Cockroaches

Quick facts about cockroaches

  • Cockroaches hide during the day and become active at night.
  • They prefer different habitats depending on the species.
  • Cockroaches are concerning because:
    • they carry human pathogens, and can result in food poisoning or diarrhea.
    • their saliva, feces and cast skins, can irritate allergies and asthma in people, especially children.
  • Cleanliness is very important to reduce cockroach infestations.
  • It is best to hire a pest management service to treat them.

Four kinds of cockroaches can infest homes in Minnesota:

  • German cockroach
  • Brownbanded cockroach
  • American cockroach
  • Oriental cockroach

Submit a sample to an insect specialist or a pest management expert, if you have trouble identifying the type of cockroach.

How to identify cockroaches

Only a small percentage of the actual number of cockroaches in a house, are seen. Correct identification of cockroaches is important as there are many insects that look similar (e.g. long-horned beetles, crickets, leaf-footed bugs and ground beetles).

  • A cockroach has a flattened, oval body and long antennae (about the length of their body).
  • When looking at a cockroach from above, its head is hidden from view.
  • It has six strong legs covered with spines.
  • Many adult cockroaches have fully developed wings, but only few fly.
  • Young, immature cockroaches resemble adults but are smaller and do not have wings.
Egg cases of different species are of different sizes and colors
Cockroach egg cases

Life cycle of cockroaches

  • A cockroach has three stages during its life cycle: egg, nymph and adult.

  • Adults lay eggs contained within dark-colored egg cases (size and shape of a dry kidney bean).

  • Depending on the species, an egg case contains between 16 - 50 eggs.

  • Eggs hatch into young cockroaches called nymphs, that are more numerous than adults.

 

    How to prevent entry of cockroaches

    Cockroaches can be major pests in restaurants, hospitals, warehouses, offices and buildings with food-handling areas. They secrete a substance which can stain surfaces and produce disagreeable odors. They can also destroy fabric and paper products.

    Take precautions while moving

    • When moving, use boxes and packing material from a place free of cockroaches.
    • When packing, watch for cockroaches and their egg capsules.
    • Remove and destroy any that you find.
    • Take all boxes out of the home by night and store in a place without cockroaches.
    • If storing boxes overnight in infested buildings, keep them off the floor and away from walls by placing them on chairs or tables.
    • During winter, you can store boxes in unheated locations such as garages.
    • In your new home, again watch for egg cases and cockroaches that may have survived.

    Remove boxes, newspapers, etc. where cockroaches can breed

    Corrugated cardboard boxes are a good source of cockroach infestations. Examine bags, boxes and luggage brought into your home for the presence of cockroaches or their egg capsules.

    If you think cockroaches may have been brought into your home, you can confirm their presence by:

    • Placing sticky traps so that they are tight against edges, e.g. where walls meet floors.
    • Placing them in areas where cockroaches are likely to occur, e.g. in cupboards and around refrigerators, stoves, and sinks.

    You can reduce the number of cockroaches by eliminating sites for survival and reproduction.

    • Remove corrugated cardboard boxes, newspapers, bags and other unnecessary clutter. When storing items, leave space between the packages.
    • Use caulk to seal spaces and cracks where cockroaches hide. Concentrate on areas where cockroach numbers are the highest.
    • Seal spaces, e.g. with steel wool, in apartments and other multi-unit dwellings where plumbing or electrical wiring goes through walls.
    • Place escutcheon plates at points where plumbing enters the wall, to restrict movement of cockroaches.

    Maintain hygiene and cleanliness 

    If you limit access to food and water, cockroaches cannot survive and reproduce.

    • Keep all food stored in a refrigerator or in insect-proof containers made of plastic, metal, or glass with tight-fitting covers.
    • Do not leave pet food and water out overnight.
    • Wash your dishes, pans, and utensils as soon as you are done using them.
    • Remove all food or spilled drinks from counter tops and clean counters, sinks and tables with soapy water.
    • Vacuum floors, and all cracks and crevices to remove debris and food.
    • Take garbage out daily in closed plastic containers; keep waste containers clean.
    • Repair any leaky water pipes or faucets.
    • Recycle cans and bottles on a regular basis; wash and clean recycling bins.
    • Increase ventilation where condensation is a problem.

    How to protect your home from cockroaches

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    Types of cockroaches

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    Jeffrey Hahn, Extension entomologist and Mark Ascerno, former Extension entomologist

    Reviewed in 2018

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