Understanding Insect Taxonomy: Pterygota Orders in Hexapoda Class

2. Asma Noor ul Ain

3. Presentation of systematics Topic: Subclss pterygota Order orthoptera Order odonata Order phasmida

4. contents • Class hexapoda • Subclass pterygota • Endopterygota • Exopterygota • Exopterygota orders • Order Orthoptera • Characters • Examples • Order odonata • Charaters • Examples • Order phasmida • Characters • Examples • References

5. Class hexapoda: • Hexa = six and poda = legs • So it include insects having 3 pair of legs • Two subclasses: • Apterygota (primitive wingless insects) • Pterygota (winged and secondarily wingless insects)

6. Subclass Pterygota: • Pterygota means “wings,” • Describes insects having wings, or once had wings in their evolutionary history • Includes most of the world’s insect species • The winged insects (Pterygota) distinct stages of development before they become adult. • Incomplete metamorphosis (Egg > nymph > adult) • Complete metamorphosis (Egg > Larva (more precisely: larval instars) > pupa > adult)

7. s Complete metamorphosis Incomplete metamorphosiss

8. Classification of pterygota • The details of the process of metamorphosis allows the winged insects to be classified into two main groups: • Exopterygota (insects with incomplete metamorphosis, without pupal stage) • Endopterygota (insects with complete metamorphosis, including a pupal stage)[2]

9. Endopterygota: • Refers to the development of the wings inside the body. • Complete metamorphosis. • External changes are greatest. • The eggs hatch into larvae . • Larvae may or my not have legs. • Development of wing s is not visible in larvae.

10. After several molts pupa is formed. • Pupa is inactive stage. • Sometime pupa is protected by cocoon silk or found in earthen cell in soil. • Big changes internally take place during pupal stage. • After pupal stage highly active winged adult appears.

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12. Exopterygota: • Exopterygota ("external winged forms") develop wings on the outside of their bodies without going through a true pupal stage, though a few have something resembling a pupa. • The young resemble adults but have externally-developing wings. • They undergo a modest change between immature and adult • nymphs develop gradually into adults through a process of moulting.

14. Highly diverse insect super order, with at least 130,000 living species divided between 15 orders. • include termites, locusts, thrips, lice and stick insects, among many other types of insects. • Encompassing plant feeders, predators, and animal parasites, and living in nearly all habitats and areas where insects are found.[3]

15. Characteristics of Exopterygota: • Simple or incomplete metamorphosis. • The life cycle includes just three stages – egg, nymph, and adult • There is gradual exchange in external appearance. • Late nymph shows the development of the wing pads. • But only in last molt functional wings are developed. • The nymph usually have the same feeding habitat and resemblance with adults.

17. Exopterygota orders: • Notoptera(ice-crawlers & gladiators) • Plecoptera(stoneflies) • Embioptera(webspinners • Zoraptera(angel insects) • Dermaptera (earwigs) • Orthoptera (grasshoppers, etc) • Phasmatodea(stick insects) • Blattaria(cockroaches) • Isoptera(termites) • Mantodea (mantids) • Psocoptera (booklice, barklice) • Thysanoptera (thrips) • Phthiraptera(lice) • Hemiptera (true bugs) • Odonata (dragonflies)

18. Order Orthoptera: • Ortho = straight, ptera = wings. Hence these are insects with straight wings. • Include (grasshoppers, crickets & katydids). • Have incomplete metamorphosis. Nymphs look similar to mature adults, but lack fully-developed wings.

20. Characteristics • Mandibulate , chewing mouthparts. • Antennae have multiple joints, and are of variable length. • Compound eyes. • The first and third segments of the thorax are enlarged, while the second segment is much shorter. • The final two to three segments of the abdomen are reduced, and have single-segmented cerci. Have a generally cylindrical body.

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22. They have two pairs of wings, which are held overlapping the abdomen at rest. • The forewings, or tegmina, are narrower than the hind wings and hardened at the base, • While the hind wing is membranous, with straight veins and numerous cross-veins. At rest, the hind wings are held folded fan-like under the forewings.

23. Usually enlarged hind femora/hind legs for jumping. • Most are medium to large. • This form of sound production is called stridulation, and involves rubbing the upper and lower wings or the hind leg and wing together to create a vibration.

25. Distinctive feature: • Hind legs adapted for jumping. Tympanum (sound markers present). • Have long ovipositor and long pronotum. • Exist in terrestrial habitats. • Very destructive to crops

27. Examples • Grasshoppers

28. Crickets

29. Katydids

30. Order Odonata: • Odonto’ refers to strong teeth on mandibles of adults. • Includes dragonflies and damselflies. • Incomplete. Nymphs and adults different in appearance. • nymphs with gills called naiad. Indicate good water quality. • Adults nearly water or terrestrial. Adults are moderate to large predaceous insects. • Hemimetabolous: egg -> nymph (naiad) -> adult

31. The mouthparts underside of head and simple chewing mandibles. • Have two ocelli and short antennae. • Two pairs of long, transparent wings that move independently. Abundantly veined. • Elongated abdomens. • Big compound eyes. Excellent vision; can rotate head almost 360 to capture the pray. • Long slender bodies. Have large rounded heads

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33. Distinctive features: • Long needle like abdomen, prominent eyes, antennae short and setaceous • Habitat almost all in lentic waters. • Beneficial (predaceous on mosquitoes and other insects).

34. Examples • Dragonflies

35. Damselflies

36. Order phasmida: • The order name comes from the Greek word phasma, meaning apparition. Some entomologists call this order Phasmatodea. • The order Phasmida includes some of the best camouflage artists in the insect world - the stick and leaf insects.

37. Nymphs and adults similar in appearance. simple metamorphosis. • Eggs are laid, often dropping to the ground, as copulation takes place. • In some species, females can produce offspring without fertilization by a male. • These offspring are nearly always female, and males of those species are rare or non-existent.

38. Chewing mouthpartsdesigned for breaking down plant material. • Antennae are long and slender. • Prothorax is short. Mesothorax & Mesothorax are very elongated. • Leathery, elongate bodies and long thin, slender legs designed for walking slowly. • None. Rarely 2 pair leaf like.Forewing very narrow and tough (=tegmina); hindwing membrane-like & folded; N. American species lack wings. • Large 12-178mm.

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40. Distinctive features • Elongated, cylindrical bodies, pencil like or stick like, slow moving. • Foliage feeders on trees and shrubs.

41. Examples • Stick insects:

42. Leaf insects:

43. References: • http://insects.about.com/od/flyinginsects/p/char_pterygota.htm • http://www.amentsoc.org/insects/fact-files/orders/pterygota.html • http://www.answers.com/topic/exopterygota-