Except for dimension, all cockroach species have the same shape and characteristics. They forage for food at night and live in dark places. When they appear in light places, this means that there are big quantities of cockroaches there. Cockroaches like residing in narrow places so that their body can access to both upper and lower surface. When grown-up, they will find another residence. Their shape will change in different environment conditions.
There are 4 most popular species of cockroaches in our country as follows:
+ American cockroach
+ German cockroach
+ Brown-banded cockroach
+ Oriental cockroach
Life cycle
Cockroaches are rather primitive insects without complete metamorphosis. Their life cycle spends 3 stages: eggs, larvae and adults. Female cockroaches lay eggs combined in capsule. Some species like German cockroach carry egg cases on the end of their abdomens. Most of other species lay eggs after 1 or 2 days. Depending on species and temperature, humidity of the environment, cockroach eggs may be hatched after 1 to 3 months.
Female cockroaches usually hide in safe places to protect egg cases. In emergency cases, they may leave such cases and run away. Cover of egg cases is very hard to protect eggs. Where there are many cockroaches, egg cases will be present. Even when the whole group of cockroaches is exterminated, lots of eggs in cases still continue to hatch.
Habit and shelter
Cockroaches are mainly noctumal. In the daytime, they reside in hollows, wall crevices, chinks of doors and cabinets and secret places in bathrooms, dressers, water-pipes, cowsheds, TV and radio shelves and other electronic appliances, sewerage system etc. At night, if we turn on the light in the kitchen, cockroach may fly in disorder over bowls and dishes, cooking utensils and floor to look for shelters.
House cockroaches are omnivorous insects. They eat all kinds of human food but prefer starch and sugar. They gnaw milk, butter, sweet cake etc. Cockroaches also gnaw book covers and backs, shoes soles and even their own ootheca, head cockroaches, dry and fresh blood, feces, toenails and fingernails of children, sleeping or sick people. Most of cockroaches live in highly-humid places and near food sources. They will find another shelter which fits their body. When there are too many cockroaches to live together in one shelter, they resort to leaving there to look for a new place on the way to forage for food before daytime and after nightfall.
American Cockroach
Characteristic: brown and slightly red. There is light stripe after head. Long tail
Length: 25 - 40 mm
Residence: in humid regions, steam holes, sewerage, trees.
Food: organic substances (decayed leaves), sweet substances and starch.
Stage of life cycle: Capsule dropped near food sources, 60 days of hatching, taking around 1 year for eggs to become adult cockroaches.
Remark: found all over the world
Brown-banded Cockroach
Characteristic: light brown at two crossed bands through wings
Length: 12 mm
Residence: favorite places in around 800F or higher, found at attics, furniture, high places in room, not found in wet places
Food: substances rich in starch
Stage of life cycle: not carrying eggs for long time; egg cases touching the surface, every case containing 10-18 eggs, taking 70 days for eggs to hatch
Remark: mainly in restaurants, hotels, wagon …
German Cockroach
Characteristic: brown-2 black spots after head
Length: 12-15mm
Residence: living near human food and water sources, hiding in slots, foraging for food at night mainly in kitchen
Food: any fermented food of human
Stage of life cycle: Laying one egg case in 1-2 months, every case contains from 24-48 eggs which will hatch after 28 days. Cockroaches carry eggs around 24 hours before eggs hatch. Adult cockroaches live up to 180 days.
Remark: mainly in restaurants, hotels, wagons…
Oriental Cockroach
Characteristic: dark brown and black. Females has got a small part of meat under wings, males have wings covering ¾ abdomen
Length: 1-1/4’’ (25-30 mm)
Residence: humid regions, basement, floors, chinks. They may creep into sewerage
Food: garbage or decayed organic substance
Stage of life cycle: Dropping eggs in humid places, every capsule containing 12 - 16 eggs. Eggs will hatch after 60 days