Example of Cockroach Reproduction

An Example of German Cockroach Reproductive Capability

• German cockroaches are among the most difficult pests to get rid of. The reason is simply because they reproduce exponentially. We will present an example of how a single breeding pair of German cockroaches can overwhelm a typical residence. Note that cockroach infestations can peak when the population peaks at between 500-600 roaches per square foot!
• A single female German cockroach can reproduce every twenty days, producing at least 30 new roaches. We will assume that our roach population is 50% female, and to reflect that we will assume that every roach will produce 15 new roaches every 20 days.
• We will also assume that the infested residence is a 2,000 square foot property.
• Day 1: two roaches, male and female, take up residence in our property.
• Day 20: Our two roaches reproduce and create 30 new roaches. New roach population: 32 roaches.
• Day 40: Our 32 roaches reproduce again, creating 32*15 or 480 roaches. New roach population: 512 roaches.
• Day 60: Our 512 roaches reproduce again, creating 7,680 new roaches. New roach population: 8,192 roaches.
• Day 80: Our 8,192 roaches reproduce again, creating 122,880 new roaches. New roach population: 131,072 roaches.
• Day 100: Our 131,072 roaches reproduce again, creating 1,966,080 new roaches. New roach population: 2,097,152 roaches.
• 2,097,152 roaches divided by 2,000 square feet = 1,049 roaches per square feet.
• We know that roach populations typically peak around 500-600 individuals per square foot.
• Conclusion: Left unchecked, a German cockroach infestation will reach peak population of 500-600 individuals per square foot within approximately 90 days of the initial infestation.