15 Jan FMC verify bed bug detector verses interceptors. A comparison

In a recent blog I noted that a commercial Co2 trap  (FMC verify fed bug detector) performed poorly compared to my modified glue board traps placed under bed legs.  I opened the verify detector and found that all the components had been properly activated.     I decided to test this Co2 device in another setting.  I purchased a second  brand new FMC verify bed bug detector and activated both the lure component and the Co2 component.  I took both devices (“old”  and new) and took them to a large severely infested rooming house that was being prepared  for treatment by the local Bug N Scrub team.   All experiments were performed before the exterminator started work.   I performed 3 separate experiments  as follows:


EXPERIMENT 1  (24 hour test)

Suite A

I placed one interceptor and the new FMC trap 3 feet away from the bed along an inside wall.  The traps were approximately 10 inches apart.  The results were:

Interceptor 2

New FMC   14


Suite B

I placed one interceptor and the old FMC trap 7 feet away from the bed behind a dresser.  The traps were approximately 10 inches apart.    The results were:

Interceptor 16

Old FMC  7


EXPERIMENT 2  (2.5 day test)

I then swapped the old and new FMC traps and repeated the test over the weekend (2.5 days)  The results were  as follows:

Suite A

interceptor 19

Old FMC  13


Suite B

interceptor 6

New FMC   7


EXPERIMENT  3 (24 hours)

This time the FMC traps were placed at the head of the bed against the wall.  The beds were isolated with an interceptor look-a-like device called the “defender.”  We used these devices because they were provided by Bug-N-Scrub for free.  The two devices are roughly comparable with similar colour, height, texture, angle of ascent, sharp pitfall lip,  etc.    The traps were examined 24 hours later and the results are as follows:

Suite A

4 interceptors 7+7+7+13= 34 bugs trapped

Old FMC  11 bugs trapped


Suite B

4 interceptors 38+0+12+6= 56 bugs trapped

New FMC 6 bugs trapped



Experiment 1 and 2 showed mixed results.  In one case the new FMC outperformed a random interceptor by a factor of 7 (14 to 2).   Impressive.   In one other setting  it appeared the random interceptor and the FMC were roughly comparable.  And in 2 of the cases  (both the old FMC)  the random  interceptor actually outperformed the FMC.    Hmmmm.

I did note that the bugs trapped in both FMC units (old and new) attempted to feed through the Co2 and lure  holes.  The bugs stuck their entire heads into these little holes suggesting that the devices were releasing attractive substances.  (or perhaps they were attempting to hide???? Another study required – sigh.  There is so much we do not know) .  Also some of the bugs harboured on the side of the FMC in a manner similar to bugs harbouring on the side of an interceptor when in use.  Some bed bugs are repelled by pitfall  traps and harbour on the edges of the traps. This last observation colours my view that the bugs sticking their heads in the holes is due to the attractants.   Both these observations suggest the devices were functioning.

In terms of random catching the interceptor enjoyed a substantial advantage because its pitfall was closer to the floor and the approach was a preferred substrate (fuzzy tape).  If I put a random 4 inch tall plastic pitfall trap in the room I would not catch many bugs.  Therefore I would assume that the FMC trap was  functioning.  If it was not functioning it would have caught even fewer bugs.

Due to the mixed results a larger study would be required to determine the effectiveness of the FMC in a random placement in an occupied room.

Experiment 3 showed that the FMC was completely outclassed by the interceptor/defender traps.  The interceptor/defenders caught 90 bugs while the FMCs caught 17.  As such my first impression of the FMC was correct.  Interceptors or glue boards under the bed legs will capture  more bugs (5 times more in this study)  than an artificial bait trap.

I suspect the FMC trap would prove superior in empty suites.  Perhaps that is where it will shine.