Oriental cockroach

Oriental cockroach
A: Female B: Male C: Side view of female D: Young male
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Blattodea
Family:	Blattidae
Genus:	Blatta
Species:	B. orientalis
Binomial name
Blatta orientalis Linnaeus, 1758

The oriental cockroach (Blatta orientalis), also known as the waterbug, is a large species of cockroach, adult males being 18–29 mm (0.71–1.14 in) and adult females being 20–27 mm (0.79–1.06 in). It is dark brown to black in color and has a glossy body. The female Oriental cockroach has a somewhat different appearance from the male, appearing to be wingless at casual glance but has two very short and useless wings just below her head. She has a wider body than the male. The male has long wings, which cover two thirds of the abdomen and are brown in color, and has a narrower body. The odd male is capable of very short flights, ranging about 2 to 3 meters. The female oriental cockroach looks somewhat similar to the Florida woods cockroach, and may be mistaken for it. Originally endemic to the Crimean Peninsula and the region around the Black Sea and Caspian Sea, its distribution is now cosmopolitan.

Habitat

The oriental cockroach tends to travel somewhat more slowly than other species. They are often called "waterbugs" since they prefer dark, moist places. They can often be found around decaying organic matter, and in sewers, drains, damp basements, porches, and other damp locations. They can be found outside in bushes, under leaf groundcover, under mulch, and around other damp places outdoors. They are major household pests in parts of the northwest, mid-west, and southern United States.

Adaptation

In order to thrive, cockroaches need a place to hide. They prefer warm places and a relatively high humidity if possible; they also need a source of food/liquid. The optimum temperature for oriental cockroaches is between 20 °C (68 °F) to 29 °C (84 °F). Female oriental cockroaches have vestigial tegmina (reduced forewings) and males have longer tegmina. Cockroaches are mainly nocturnal. Oriental cockroaches can be elusive in that a casual inspection of an infested dwelling during the day may show no signs of roach activity. Oriental cockroaches can be found in usually damp places such as sewer pipes, sink drains, and any other form of damp areas in households.

Oothecae

Signs of cockroaches are their oothecae, which are “egg cases”. The blackish brown oothecae of the oriental cockroach are 10–12 mm (0.39–0.47 in) long, with indistinct egg compartments housing 16–18 eggs. These oothecae are formed a day after mating, and typically deposited a day or two after formation, though it can be deposited up to 7 days later. It is typically deposited in a sheltered area or attached to a substrate by oral secretion. They are initially a yellow white, turning reddish brown then blackish brown. They lose viability at temperatures below 0 °C (32 °F). They hatch on their own in about 42 days at 29.5 °C (85.1 °F) and 81 days at 21 °C (70 °F).

Pest Control

Oriental cockroaches can be harder to get rid of than other roaches. Although adults can be fairly easily killed by the application of residual insecticide, the insecticides can get washed away, and two months later females can hatch new nymphs.

Comparison of three common cockroaches

Roach	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?	Barely	No	Yes

External links

• Oriental cockroach on the UF / IFAS Featured Creatures Web site
• Oriental cockroach egg parasitoid on the UF / IFAS Featured Creatures Web site.
• Oriental Cockroach Fact Sheet from the National Pest Management Association with information on habits, habitat and health threats
• Black and white photographs of top view of B. orientalis male and female specimens, from Smithsonian Miscellaneous Collections.