2. MORPHOLOGY ;
SIZE OF PERIPLANETA AMERICANA IS ABOUT 35MM TO 53MM .
IN MALES THE WINGS EXTENDS BEYOND THE TIP OF ABDOMEN
THE BODY OF COCKROACH IS DIVIDED INTO – 1) HEAD
2) THORAX
3) ABDOMEN
ADULT COCKROACH POSSESES 14 SEMGMENTS IN THE BODY
NO. OF SEGMENTS IN THE HEAD IS ONE , THORAX HAVE THREE , ABDOMEN HAVE TEN
SEGMENTS
HEAD
TRIANGULAR HEAD
A PAIR OF THREAD LIKE ANTENNAE HAVING SENSORY RECEPTORS
A PAIR OF SIMPLE EYE AND A PAIR OF COMPOUND EYE
MOUTHPARTS ARE ; MANDIBLE , MAXILLA , LABIUM( LOWER LIP ) , LABRUM ,(UPPER LIP )
HYPOPHARYNX
BITING AND CHEWING TYPE MOUTH PART FORMED BY ANTERIOR END OF THE HEAD
A FLEXIBLE NECK
3. THORAX HAVE THREE SEGMENTS ; PROTHORAX , MESOTHORAX AND METATHORAX
EACH SEGMENT BEARS A PAIR OF WALKING LEGS
MESOTHORACIC WING IS ALSO KNOWN AD TEGMINA . IT IS OPAQUE AND DARK
METATHORACIC WING IS RESPONSIBLE FOR FLYING . IT IS TRANSPARENT AND MEMBRANOUS
PROTHORAX HAVE SHORT EXTENSION CALLED NECK WHICH CONNECTS THE HEAD TO THORAX .
IN MALES, IN FEMALES ,
THE GENITAL POUCH IS FORMED GENITAL POUCH IS FORMED BY 7TH STERNITE +8TH
BY 9TH AND 10TH TERGITE AND 9TH THE STERNITE AND 9TH STERNITE
GENOPORE
ANUS IS DORSAL SPERMATHECAL BAGS
GENOPORE IS VENTRAL GONAPOPHYSES
GONAPOPHYSES
4. DIGESTIVE SYSTEM OF THE COCKROACHES IS COMPOSED OF ;
1)DIGESTIVE TRACT AND 2) DIGESTIVE GLANDS
MOUTH OPENS TO PHARYNX , PHARYNX OPENS TO OESOPHAGUS ,
OESOPHAGUS TO CROP WHICH OPENS TO GIZZARD.
CROP PERFORMS THE WORK OF SOFTENING AND STORAGE
GIZZARD PERFORMS GRINDING OF FOOD
ALIMENTARY CANAL IS DIVIDED INTO THREE PARTS ; 1) FOREGUT
2) MIDGUT
3) HINDGUT
HEPATIC CECAE IS FOUND AT THE JUNCTION OF FOREGUT AND MIDGUT
IT IS A RING OF 6-15 BLIND TUBULES WHICH PERFORMS THE SECRETION OF
DIGESTIVE JUICES .
COMPLETE FOREGUT IS LINED BY CUTICLE
MIDGUT OR MESENTERON IS LINED BY PERITROPHIC MEMBRANE
MALPHAGIAN TUBULES ARE PRESENT AT THE JUNCTION OF HINDGUT AND
MIDGUT
5. MALPHAGIAN TUBULES ARE YELLOW COLOURED THIN FILAMENTOUS STRUCTURES
WHICH REMOVES THE EXCRETORY WASTES FROM THE HAEMOLYMPH
THEY ARE 100-150 IN NUMBER
HINDGUT IS DIVIDED INTO ILEUM , COLON AND RECTUM
HINDGUT IS THE SITE WHERE MAXIMUM ABSORPTION OF WATER TAKES PLACE
BLOOD VASCULAR SYSTEM OF COCKROACH IS OPEN TYPE
BLOOD OR HAEMOLYMPH IS COMPOSED OF COLOURLESS PLASMA AND
HAEMOCYTES
OPENING OF TRACHEA IS FORMED BY 10 PAIRS OF SPIRACLES PRESENT ON THE
LATERAL SIDE OF THE BODY
TRACHEA OPENS TO TRACHEOLES WHERE THE EXCHANGE OF GASES OCCURS BY THE
MEANS OF DIFFUSION
EXCRETION IS PERFORMED BY MALPHAGIAN TUBULES
MALPHAGIAN TUBES ARE LINED BY GLANDULAR AND CILIATED CELLS
COCKROACHES ARE URICOTELIC ( URIC ACID PRODUCING )
6. NERVOUS SYSTEM OF THE COCKROACH IS SPREADED THROUGHOUT
THE BODY
THREE GANGLIONS ARE LOCATED IN THE THORAX REGION AND SIX
GANGLIONS ARE PRESENT IN THE ABDOMEN
HEAD HOLDS BIT OF NERVOUS SYSTEM
IN HEAD THE BRAIN IS REPRESENTED BY OESOPHAGEAL GANGLION
WHICH SUPPLIES NERVES TO ANTENNAE AND COMPOUND EYE.
COMPUND EYES ARE LOCATED IN THE DORSAL PORTION OF THE HEAD
IN COCKROACHES .