Ask the Expert: Bed Bugs, Sac Spiders and German Cockroaches

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March 1, 2013

Doug MampeQ: Do bed bugs ever produce solid droppings? All I ever read about are blood stains. K.L., Kan.
A: Like most blood suckers — or any fluid sucker, such as aphids — bed bugs don’t produce solid fecal material. Their system carries the blood (or sap, in aphids) through while removing nutrients. Drywood termites, on the other hand, need to retrieve all water possible from the digestive system, so they produce pellets. Most insects produce solid or semisolid fecal material.

Q: I’ve been called to eliminate a yellow sac spider infestation in a residence. The woman is moving and wants to make sure no spiders move with her. We intend to vacuum all of the hard furniture thoroughly to remove any spiders. I was thinking about using heat to treat clothing and other soft items, as well as electronic equipment, where the spiders might hide. What time and temperature do I need to ensure the kill of spiders and eggs? J.B., Conn.
A: I use a standard rule of thumb for temperature levels and time for heat treatments: 15 and 15. That translates to 115º F and 15 minutes. I haven’t been able to find exact data for sac spiders, but almost everything dies at 115º F within 15 minutes. Remember, it takes time to get clothing and other materials to that critical temperature. If you use thermocouples to measure the temperature, make sure you reach 115º F and hold it for at least 15 minutes. Exceeding that temperature and time will ensure success.

Q: The management company of a high-rise condo client discovered a hoarder living in one of the units. Needless to say, a healthy German cockroach population developed in the unit — and shows up in adjoining units sometimes. They’re moving the hoarder out and asked me to treat the unit. Afterward, a professional cleaning company will remove the trash and clean the unit. I’ve inspected the unit. Books, rags and other items are stacked almost to the ceiling. There are pathways through the mess, so one can get from room to room. There’s no place to spray. I’m thinking about using pelletized baits to knock down the population. Should I also be thinking about heat and other options. A.H., Ill.
A: The use of bait is a good option. Use an insect growth regulator (IGR) to increase bait acceptance. You didn’t mention how much time you have to clean, so baiting alone might be too slow. Treat critical entry points in adjoining units and utility chases with a fast-acting residual before you tackle the problem unit. You might need to drill and treat wall voids of adjoining units. Heating the unit probably isn’t a good option because it will move the roaches into adjoining units. Furthermore, the heat might not penetrate the clutter in the unit sufficiently to provide an effective kill. Another option is the labeled use of dichlorvos (DDVP) strips, which will take several days to produce a lethal concentration but a
high level of control.

Contact Dr. Mampe, an industry consultant, at dentomol@aol.com.

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