Want to know the reproductive system of insects? Check this!

1. Reproductive System in Insects.
AEN 201 Fundamentals Of Entomology.
Course Mentor: Dr Pretheep Kumar
Expounded by:
Chandini S
2013-009-005
II B.Sc.(Sericulture)

2. &The reproductive organs of insects are similar in
structure and function to those of vertebrates.
&Both types of gametes are haploid and unicellular,
but eggs are usually much larger in volume than
sperm.
&Most insect species reproduce sexually by internal
fertilization.

3. Functions of the Reproductive
System:
Male:
&Production of sperm.
&Storage of sperm.
&Delivery of sperms to the
female.
Female:
&Production of eggs, including yolk
and chorion formation.
&Reception and storage of sperm
(may be for long times).
&Coordination of events that lead to
fertilization and oviposition.

4. Male Reproductive System:
&Testes - Usually near the back of the abdomen.
&Each testes is subdivide into functional units - Follicles - sperm
is produced.
&At the distal end of each follicle-group of germ cells -
Spermatogonia.
&Spermatogonia - divide by mitosis - Increase in size to form
Spermatocytes.

5. &Spermatocytes - migrate toward the basal end of the follicle.
&Spermatocytes – undergo meiosis – yields 4 haploid spermatids.
&Spermatids – develop into mature spermatozoa.
&One or more pair of accessory glands – usually associated with
male’s reproductive system.
&2 major functions of accessory glands:
Manufacture of seminal fluid.
Production of spermatophores.

6. &Mature sperm pass out of the testes through short
ducts – Vasa efferentia.
&Collected in storage chambers – Seminal vesicles.
&Similar ducts – Vasa deferentia – from the seminal
vesicles – join together near the body mid line –
form a single Ejaculatory duct – leads out of the
body through copulatory organ – Aedeagus.

8. Female Reproductive System:
&A pair of ovaries.
&Each ovary - subdivided into functional units – Ovarioles –
Eggs are produced.
&Near the distal end of each ovariole – group of germ cells –
Oogonia – divide by Mitosis.
&Oogonia – increase in size to form Oocytes.
&Each oocyte – undergoes Meiosis – yields 4 cells – 1 egg and 3
polar bodies.

9. &Polar bodies may disintegrate or they may accompany the egg as nurse
cells.
&Developing eggs move down the ovariole – grow in size by absorbing
yolk.
&Mature eggs leave the ovaries through short Lateral Oviducts.
&Near the body midline – lateral oviducts join to form a common oviduct
– opens into a genital chamber – Bursa Copultrix.
&Female accessory glands – supply lubricants for the reproductive system
and screte a protein-rich egg shell – Chorion.
&Accessory glands – usually connected by small ducts to the common
oviduct – Bursa Copultrix.

11. Processes:
&Copulation – The male deposits its spermatophore in the bursa
copultrix.
&Peristaltic contractions force the spermatophore into the female’s
spermatheca.
&Spermathecal gland – Produces enzymes and nutrients.
&Ovulation – Each egg passes across the opening to the
spermatheca – stimulates release of a few sperm onto the egg’s
surface.

12. &Fertilization – Occurs as soon as one sperm’s
nucleus fuses with the egg cell’s nucleus.
&Oviposition – Egg laying – usually follows closely
after fertilization.
&After the completion of all the processes – the egg
is ready to begin embryonic development.

13. Oviparity:
&Egg laid shortly after
fertilization.
&No retention
&No nutrients to embryo
after fertilization.
&Eggs retained.
&Embryo fed by mother.
&Immature may
complete development
before deposition.
Viviparity:

14. Types of Reproduction:
& Paedogenesis – Reproduction by larval insects.
& Parthenogenesis – Developments without fertilization –
Unfertilized eggs produce – Males, Female, Or Both.
& Polyembryony .
Mating:
& Females of some species – essentially Monogamous – mate only
once.
& Most female insects – Polygamous - mate several to many times.

15. CITATION:
“The Reproductive System of Insects”
Dr Arwa Elaagip,
Department of Parasitology and Medical
Entomology,
University of Kartoum.

16. Thankieyeww