- German cockroach
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German cockroach/ Hood 
Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Blattodea Family: Blattellidae Genus: Blattella Species: B. germanica Binomial name Blattella germanica
Linnaeus, 1767
Female German Cockroach with ootheca.
The German cockroach (Blattella germanica) is a small species of cockroach, measuring about 1.3 cm (0.51 in) to 1.6 cm (0.63 in) long; however, they are known to get bigger. It can be tan through brown to almost black, and has two dark parallel streaks running from the head to the base of the wings. Although it has wings, it is unable to sustain flight. The German cockroach is the number 1 roach in the World[1], and can be found throughout many human settlements. These insects are particularly associated with restaurants, food processing facilities, hotels, and nursing homes. In colder climates, they are found only near human habitats, since they are not very tolerant to cold. However German cockroaches have been found as far north as Alert, Nunavut.[2] The German cockroach is originally from Africa, it is very closely related to the Asian cockroach, and to the casual observer they appear nearly identical and may be mistaken for the other. This cockroach can be seen in the day occasionally, especially if there is a large population or if they have been disturbed. However, sightings are most commonly reported in the evening hours as they are most active at night. This type of cockroach can emit an unpleasant odor when excited or frightened.
Contents
Pest control
The German cockroach (also known as a "hood" in the U.S.) is very successful at establishing an ecological niche in buildings, and is very hardy and resilient against attempts at pest control. This is because of the large number of nymphs produced from each egg case, the short period between birth and sexual maturity, and their ability to easily hide due to their small size. The mother also carries the egg case (called an ootheca) with her during the germination period, rather than depositing it like other species, a practice which would leave them vulnerable in a human habitat to zealous attempts to wipe them out. This cockroach is also smaller than many other species so it can more easily hide and fit into very small cracks and crevices to evade humans. That is also the main reason they can most effectively be controlled with bait in cracks and crevices near harborages.[3] These type of pest control methods should kill 95% of the overall population in a property due to their fast reproductive cycles.[4] The German cockroach, discounting the presence of pets, has few natural predators inside a human habitat. The German cockroach's thigmotactic nature compounds the difficulty of pest control treatment. The immature cockroaches will live off excretions and moults from the adult cockroaches and thus can remain hidden away from most surface treatments.[5]
Diet
The German cockroach is omnivorous and a scavenger. They particularly like starch, sugary foods, grease and meats. In certain situations where there is a shortage of foodstuffs, they may eat household items such as soap, glue and toothpaste or they may even turn cannibalistic, often chewing on the wings and legs of each other.
Comparison of three common cockroaches
Cockroach German cockroach Oriental cockroach American cockroach Size 12 mm (1.2 cm) to 15 mm (1.5 cm) 25 mm (2.5 cm) to 30 mm (3.0 cm) 28 mm (2.8 cm) to 43 mm (4.3 cm) Habitat Heated buildings, optimum 32 °C (90 °F) 20 °C (68 °F) to 29 °C (84 °F) Same as German Nymphal development time 6 to 12 weeks 6 to 12 months 4 to 15 months Life Span 6 to 9 months 1 to 1.5 years 1 to 1.5 years Able to fly? No No Yes See also
- Blattellaquinone, a sex pheromone of the German cockroach
References
External links
- German cockroach on the UF / IFAS Featured Creatures Web site
- German cockroach fact sheet from the Penn State Extension
- German cockroach information page from the EX-PEST website
Categories:- Cockroaches
- Household pest insects
- Animals described in 1767
- Urban animals
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