3. Types of insect heads and antennae.pptx

Insect head is a Anterior most part of insect body it is hard and highly sclerotized compact structure which consisting of six segments that are fused to form a head capsule. The insect head consists of mouthparts, compound eyes, simple eyes (ocelli) and a single pair of antennae.

1. Types of insect heads and antennae Dr. L. RAMAZEAME Ph. D Assistant professor Agricultural Entomology SRMCAS,SRMIST

2. Based on the inclination of long axis of the head and orientation of mouth parts there are three types of insects heads. Characters Types of head Hypognathous: (Hypo-below ; gnathous -jaw) or Orthopteroid type. 2. Prognathous: (Pro- infront ; ganthous -jaw) or Coleopteroid type 3. Opisthognathuos : ( Opistho-benind ; gnathuos -jaw) or Hemipteroid type or Opisthorhynchous type. The long axis of the head vertical, horizontal. deflexed. Mouth parts. ventrally placed and project downwards directed forward. directed backwards and held in between the forelegs Example Grasshopper, cockroach. Ground beetle. stink bug.

3. Types of insect Head

4. Structure of insect antenna Feelers. Paired, highly mobile and segmented. Antennae are located between or behind the compound eyes. All insects except protura have a pair of antennae. Antennae are well developed in adults and poorly developed in immature stages . The antenna is set in a socket of the cranium called antennal socket. The base of the antenna is connected to the edge of the socket by an articulatory membrane . This permits free movement of antennae

5. The basal segment is called scape . It is conspicuously larger than succeeding segments. The second antennal segment is called pedicle which immediately follow the scape . A mass of sense cells called Johnston's organ is present in the pedicel, which is used as a chordatonal organ in some of the insects like mosquitoes . Both scape and pedicel are provided with intrinsic muscles. The remaining annuli or flagellomeres are known as flagellum or clavola which lack individual muscle. Surface of the flagellum is supplied with many sensory receptors that are innervated by the duetocerebrum of brain . Flagellum may very in size and form.

6. Functions Antenna is useful to detect chemicals including food and pheromones ( chemicals secreted into air by opposite sex). It perceives smell, humidity changes, variation in temperature, vibration, wind velocity and direction . Antenna is useful to perceive the forward environment and detect danger. It is useful for hearing in mosquitoes and communication in ants. Rarely it is also useful to clasp the mate (e.g. Flea) and grasp the prey.

7. Types of Antennae 1. Setaceous (Bristle like) e.g Dragonfly

8. 2. Filiform (Thread like) e.g Grasshopper

9. 3. Moniliform (Beaded) e.g Termite

10. 4. Serrate (Saw like) e.g Longicorn beetle

11. 5. Unipectinate (Comb like) e.g Mustard Sawfly

12. 6. Bipectinate (Double comb like) e.g Silkworm Moth

13. 7. Clavate (Clubbed) e.g Blister beetle

14. 8. Capitate (Knobbed) e.g Butterfly

15. 9. Lamellate (Plate like) e.g Dung roller / Lamellicorn beetle  

16. 10. Aristate e.g Housefly

17. 11. Stylate e.g. Robber fly

18. 12. Plumose (Feathery) e.g. Male Mosquitoes

19. 13. Pilose (Hairy) e.g Female Mosquitoes

20. 14. Geniculate (Elbowed) e.g Ant

21. 15. Flabellate (Fan like ) e.g Twisted –Wing Parasites/ Stylopids / Strepsitera

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