Baiting And Fogging For Cockroach Control

Q: We are wondering if we could use baiting and fogging for German cockroach control.

Our idea is to bait within pieces of equipment and then fog the room the equipment is in. We think the roaches within the equipment will feed on the bait and that the fog will kill any of those out in open areas. Does this sound reasonable? (W.M.)

A: I am trying to imagine when such a strategy might be necessary; generally speaking, when you use baits for German cockroach control indoors, you should use baits and baits alone. The only exception to this might be the use of an insect growth regulator prior to the application of baits in an attempt to stimulate feeding by members of the population, which may not be actively seeking food at the time of baiting.

I do not believe that the use of non-residual products, such as pyrethrin, would ever be appropriate as an ultra-low volume or fogging treatment at the same time baits are applied. It is true that little or none of the ULV penetrates into cracks, crevices or voids when applied strictly as a volumetric treatment and would probably not adversely affect baits placed deep within pieces of equipment or other cracks and crevices. However, I cannot envision a situation where that treatment approach would be necessary.

CONTROL AMPHIPODS WITH
A PERIMETER TREATMENT

Q: We have had a lot of calls this year to control amphipods. Customers usually find them dead inside their homes and want something done about them.

We have been telling our customers that they are harmless and they should just simply clean them up and forget about the problem, as it will not affect them or their home. However, many of our customers want us to treat with something. What do you recommend? (B.L.)

A: You’re absolutely right that in 99% of the cases there is nothing that needs to be done when people find amphipods in their home. They cannot survive in the indoor environment and typically will die and turn a shade of red or pink, which is one of the most notable diagnostic characteristics of this creature.

Outdoors these animals live in and under mulch in flowerbeds. They require a fairly high and stable level of moisture to survive. Homes with automatic watering systems in flowerbeds and plantings will, on occasion, build up large numbers of these crustaceans. Both excessive moisture and draught conditions will force amphipods to move into structures in search of a more suitable climate.

Most insecticides labeled for exterior/perimeter treatment are effective against amphipods. Diazinon has been used successfully as an emulsion for the control of these pests for years. I believe all of the currently labeled pyrethroids in either wettable powder or microcapsule formulation will be effective if they are applied correctly. It is important to remember that amphipods live under the mulch, so the applicator must apply the material in sufficient volume to penetrate into the moist layers of the mulch if they expect control.

Alternatively, a nonchemical approach would be either to leave them alone and not worry about them, or to perhaps use a rake to pull the mulch away from the foundation and expose the moist areas under the mulch. Allowing these areas to dry out may reduce the amphipod population to a tolerable level without the use of insecticides.

Jeffrey Tucker is president of Entomology Associates, Houston. Questions can be sent to Questions & Answers, c/o Entomology Associates, P.O. Box 70375, Houston TX 77270, or faxed to 713/681-9069.