Information on cockroach
CLASSIFICATION
Domain : - Eukaryote
Kingdom : - Animalia
Phylum : - Arthropoda
Class : - Insecta
Order : - Dictyoptera
Genus : - Periplaneta
Species :- Americana
Habitat
Cockroaches are found at places where there is warmth and food remains i.e. warm, dark and damp places. They commonly inhabit kitchens, restaurants, bakeries, grocer's shops, fruit stalls, store houses, godowns, railway wagons, ships, etc. They are numerous in underground drains and sewage systems.
General Characteristics
The cockroach has an elongated, ovoid, dorso-ventrally flattened, bilaterally symmetrical body. It is shining dark brown in colour. It is 2-4 cm long and 1 cm wide. The body of cockroach is externally covered by hard brown chitinous plates called sclerites. The sclerites are joined with one another by thin, flexible, soft articular or arthrodial membranes. The various sclerites collectively constitute the exoskeleton.
Cockroaches are found at places where there is warmth and food remains i.e. warm, dark and damp places. They commonly inhabit kitchens, restaurants, bakeries, grocer's shops, fruit stalls, store houses, godowns, railway wagons, ships, etc. They are numerous in underground drains and sewage systems.
General Characteristics
The cockroach has an elongated, ovoid, dorso-ventrally flattened, bilaterally symmetrical body. It is shining dark brown in colour. It is 2-4 cm long and 1 cm wide. The body of cockroach is externally covered by hard brown chitinous plates called sclerites. The sclerites are joined with one another by thin, flexible, soft articular or arthrodial membranes. The various sclerites collectively constitute the exoskeleton.
Exoskeleton protects the body and provides space for the attachment of muscles. The body is distinctly divided into 3 regions: - Head, thorax and abdomen.
Head lies at right angle to the long axis of body and is called hypognathous. Neck is short, soft and thin region which connects the head with thorax and allows the movement of head in all directions. Top of head capsule, vertex, is divided into two epicranial plates by an epicranial suture. Cockroaches have kidney shaped, dorsolaterally placed compound eyes which allow them to see simultaneously in almost all directions around its body. Each eye is made up of 2,000 individual hexagonal lenses called omatidia. Near the eye there is a pair of long, slender, tapering filaments called antennae which arises from antennal socket and can be moved in all the directions. Antenna has tactile sensory bristles which help in detecting the presence of food and the object in front.
Head lies at right angle to the long axis of body and is called hypognathous. Neck is short, soft and thin region which connects the head with thorax and allows the movement of head in all directions. Top of head capsule, vertex, is divided into two epicranial plates by an epicranial suture. Cockroaches have kidney shaped, dorsolaterally placed compound eyes which allow them to see simultaneously in almost all directions around its body. Each eye is made up of 2,000 individual hexagonal lenses called omatidia. Near the eye there is a pair of long, slender, tapering filaments called antennae which arises from antennal socket and can be moved in all the directions. Antenna has tactile sensory bristles which help in detecting the presence of food and the object in front.
Cockroach has very long legs. Each leg is composed of five parts or podomeres namely coxa, trochanter, femur, tibia and tarsus. Terminal part has claws and pads that help cockroach in holding the substratum firmly. Hairs on the legs of a cockroach provide an extra sense of touch. There are present two pairs of wings on cockroach. Wings are membranous outgrowths of body wall supported by network of nervures. The first pair is called mesothoracic wings and are not used in flight. They are protective in function. The second pair known as metathoracic wings is the real organ of flight.
Abdomen is the posterior and largest part of the body having ten segments. Certain segments have spiracles and stink glands. There are eight pairs of spiracles which lead into tracheae and help in respiratory exchange of gases. The stink gland's secretion gives a characteristic foul smell to cockroach. Cerci are the two little hairs on the rear end of a cockroach. They act like a motion detector.
Reproduction
Cockroaches are unisexual and oviparous. Male genital aperture is situated on 10th abdominal segment and genital aperture of female lies on 8th segment. There are small chitinous processes around genital apertures of both male and female called gonapophyses.
To attract mates, the female cockroach produces an odour (a pheromone) that excites male cockroaches. Male and female cockroaches come together by their posterior ends. Males produce a package of sperm called spermatophore which is covered by three layers.
Abdomen is the posterior and largest part of the body having ten segments. Certain segments have spiracles and stink glands. There are eight pairs of spiracles which lead into tracheae and help in respiratory exchange of gases. The stink gland's secretion gives a characteristic foul smell to cockroach. Cerci are the two little hairs on the rear end of a cockroach. They act like a motion detector.
Reproduction
Cockroaches are unisexual and oviparous. Male genital aperture is situated on 10th abdominal segment and genital aperture of female lies on 8th segment. There are small chitinous processes around genital apertures of both male and female called gonapophyses.
To attract mates, the female cockroach produces an odour (a pheromone) that excites male cockroaches. Male and female cockroaches come together by their posterior ends. Males produce a package of sperm called spermatophore which is covered by three layers.
Gonapophyses of male open the brood pouch or genital chamber of female and spermatophore is transferred into it by help of three chitinous structures called phallomeres. Sperms are liberated from the spermatophore and they reach spermatheca. Eggs come from both ovaries and pass into genital chamber where they are fertilized by sperms from ootheca. Certain secretion form egg case or ootheca in which eggs are kept. Young ones that hatch from eggs resemble the adult and are called nymphs. Nymphs undergo moulting or ecdysis 6-7 times and grows to become adult in one year.
Nutrition
The biting and chewing mouth parts of cockroach consist of a labrum, two mandibles, two maxillae, a labium and a hypo pharynx. Labrum and maxillae hold the food, mandibles cut and masticate the food, and labium checks the loss of food particles from mandibles as they are being chewed up. Hypo pharynx receives saliva from salivary duct and directs it on to the food. Cockroaches are omnivorous. They feed on almost all kinds of food matter including human food, paper, leather, cloth and dead bodies of animals, even dead bodies of their own fellows (cannibalism). They prefer starch containing food.
Economic Importance
Cockroaches cause damage to house hold materials such as clothes, shoes, purses and paper. They pollute and consume our food - fruits, bread, cheese, etc. They also spread foul smell in kitchens. The cockroaches are eaten in certain parts of the world such as Myanmar and South America. Many animals such as amphibians (e.g., frogs, toads), lizards, birds and rodents eat cockroaches. They are part of food chain. They are also used as laboratory animals.
Nutrition
The biting and chewing mouth parts of cockroach consist of a labrum, two mandibles, two maxillae, a labium and a hypo pharynx. Labrum and maxillae hold the food, mandibles cut and masticate the food, and labium checks the loss of food particles from mandibles as they are being chewed up. Hypo pharynx receives saliva from salivary duct and directs it on to the food. Cockroaches are omnivorous. They feed on almost all kinds of food matter including human food, paper, leather, cloth and dead bodies of animals, even dead bodies of their own fellows (cannibalism). They prefer starch containing food.
Economic Importance
Cockroaches cause damage to house hold materials such as clothes, shoes, purses and paper. They pollute and consume our food - fruits, bread, cheese, etc. They also spread foul smell in kitchens. The cockroaches are eaten in certain parts of the world such as Myanmar and South America. Many animals such as amphibians (e.g., frogs, toads), lizards, birds and rodents eat cockroaches. They are part of food chain. They are also used as laboratory animals.
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