Important Points to Remember of Chelicerae

Chelicerae : First pair of chelate or sub-chelate, prehensile, pre-oral appendages in arachnids.

Sclerites : Skeletal plates of insects-dorsal terga (singular-tergum), ventral sterna (singular-sternum), lateral pleura (singular-pleuron) joined by arthrodial membranes.

Pedipalpi : A pair of second cephalothoracic appendages in arachnids with or without a pincer-like claw.

Pollen Basket : Depression on the outer surface of tibia of each metathoracic leg in honeybee.

Arthropod Respiration : It is of two main types, direct and indirect. In direct respiration, gaseous exchange occurs between air and cells through tissue fluid. No respiratory pigment is involved. Air is taken to the tissues by a system of branching tubes or tracheae. In indirect method gaseous exchange occurs between air/water and blood which contains a respiratory pigment called haemocyanin (dissolved in plasma). Haemocyanin is bright blue in the oxygenated state and colourless in the deoxygenated state.

Loudest Insect : Cicada, sound audible at 4.0 km distance.

India produces 10% of world’s total silk production.

Best silk is obtained from silk moth raised on mulberry trees.

Chelipedes : Claw bearing appendages.

In a colony of honeybees a queen (fertile female), 1 to few 100 drones (fertile males) and up to 60,000 workers (sterile females) are found.

The venom of honeybees is used in treatment of arthritis and snake bite.

One pound of silk is obtained from about 25,000 cocoons.