Important Considerations for Cockroach Monitoring in Schools and Commercial Accounts

Bobby Corrigan, PhD
IPM Specialist
RMC Pest Management Consulting

Two Important Points relative to Monitoring and IPM in Schools:

1. Monitoring is the single most identifiable practice you can perform to put your program into the IPM Mode.
   
   
2. 'Consistent, repeated use of sampling procedures to monitor changes in German cockroach populations should be considered an important and fundamental part of a control program.' (J.M. Owens, 1995).

Why Monitor?

1. To detect the presence of pests.
   
   
2. To detect changes in the pest population (before and after your program).
   
   
3. To determine the spatial disribution of the cockroaches. This will allow you to maximize efficiency of baiting effort by determining optimal baiting locations.
   
   
4. To determine any movement patterns of the pest (due to equipment changes, harborage disturbance, etc.)

On The Job Tips For Monitoring In Commercial Accounts

1. When trap counts are repeatedly zero, but visual complaints continue, conduct a trap shuffle. Move traps into other suspected micro and macro zones conducive to cockroaches.
   
   
2. Trap monitors cannot remove a significant portion of a German cockroach population in the field when used in reasonable numbers (i.e., traps do not control cockroaches). Even with massive trapping programs, you will only trap a maximum of 30% or less of the population.
   
   
3. When attempting to demonstrate before and after results of German cockroach IPM programs, (i.e., “yes, we did our job”) use monitors. Note that monitor traps must have the exact same placement before and after the control program.
   
   
4. Research has shown repeatedly that traps placed less than one inch away from walls, and vertical surfaces captured 50% less roaches than those placed flush against walls. This is due to cockroaches surface-loving behavior (thigmotactile responses). So go for the corners of drawers, cabinets and walls, and equipment.
   
   
5. Always sample at room heights that include low, medium, and high (e.g., suspended ceilings).
   
   
6. Traps are biased for adults (nymphs tend to escape).
   
   
7. Trapping of ONLY 1st and 2nd instars indicates that a capsule was deposited nearby. Trapping of several size nymphs indicates that a population harborage area is nearby.
   
   
8. How long can cockroaches live on the traps?

   - Adults: 7-10 days
   - Nymphs: 2-4 days
   

9. Zero counts on sticky traps for short periods (24 hours) alone does not confirm that cockroaches are absent. However, if traps that are well placed in pest vulnerable areas (PVAs) for prolonged periods are consistently empty, this is a reasonable indicator of no cockroaches, or a very minor infestation level.
   
   
10. Leave a few monitors with client for them to be familiar with the traps and how they work.
    
    
11. A reasonable number of traps placed out in PVAs for 24 hours prior to a professional’s visit can give a good indication of population distribution and the relative size (minor, moderate or severe) of the infestation. A 24-hour count will provide you with an estimate of about < 5% of the population.

The Golden Rules For On-the-job Use Of Cockroach Monitors

1. Use sufficient numbers.
   
   
2. Install into good roach habitats: - Macro locations: Think “the tropics”: warmth + water + good harborage (wood/cardboard clutter) + near food. - Micro locations: Cockroaches love Corners! Install traps in corners of drawers, cabinets, equipment and walls. 3. Keep records of the number of cockroaches or other pest species trapped. Blank Monitoring Log Example Monitoring Log 4. Use station markers to help you remember trap placement. The chance of destruction of traps, employee theft, or of traps being moved or removed is significant. Replace traps that have been removed and try to educate the client about the importance of the monitoring traps.

How Many Traps Should You Use?

1. There is no magic number or formula. The number of monitoring stations will depend upon the level of population estimate desired by the pest control professional and client.
   
   
2. When you want an on-the-job profile of the population:

   For initial inspections and high data return situations:

   • A commercial kitchen storage room = 25 - 40 traps.
     
     
   • Reduce traps as needed per level of infestation.
     
     
   • Maintain permanent monitors in the PVAs (think Tropics); about 10 traps per kitchen.
     
     

   For office complexes:

   • One monitor per computer station.
     
     
   • Monitors within employee desks with snacks.
     
     
   • Four monitors per coffee station.
     
     

Types Of Monitoring Programs In School Kitchens and other Rooms with Equipment:

1. Inspection with flashlight only (live roaches, frass, body parts).


2. Inspection with flashlight and non-residual flushing agents (only when students and personnel are absent, and immediate cockroach elimination is essential).


3. Installation and record keeping of sticky trap counts.
• Sticky traps will capture more cockroaches than can be counted visually, or sampled by the use of flushing agents.
• However: Zero counts on sticky traps alone does not confirm that cockroaches are absent.

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