1950s, around the same time it was detected in German cockroaches. Let's hope we don't have a return of those LD50 tables, treatment rotation plans or dire predictions of "super bed bugs" developing out there.
10. Marketing is a cinch. Bring back those stories about what will survive a nuclear bomb (now that more countries seem to have them). Remember when the German cockroach was projected to be the lone survivor of "the blast"? Well, that was never quite true. After the bomb, it will most likely be body lice and pharaoh ants. These two can withstand 225,000 rads of gamma-radiation. The bed bug can tolerate 172,000 rads. The lowly German cockroach is gone somewhere between 90,000 and 105,000 rads. Humans don't make it past a one-time exposure to about 800 rems. Of course, if humans are gone, body lice and bed bugs will follow because they have nothing to feed on. That leaves that impossible-to-control beast, then as now: the pharaoh ant.
WHY ON THE RISE?
Theories on why bed bugs are suddenly abundant usually involve increased speed in transportation and the transient habits of humans in the world today. I think we need something a little more interesting.
How about a link to the decline in German cockroaches? It was long thought that German cockroaches ate bed bugs. There were stories of cockroaches being welcomed onto sailing ships because they would eat the bed bugs that were abundant there. There were stories into the 1920s about cockroaches eating bed bugs in buildings. Could it be that when we cleaned out the German cockroaches and made a dent in the American and Oriental cockroach populations, we were helping the bed bugs survive? Sadly, there is some conclusive work to show that cockroaches really don't eat bed bugs — well, maybe a nymph or two, but this would hardly control an infestation.
Other arthropods linked to humans, such as scabies, mites and head lice, experience periodic increases and decreases in populations. Head lice may have a 15-year cycle. These cycles may be linked to fluctuating levels of susceptibility. Or it could be that typical liquid treatments for fleas, cockroaches and ants helped to keep bed bugs in check. Now that growth regulators, on-animal treatments and baits (and fewer liquid sprays) are providing control of those indoor pests, bed bugs are more successful.
So get back to training on crack-and-crevice application, careful inspections with a flashlight and a flushing agent, treating adjacent rooms and apartments, and maybe even baseboard spraying. What was old is new again
Reference
Cole, M.M., G.C. LaBrecque, and G.S. Burden. 1959. “Effects of gamma radiation on some insects affecting man.” J. Econ. Entomol. 52: 448-450.
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