WING VENATION IN INSECTS

 wing is one of the most characterstic feature of insects.
 In majority of insects mesothorax and meta thorax carries a pair of wings.
 On the basis of presence of wings class insecta is devided into 2 sub classes :
1. APTERIGOTA
2. PTERIGOTA

1. WING VENATION IN INSECTS

2. WING wing is one of the most characterstic feature of insects . In majority of insects mesothorax and meta thorax carries a pair of wings. On the basis of presence of wings class insecta is devided into 2 sub classes : APTERIGOTA PTERIGOTA

3. AREAS OF WINGS The wing is triangular in shape having 3 margins- ANTERIOR MARGININ OR COSTA OUTER OR APICAL MARGIN INNER OR ANAL MARGIN

4. WING VENATION Each of the wings consists of a thin membrane supported by a system of veins i.e called venation.

5. The membrane is formed by two layers of integument closely apposed, while the veins are formed where the two layers remain separate. sometimes the lower cuticle is thicker and more heavily  sclerotized  under a vein. Within each of the major veins there is a nerve and a trachea. since the cavities of the veins are connected with the  hemocoel , hemolymph can flow into the wi ngs.

6. The lines of venation have been “mapped” with a common terminology called Comstock – Needham system. It was devised by John  Comstock  and George  Needham  in 1898. It was an important step in showing the homology of all insect  wings . This  system was based on  Needham's  pre- tracheation theory that was later discredited by Frederic Charles Fraser in 1938. HISTORY

7. VEINS The principal veins run more-or-less lengthwise on the wing--thus called  longitudinal veins . Connecting them are a lesser number of  cross-veins . A closed area bounded by veins is called a  cell .

8. TYPES OF VEINS According to current dogma, the archedictyon contained 6–8 longitudinal veins. These veins (and their branches) are named according to a system devised by John Comstock and George Needham.

9. Costa (C)  – the leading edge of the wing Subcosta ( Sc )  – second longitudinal vein (behind the costa), typically unbranched . Radius (R)  – third longitudinal vein, one to five branches reach the wing margin Media (M)  – fourth longitudinal vein, one to four branches reach the wing margin Cubitus (Cu)  – fifth longitudinal vein, one to three branches reach the wing margin Anal veins (A1, A2, A3)  – unbranched veins behind the cubitus

10. CROSS-VEINS C-Sc cross-veins  – run between the costa and subcosta R cross-veins  – run between adjacent branches of the radius R-M cross-veins  – run between the radius and media M-Cu cross-veins   – run between the media and cubitus

11. EXAMPLES OF MODIFICATION OF WINGS IN DIFFERENT ORDERS

12. ORDER:BLATTODEA (cockroach)

13. ORDER:COLEOPTERA (beetles)

14. ORDER:DERMAPTERA (earwigs)

15. ORDER:DIPTERA (flies and mosquitos ) Single vein R2+3 inspite of separate R1 and R3. R4 and R5 are also modified as single vein

16. ORDER:EPHEMEROPTERA ( mayflies)

17. ORDER:HEMIPTERA (diving beetles,cicadas )

18. ORDER:HYMENOPTERA ( Bees,bumblebees,wasp,ants )

19. ORDER:ISOPTERA (TERMITES)

20. ORDER:LEPIDOPTERA (BUTTERFLIES,MOTHS)

21. ORDER:MANTODEA (PRAYING MANTIS)

22. ORDER:MECOPTERA (SCORPION FLIES)

23. ORDER:NEUROPTERA (LACEWIGS)

24. ORDER:ODONATA (DRAGONFLIES)

25. ORDER:ORTHOPTERA (GRASSHOPPER,LOCUST)

26. Thank you