PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
ABDOMEN (contd)
SPIRACLES
Breathing
COMMONLY 8 PAIRS OF SPIRACLES
One pair to each segment.
Used for respiration.
SPIRACLES ARE APERTURES
Spiracles allow oxygen to enter the body and carbon dioxide to pass out.
They can open and close.
The spiracles are the openings which lead into a system of air tubes or
trachea which are spirally strengthened to retain their shape. They branch
and become smaller in diameter until they are called ‘tracheoles’ which end
blindly within cells in all parts of the body. Oxygen and carbon dioxide
diffuse across the thin walls of the tracheoles.
Scarab grub (larva)
Grasshopper (adult)
ANUS
END OF THE ABDOMEN
The anus is usually situated at the end of the abdomen.
MATERIAL EXCRETED
Several different types of materials are excreted through the anus including:
Frass
Honeydew
Spittle
MORE INFORMATION?
Excretions are detailed on the following page.
CORNICLES
CORNICLES ARE TUBE-LIKE STRUCTURES arising from the upper side of
the 5 th and 6 th abdominal segment.
They secrete a defensive fluid.
Cornicles are present on many species of aphids.
Green peach aphid (view from above).
SOUND
MALE CICADAS HAVE A PAIR OF PLATES OR DRUMS on either side of
their abdomen which they vibrate to make their familiar sound. They also have
ears on the abdomen.
Insects and allied pests - Biology 17