American cockroach (Periplaneta americana)

(Photo credit to Gary Alpert, Harvard University, Bugwood.org)

Periplaneta americana is the largest species among the common cockroaches. Adult female are 29 to 36 mm long and adult male are slightly longer than female with 34 to 53 mm in length. The wings in male are extended beyond the abdomen and the wings are as long as abdomen in female. The newly emerged nymphs are white and slowly become darker in color.  The adult is reddish brown with a pale brown band around the edge of the pronotum. This species is originated from Africa and has been spread to other part of the world. It is mainly found in sewers and drainage systems. During the day time, they normally hide in the dark, sheltered, and narrow places.

German cockroach (Blattella germanica)

(Photo credit to Gary Alpert, Harvard University, Bugwood.org)

Blattella germanica is the small species of cockroach. The adults are 12 -16 mm long. The body is light brown or yellowish-brown and females are slightly darker than males. One identification clue for this species is there are two brown or black longitudinal stripes on the pronotum. This species is cosmopolitan in distribution and could be found throughout the world. In urban environments, this species lives only indoors with high humidity, and the presence of food and harborage. It is common to see this species in kitchen area or restaurants.

Pacific beetle cockroach (Diploptera punctata)

(Photo credit to Len Worthington)

Diploptera punctata, as their common name, Pacific beetle cockroach, is a type of beetle-mimic cockroach. It looks alike to a beetle and generally found outdoors beneath leaf litter and around the base of plants. One interesting feature of this species is that they give birth to live young instead of laying eggs.

Harlequin cockroach (Neostylopyga rhombifolia)

(Photo credit to Len Worthington)

Neostylopyga rhombifolia could be easily identified with the black with yellow pattern on the adult body. The front wings are short and the hind wings are absent in adult. It is about 25 to 30 mm long and primarily found outdoors around buildings. It is native to southern Asia but is distributed in tropical regions around the world.

Brown-banded cockroach (Supella longipalpa)

(Photo credit to Gary Alpert, Harvard University, Bugwood.org)

Supella longipalpa is a small species of cockroach with body length of 10 to 14 mm. The body is yellowish-brown with distinct pale brown banding. Adult males are longer than adult females. The abdomen of adult males are fully covered by the wings, while the wings is shorter than abdomen in adult female. Besides, the adult female has a wider and larger abdomen compared to adult male. This species normally widely distributed indoors such as in living room and bedroom. They are less commonly found in restaurants.

Surinam cockroach (Pycnoscelus surinamensis)

(Photo credit to Gernot Kunz)

Pycnoscelus surinamensis is a species of burrowing cockroach. Adults are 18 to 25 mm in length. They have a dark brown or brown body with shiny wings and pronotum. The pronotum are usually dark brown or black with yellow front and side margin. This species is normally found in the soil or beneath plants and rocks. They prefer to burrow in loose litter. However, they may sometimes crawl into homes. They feed on plants and may cause significant damages to plants.

Prevention of Cockroaches

Effective control of cockroaches at home highly relies on sanitation and hygiene that reduce the food and shelter for the cockroaches. Some of the non-chemical practices are listed below:

• Clean up the food-handling area immediately and regularly. Dishes and utensils in the sink area should not be left unwashed overnight.
• Water availability should be reduced. Water dipping or leaking should be checked regularly.
• Remove trash from your home daily or stored in tightly closed containers.
• Routinely sweep and mop the kitchen and pantry area.
• Store food and drinks in sealed containers.
• Cracks and crevices should be sealed to avoid harborage of cockroaches.

Control of Cockroaches

There are several chemical controls used in controlling cockroaches such as surface sprays, space sprays, dusts, baits, and traps. Read carefully and follow the instructions on the label before applying any chemical treatment. It is advisable to consult pest control professionals if you found cockroaches in your home. A proper species identification and an inspection on the level of infestation followed by the appropriate treatment is important in cockroach management.

References

• Urban Insects and Arachnids: A Handbook of Urban Entomology (2005). William H Robinson. Cambridge University Press.
• Urban Pest Control in Australia (1985). P Hadlington and J Gerozisis. New South Wales University Press.
• NPMA Field Guide to Structural Pests, Second Edition (2007). Eric H. Smith and Richard C. Whitman.