INSECT HEAD AND IT'S ORIENTATION

             INSECT HEAD AND IT'S ORIENTATION

         Based on the long axis of insect head and orientation of mouth parts, the insect head is classified into three types, 

                 1) HYPOGNATHOUS 

                 2) PROGNATHOUS

                 3) OPISTHOGNATHOUS 

1) HYPOGNATHOUS

     (Hypo – below; gnathous – jaw)

               * The long axis of the head is vertical.

               * The head is perpendicular to the long axis of body. 

               * The angle between the head and the body is right angle i.e, 90°.

               * The mouth parts are Vertically placed and it is projected downwards. 

               * This type is also called orthopteroid type. 

        EXAMPLE

                 Cockroaches. 

2) PROGNATHOUS

      (Pro- infront ; gnathous – jaw)

     

                * The long axis of the head is horizontal.

                * It is in straight line with the long axis of the body. 

                * Angle between the head and the body is 180°

                * Mouth parts are directed foreward. 

                * This type is also called coleopteroid type. 

       EXAMPLE

                   Ground beetle

 3) OPISTHOGNATHOUS

        (Opistho – behind ; gnathous – jaw)

                * Head is deflexed. 

                * The head is bent inwards and towards the body. 

                * The angle between the head and the body is 45°

                * Mouth parts are directed backwards and held between the forelegs. 

                * This type is also called hemipteroid type or opisthorhychous.

       EXAMPLE

                    Stink bug

Hello, everybody 

Here is a YouTube link regarding this blog , which facilitate you to with extra information and easy understanding. ☺👍

Insect head and it's orientation

 👉👉https://youtu.be/ptEuUu3VcYI

QUESTIONS TO PONDER

      1. ___________, _____________ and ____________ are three types of insect head. 

      2. Gnathous means _______________.

      3. The angle between the hypogethous head and the body is _______________ and it is also known as ____________.

      4. Hypo and opistho refers to ________ & _________.

      5. In opisthognathous, the head is _____________.

      6. Examples for hypognathous and prognathous head types are ___________&__________.

      7. ______________type of head is also called coleopteroid type.

      8. Opisthognathous head is also called as _____________.

      9. In ________________ type of head the mouthparts are directed backwards. 

    10. In prognathous, the head is in ___________ with the axis of the body.