Comparison of CDC 3000 and NightWatch Monitoring Devices

Tuesday January 05 2010 @ 11:20 AM Source:Bed Bug Central

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1. Physical Trap Design
The CDC 3000 is very different in appearance and design compared to the CDC 3000. It is constructed out of a very durable high density plastic and looks like a small plastic carrying case.  This allows the device to be placed out very discretely in sensitive environments and does not scream “bed bug monitor” Trapped bed bugs are contained within the unit and are not visually accessible without opening the device compared to the NightWatch unit where capture bugs are visible to anyone looking at the device.  In addition, CO2 cartridge is also contained within the device and reduces the likelihood of the removal or tampering of the cartridge by unauthorized persons.  The device also has a lock that requires a key making it completely tamper resistant.

 

The NightWatch, on the other hand is not as discrete looking. The bugs are captured in wells that are attached to the outside of device and are can be visually seen from above.  This visibility of the bugs can be viewed as a pro or a con depending upon the objectives of the monitoring program. The CO2 cylinder is also screwed in on the outside of the device and is contained within a locked compartment.

2. Method of capture

The NightWatch unit uses a classic pitfall trap design to capture the bugs.  Bugs that are attracted to the device climb ramps that are covered with a felt material and, once they reach the top they fall into trough-like well that has slippery sides which the bugs are unable to climb or escape.  This design is very simple and is highly effective.  Once the bugs are trapped the pitfall wells can be easily removed from the device, allowing the bugs to be discarded. Once the bugs are discarded the wells are reattached to the device and it is ready to catch more bugs.   The NightWatch is constructed of a smooth molded plastic that does not offer any opportunity for bed bugs to get inside of the unit. This is important, as it prevents the unit itself from becoming infested.

The CDC 3000 on the other hand requires the use of a specialized capture slide (plastic insert try that has a sticky glue) that must be purchased separately from the supplier.  The plastic capture slide not only serves as the trapping mechanism, but also has the chemical lure impregnated into the glue.  Each capture slide is intended to be used once and must be replaced with a new capture slide prior to using the monitor again.  This may seem like a disadvantage, however and advantage of this method is that capture slides can be labeled and saved as “proof” of the monitoring results.

Perhaps the greatest disadvantage of the CDC 3000 capture design is the fact that some bugs are able to enter the trap and bypass the sticky surface of the capture slide without getting captured. When this happens, the live bugs are now roaming around freely inside the device, which opens the door for introducing bed bugs into the next location that is monitored unless measures are taken to de-infest the device before using it again.  The methods that we have used to overcome this include placing the CDC 3000 device in a sealed plastic bin at the time we are removing it from the location and then heating both the plastic storage container and the CDC 3000 in a portable heat chamber (Packtite® unit) to destroy any eggs or bugs that may be inside the monitoring device.

3. Operational Time

There are significant differences between the two devices when it comes to how they actually operate.  The NightWatch unit is equipped to utilize CO2 cylinders up to 20 oz in volume that must be purchased separately and are readily available at any sporting good store where paint ball supplies are sold.  The NightWatch can operate ten hours per day for up to a week without requiring any maintenance.  The device has a digital clock that you set for the actual time of day. Once the time of day is set the internal computer will automatically turn the monitor on at 10 PM and will continue to run until 8 AM when it automatically shuts off. This on/off cycle during the bed bugs peak feeding hours will be repeated on a daily basis until the CO2 cylinder is emptied.  The ability to monitor during the nighttime hours for multiple days in a row with no maintenance required is a significant feature unique to the NightWatch.  Another nice feature of the NightWatch is that the CO2 cylinder can be removed from the device and without releasing the remaining contents of the cylinder, allowing it to be used again in the future.

The CDC 3000 operates very differently from the NightWatch.  The CDC 3000 utilizes a small 45 gram CO2 cartridge which must be purchased separately from the supplier.  Once the CO2 cartridge is screwed in and engages, the unit will begin to operate and will run for approximately 10 hours before running out of CO2.  Once the CO2 cartridge has started to release CO2 cartridge will continue to release CO2 until it is empty, thus each cylinder can only be used once.  There is no electronic timer in the CDC 3000 that turns the unit on and off.  As a result, the ten hour operational period begins the moment the CO2 cartridge is installed.  Thus in order to monitor during the nighttime hours the unit must be set late at night compared to the NightWatch which can be set at any time and will automatically turn on at 10 PM.  Setting the CDC 3000 may not be an issue for homeowners but can create logistical obstacles for pest management professionals that want to monitor during the nighttime hours at client locations.

Note:
Both the CDC 3000 and the NightWatch require electricity to operate and must be plugged into a regular 120V wall outlet.  In addition to releasing CO2, both units also have heating elements and chemical lures that are released when the unit is running.  

4. Effectiveness

Both the NightWatch and the CDC 3000 are effective at capturing bed bugs.  Research has also demonstrated that both units captured bed bugs apartment units where visual inspections by trained professionals either failed to discover bed bugs or took up to a half an hour to locate them.  In the limited field research that has been conducted to date, the CDC 3000 did catch more bugs than the NightWatch and caught bugs more often in low level infestations than the NightWatch.  Despite the fact that both units were able to capture bed bugs in low level infestations, neither unit was effective in very low infestations (no more than one bug found during extensive visual inspection by highly trained professionals).  For this reason, as with any type of monitoring device a zero trap capture cannot be interpreted as “no bugs” present.

5. Cost Comparison (based upon the pricing at the time this was written -12/2009)

The NightWatch unit retails for approximately $600.  Included in this cost is the actual device, reusable pitfall ramps, 4 chemical lures (each lure provides 7 days of use) and an instructional guide.  The only item that needs to be purchased separately is the CO2 cylinder which can be purchased at any sporting goods store as well as stores like Wal-Mart, Target or any other store that sells paint ball supplies.  The cylinders vary in cost depending upon the size but will typically retail for $30.00 or less.  Once the cylinder is purchased they can be refilled at the store for approximately $6.00 or less.  Additional chemical lures can also be purchased in packs of four at an approximate retail cost of $40.00

The CDC 3000 unit retails for approximately $1000.00. Included in this cost is the actual device, 3 single use CO2 cartridges, 3 single use capture slides, and the instructional guide.  Additional CO2 cartridges and capture slides must be purchase from the CDC 3000 supplier and with a minimum quantity of 25 required.  The retail cost for 25 CO2 cartridges is $250 and $187.50 for 25 capture slides, however the cost for each decreases with volume purchases.

Reminder: It is important to not that while monitoring tools and methods have certainly improved; no tool or method exists that is completely reliable in detecting bed bugs. For this reason, regardless of what method or device implemented, the failure to identify bugs cannot be used as an indicator that no bugs are present. Low level infestations can still escape detection regardless of the detection methods implemented.