Creative Cockroach Control

German Cockroach

OK I'm thoroughly sick of cockroaches. Even though I've been pretty good lately about not leaving any food lying around, there seems to be no letup in the number of these little nasties running around. Worse is that they're coming into my study a lot more, perhaps because I have baits in the kitchen. The aquarium provides them with a source of water, so they've taken up residence in here >:(

So I'm now on a quest to find fish-friendly, chemical free methods of cockroach extermination. I've yet to try any of the following methods, so any comments on their successfulness would be appreciated!

Some methods I've found on the web include:


  • A bowl of cheap wine placed under the sink will kill roaches; they drink, fall in and die
  • Set out water and dry cement where roaches visit; they will ingest both and die
  • Cedar, Japanese mint, scotch spearmint, and bay leaves are good natural repellents and make good barrier treatments
  • Woodstream Corporation’s Victor Poison-Free Ant & Roach Killer� uses a 4% Japanese mint essential oil blend as an effective knockdown treatment for American and German roaches
  • Ordinary soap sprays or solutions that use common dishwashing liquids can also be used against roaches for similar knockdown effects
  • Dorsey Inc. (Shellshock�) is a desiccant made up of 85% diatomaceous earth and comes in a squeeze dust applicator. It is slower acting (six weeks or more), but roaches will stay away longer
  • Desiccants such as silica gels and diatomaceous earth products stimulate roaches and other insects that come into contact with them to immediately seek out a moisture source. Without a water source, they will quickly dehydrate and die
  • Dorsey Inc. (Repeel�) is a desiccant made up of diatomaceous earth and citrus oil from orange peel and is useful as a barrier treatment
  • Silica gel and diatomaceous earth can both be used inside houses to treat cracks, wall crevices and voids, and attics to repel roaches and deny harborage in these areas
  • Organic Plus Inc. (Organic Plus�) is a desiccant registered for home and garden use for roach control
  • BioLogic produces a gel formulation (BioRoach™ and Roach Stopper™) which contains live nematodes in bait stations which can be used in areas where roaches frequent. Roaches are attracted to the water in these baits, and are then infected and killed by the nematodes. Nematodes are microscopic parasitic worms that are harmless to humans and animals, but are able to infect and kill insects
  • Garlic oil is highly repellent to German roaches
  • The use of talc with citrus oil soap sprays will facilitate cuticular penetration and control roaches more effectively
  • Insects can be trapped and killed without resorting to dangerous chemicals: generally a poison nontoxic to humans is mixed with a food that insects find attractive, and spread in the infested area. Examples are oatmeal (attractive) and plaster-of-Paris (poisonous), and cocoa powder and flour (attractive) and borax (poisonous)
  • Apparently if you mix a dish of plaster of paris with sugar the cockroaches head for it like bees to honey. You place next to it a small amount of water which the cockroaches drink (I didn't know that cockroaches drank personally), and then the water hardens the plaster of paris and they simply harden from the inside out
  • Sanitation is the key to keeping cockroaches from taking over. Don't leave food uncovered. This includes pet dog food. Pour a little bleach down drains. Cockroaches keep away from the smell of chlorine. Keep drains covered--roaches love to use drains as watering holes.
  • Diatomaceous earth is mined from the fossilized silica shell remains of diatoms, microscopic sea animals. The advantage to this substance is that it is virtually non-toxic to humans. Because it has an abrasive quality, diatomaceous earth degrades the waxy layer causing the insect to dry out and die. It is important that only natural diatomaceous earth be used for insect control not DE treated for swimming pool filter use, as this contains crystalline silica, a dangerous respiratory hazard. One source of DE may be found at feed stores for horses and cattle. A member of the staff here at EAD uses this and says that it is easy to use with good results.
  • Silica aerogel is a non-abrasive, chemically inert substance that is used as a dehydrating agent because the small particles absorb moisture and oils. Sometimes small bags of silica aerogel are inserted in electrical equipment packages to prevent the accumulation of moisture during shipping or storage. Silica aerogel is also used in the florist trade and often can be purchased from a florist. The silica aerogel particle has a static charge that enables it to stick tightly to the cockroach body. Once on the body, the aerogel absorbs the waxy protective coating which desiccates and kills the cockroach.
  • Prevention is the best protection - see the section on Prevention. Additionally, you can try mixing 1 part borax, 2 parts flour and 1 part icing sugar, add enough water to mix to a thick dough and then knead well. This can be used on cracks behind skirting boards and cupboards, but remember borax is poisonous. Clean thoroughly behind cupboards and stoves - cockroaches also love electrical equipment.
  • An open bottle of eucalyptus oil or tea-tree oil can be very effective in cupboards or near susceptible areas. Non-Chemical Sticky traps are available commercially (try a health food shop first). A heat gun which emits very hot air can be used to flush out and kill cockroaches or alternatively close windows and doors, turn on lots of heaters to get the temperature of the house to 50�C for three hours - obviously the middle of summer is an ideal time to try this. Try a bait of icing sugar and borax in a jar placed near cockroach run. Fill a margarine container three quarters full of water: add a dessertspoon of cooking oil which will float on top of the water: the cockroach climbs into the container, but the floating oil makes it very difficult for it to escape. Place near cockroach sites.
  • Make a non-toxic roach bait and set it out in roach infested areas:

    1/2 cup sugar
    1/4 cup shortening or bacon drippings
    1/2 cup chopped onion
    1/2 cup flour
    8 ounces baking soda

    Combine sugar and shortening. Add onion, flour, and baking soda. Mix in just enough water to make a dough-like consistency. Put small balls in plastic sandwich bags (other alternatives: spread some on margarine tub lids, or put in a lidded plastic container with small roach-sized holes cut in the bottom of the sides for the roaches to use to get in and out but that will keep pets out) and place in roach-infested areas. The bait creates gas in the roach when eaten. Because roaches can't belch, their digestive tracts explode.


Sites referenced:
http://www.symbios-witticism-page.com/bug.htm#6
http://www.darlingsindiapers.com/Mothers2Mothers/dangeroushomes02_iaw.htm
http://www.web-therapy.com/cockroach.htm
http://www.co.forsyth.nc.us/EnvAffairs/wqts/pest.htm#COCKROACHES
http://www.ecwa.asn.au/info/altpest.html#cockroaches
http://www.anapsid.org/pestcontrol.html#roaches

If anyone has any more creative solutions for killing cockroaches, and that's safe to use around tropical fish, post a comment! :)