Our Wild Neighbors

German Cockroach

Blattella germanica

A cosmopolitan dweller attracted by food and warm and humid environments.

Image of a cockroach, dried and mounted, seen in profile with its head to the left.

Description of the animal

  • Cockroach with a flat, oval body shaped like a shield, which measures between 13 and 16 millimetres long. Its colour varies from bronze to light brown and two dark-hued parallel streaks stretch from its head to the base of its wings.
  • Two pairs of overlapping wings rest flat on its abdomen. The male’s front wings, which are somewhat thicker, cover its posterior wings. The female’s wings are shorter.
  • Two very mobile and flexible antennae, same length as its body.
  • Two large compound eyes.
  • Grinding mouth parts include a pair of strong and very jagged mandibles.
  • Three pairs of similar robust and prickly legs perfectly adapted for rapid movement.
  • Insect with an incomplete metamorphosis. Its young have a similar appearance, but have no wings. The German cockroach goes through six or seven moults before reaching the adult stage.

Habitat and needs

  • Part of a large family containing over 4000 species. The German cockroach is an alien species. It is the most common and urban species. Nine other species live in Canada, but only three are indigenous.
  • Omnivorous and nocturnal, it searches for food in kitchens, bathrooms, basements, and restaurants – all warm and humid environments. It enjoys starch, sweet foods, fat, and meat in particular, but can eat just about anything.
  • Lives in a group. The German cockroach produces an aggregation pheromone, a fragrant substance that attracts others. It is not a social insect, however. Each cockroach lives autonomously and is not dependent on the group.
  • Incapable of sustained flight, in spite of the presence of wings.
  • Runs off at the slightest sign of danger: it is fearful!
  • Can survive without food for nearly 200 days and without water for almost 40 days. Such tenacity!
  • Can become a great-grandparent in less than a year. Since the German cockroach does not abandon her eggs, most of its descendants survive. The female carries her eggs in an envelope called an “ootheca.”

Relationship

  • Sometimes called “coquerelle” in French
  • Once established in a house, the German cockroach can become a genuine scourge. Most of the time, it enters via food packaging.
  • When it is scared, the German cockroach gives off a foul smell.
  • In nature, it plays the role of a decomposer and participates in the recycling process of organic material.
  • It is at the bottom of many animals’ food chain.
  • The German cockroach can transmit infectious diseases and provoke asthma attacks or allergic reactions, but it does not sting or bite.

Living with them

  • To prevent infestation:
  • Avoid bringing objects and foods that could contain cockroaches into your home.
  • Eliminate items that could provide shelter for cockroaches as well as potential food and water sources as much as possible.
  • Keep food in closed airtight containers. Paper bags and cardboard boxes will not prevent cockroaches from reaching food.
  • Rigorously manage waste. Do not leave any food items out. Deposit organic waste in the garbage, in a container with a lid, or in a composter.
  • Keep surfaces clean. Sweep or vacuum regularly. Pull out your stove and refrigerator to wash adjoining walls and floors.
  • Occasionally remove grease from walls, cupboards, and equipment.
  • As much as possible, keep areas that are sources of moisture dry and remove traces of condensation. Repair water leaks and correct excessive humidity.
  • Seal cracks and crevasses.
  • Avoid clutter.
  • When in doubt, set traps. Use traps that contain a sticky material or pheromone traps instead of traps with bait that can attract other types of insects.

Participating cities where this animal has been seen