AmericanAcademy of Entomological Sciences
Knowledge, Experience, Commitment
July 5, 2010
Mr. Rodger Williams
Manager
Applied Science Labs
PO Box835
Carmichael, CA95609 0385
RE: ASL Residual Tests with Bed Bugs Cimex lectularius
Report:ASL VX8807032010 and Invoice.
Introduction: Applied Science Labs contracted American Academy Entomological Sciences to observe and record the results of compound VX88. This portion deals with the residual efficacy on a specific substrate labeled as ASL-A using Cimex lectularius as the bioassay organism. The tests were conducted using the C. lectularius strain from a laboratory on the east coast two consecutive days to establish mortality/morbidity of the effect of VX88 after it was applied to substrate material labeled as ASL-A and left until material was dry to the touch or perceived by visual observation as considered dry. Results will be discussed in section under Results and Discussion.
Materials and Methods: A colony of Cimex lectularuiswas obtained from a laboratory and shipped by next day air to a secure location in Jackson, MS which wasto be used while conducting the experiments using bed bugs without contamination to them or infesting the environment. Nine Fisherbrand Sterile 100 mm x 15 mm Polystyrene Petri Dishes, model number 0875712 were used and numbered 1-7 and two as “C” for controls. ASL supplied AAES with what looked like a miniature mattress with a fabric cover; the cover was labeled as ASL-A which was cut into nine (9) circular segments to be placed into the bottom of the Petri dishes.
Note: The material used from the mattress and labeled as ASL-A is of slightly different makeup from the bottom piece then the top piece that the circular segments were cut. Therefore, researcher mixed them together in a paper bag and randomly selected nine (9) pieces of the substrate fabric for the test.
The seven (7) pieces were placed on a plastic coated board, a packet of VX88 was mixed to label directions in a one gallon container and enough tap water added to measure one (1) gallon of material and agitated for approximately three (3) minutes. The seven (7) test fabric materials were sprayed using a pass time of four (4) feet per second with the nozzle of the pump container at the fan setting (all test substrate fabric sections were in the same orientation as they were on the miniature mattress before cut). Two (2) circular pieces were not sprayed as they were used as the controls. The test fabrics were not moved from the plastic coated board until completely dry within three (3) hours. Once drying was completed, each section was randomly selected and placed usingforceps into one of the numbered 1-7 Petri dishes and two (2) “C” Petri dishes. The container of bed bugs was refrigerated for 4.5 minutes to cool and slow their movements until they could be placed in each Petri dish. Five (5) adult bed bugs were placed into each Petri dish along with 3-5 various nymph bed bugs.
Note: The first bed bug picked up with forceps was damaged and thereafter a tiny art paint brush was used to transport the bed bugs from the container to each Petri dish. In doing so the brush would pick up nymphs. All nine (9) Petri dishes were placed in a plastic container 18’ x 12’ x 12’ where the top two (2) inches were applied with petroleum jelly. The entire container was then placed in a rubber container 24’ x 24’ by 18’ with 0.5 inches of tap water on the bottom as a safeguard should any bed bugs were to escape the Petri dishes.
The mortality/morbidity was recorded every five (5) minutes for three (3) hours.
Results and Discussion: Mortality of bed bugs was recorded in Petri dishes 1, 2, 3, 5, 6 and 7 at 11, 33, 11, 33, 33, and 11 % respectively and zero (0) mortality in number four (4). One (1) dead bed bug was recorded in control number “C” nine (9) which was due to being pinched by the forceps. After three (3) hours the test was terminated. From previous experience with VX88 these results of mortality efficacy was lower than would be expected.
I reexamined the protocol for any incongruence that may have occurred to reduce the percent mortality in the bed bugs. After inspecting the substrate fabric materials I realized that there was not much residual VX88 to the touch as was thought would be applied at the pass rate of four (4) feet per second. Therefore I removed all the bed bugs in each Petri dish, disposed of them, rinsed the substrate fabric in tap water and let dry to touch. I retreated seven (7) of the substrate fabrics with the pass rate of one (1) foot per second depositing approximately slightly less than fifty (50) percent more residual material. Five (5) adult bed bugs were added to each numbered Petri dish along with 3-5 nymphs. Results were recorded every 30 minutes for three (3) hours and then every three (3) hours for the remaining twenty-one (21) hours. One hundred (100) % mortality was observed and recorded in Petri dishes numbered 1-7 after twenty-two (22) hours with zero (0) mortality in controls labeled C1 and C2.
The test was concluded two (2) days after initiation; all remaining bed bugs were disposed of by spraying with the VX88. Mortality was observed and recorded in less than three (3) minutes for the nymphs and less than 5 minutes for adults.
Sincerely,
Jeffrey K. Brown, Ph.D., R.P.E., B.C.E.
AmericanAcademy of Entomological Sciences
850.499.7961
Enclosure: Invoice