A preliminary evaluation of spraying insect repellant (DEET) on a bed bug infested bed in multi family settings.

About 1 month ago a fellow who lives on the first floor of my apartment block discovered bed bugs in his bed and sprayed DEET on the bugs (we will call this infestation A). I recognized the danger of this treatment and took the opportunity to do my annual bed bug check a little early. I inspected all 36 suites and found zero evidence of bed bugs on the second, third or fourth floors. The first floor had one single bug found relatively close to the DEET sprayer (infestation B) with a presentation suggesting the DEET sprayer was responsible.  The beds and couches for infestation B were immediately heat sterilized and the bed isolated with glueboard/interceptor combo traps.  Approximately 30 days after the DEET spraying I did a complete inspection of the main floor and discovered another single dead  bug in an interceptor in a suite 2 suites away from the DEET sprayer (infestation C). No other evidence of bed bugs was noted suggesting the DEET sprayer was again responsible. We will continue monitoring.

The DEET sprayer (infestation A) had most of the furniture heat treated and the bed and couches were isolated with traps. The couches received only interceptors while the bed received an interceptor/glue board combo trap. Inspections at the two week mark revealed zero bugs in the couch traps but 31 bugs in the bed leg traps. These traps were replaced and checked again two weeks later and 7 more bugs were noted. Again the presentation was very odd. The infestation did not appear to be large enough to warrant catching 38 bugs on the glue boards but these bugs were indeed caught. Furthermore the bugs usually are caught at the head of the bed and this time a significant portion of bugs were caught at the foot of the bed. This is an odd presentation suggesting a significant scattering throughout the bed room.

It appears my initial fears were warranted. DEET appeared to push the bugs out the door and down the hallway more than 60 feet. The suites directly beside the infested suite and directly across the hall appeared to be unaffected. As such it appears that DEET scatters bugs more thoroughly than RAID. Keep in mind this is a single small study and my results may not always be repeated. But if you do not pay attention to the little stuff you never see broader patterns emerging. Hopefully I never see a repeat of the DEET sprayer.


update on May 30, 2012

The entire main floor was checked for bed bugs today and there were no bugs found in any suite.  Infestation  C, noted to have one dead bug in an interceptor  previously, had the beds and couch heat sterilized but there was still no other sign of bugs.  Even the original deet spraying suite has now gone 28 days with zero bugs caught during that time.  Please note that the only chemicals applied in this setting was three applications to the public hallway baseboards.  The suites had only furniture heating and mechanical trapping as a control measure.   I could easily apply a standard course of insecticide  in the suites but I am hoping to treat this infestation in an experimental fashion.

We do need to go back to one suite nearest the deet sprayer  (suite B) that had one bug discovered on the bed and keep checking as the tenant, for whatever reason, decided that the couch was more comfortable than the bed.  Despite being explicitly told to sleep on the nice heat sterilized  bed  the tenant slept on the couch.  The tenant also removed the mechanical traps from the bed.  Sigh!!!!    As such my mechanical trapping provision for this suite was useless.  Because the infestation was so small I did not put interceptors under the couches.  We will continue monitoring.  I might have to reheat the furniture for peace of mind – we will see.   For general information the tenant in suite B did state that a bed bug had been observed on the curtains and the bug was destroyed and  discarded without allowing me to properly identify the bug.  Given the infestation is so small I really doubt that the bug was a bed bug.  Once again I left instructions with this tenant to contact me for all pest/insect related matters.  I hope the the tenant understood.   Tenant relations can sometimes be quite frustrating.

Also a suite that has had no bugs found to date also failed to use their interceptors properly (suite D)  I need to go and re educate these folks and continue monitoring.  All other suites had decent cooperation.  I will continue updating.

Update on June 9, 2012

We arranged to have the furniture in suite B  resterilized today for peace of mind.   The tenant has now been sleeping on the bed for the last 10 days and the glueboard/interceptor traps contain no bed bugs.   No bugs were observed on the couches either.   That is excellent news.    When the furniture is replaced the bed and two couches will all receive glueboard/interceptor traps.  This will allow me to better monitor this suite even if compliance is lacking.

We also carefully checked suite D for bugs and found no evidence of infestation.  We installed interceptors correctly and will continue monitoring.


Update on June 30, 2012

Suite A bought a house and moved out this month.  I took the opportunity to check the suite on his last day  and found no activity.  That means 2 months with zero bugs.  Interestingly enough  all the traps in the suite disappeared  when he moved out – must have thought they were valuable!!


Update on July 16, 2012

Inspected entire main floor and found zero bugs.  That makes 10 consecutive weeks of zero bugs for the entire main floor.  I consider that to be bug free.    Please note that all three infested suites were successfully treated for bed bugs with nothing more than heat sterilizing the furniture and and placing glue board traps under the bed legs.  The largest amount of work in the procedure was educating the tenants about the necessity to isolate the bed and a great deal of monitoring.  Keep in mind this procedure does not necessarily work in all settings.   For example, if a bedroom is found to have bed bugs and is subsequently abandoned this procedure will not work.  The bugs will simply hide in  the baseboards until a host arrives.  Chemical applications are still valuable – I just wanted to see if I could get rid rid of the bugs without chemicals.  This blog outlined that effort.


Update on May 6, 2013

Inspected entire building  for bed bugs and found one infestation on the third floor.  All suites on the first and second floors, neighbouring the  main floor suite infested by the Deet sprayer 1 year ago, are bug free.  As such the chemical free approach to addressing bed bugs has, in this instance, been completely validated.

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