The document summarizes the male and female reproductive systems of insects. The male system includes testes, vas deferens, seminal vesicles, an ejaculatory duct, and accessory glands. The aedeagus is the male copulatory organ through which sperm is secreted. The female system includes ovaries with ovarioles, oviducts, accessory glands, a spermatheca for storing sperm, and a vagina or bursa copulatrix for receiving sperm and discharging eggs. The document provides details on the structures and functions of these organs.

1. Lecture no. 13
Structure of male and female genital organ
R K PANSE
Assistant Professor
Entomology
Lecture no. 22
Structure and functions of male and female
Reproductive system

2. Lecture no. 22
Structure and functions of male and female
Reproductive system
 In insects male and female sexes are mostly separate.
 Sexual dimorphism is common where the male differ from
the female morphologically as in bees, mosquito and
cockroach. The other types are:
 Gynandromorph: (Sexual mosaic) Abnormal individual
with secondary sexual characters of both male and female.
e.g. mutant Drosophila.
 Hermaphrodite: Male and female gonads are present in
one organism. e.g. Cottony cushion scale.

3. Male Reproductive system

4. Male reproductive system
Internal male reproductive organs consists of
•a pair of testis,
•a pair of vasa deferens,
•seminal vesicle
•ejaculatory duct
•accessory glands a) mesodenia b) ectodenia and
•Genitalia organs

5. Testis: The size of testis is
practically same as that of
ovaries in Apterygota and
very much smaller in
Pterygota. They lie in visceral
cavity above the alimentary
canal and are connected to
the body wall through
translucent ducts and are well
supplied with trachea and fat
body tissues. Each testis
consists of number of oval
shaped structures known as
follicles.
Function: production of
sperms

6. Vasa deferens: These are
the long tubes formed by the
union of vasa efferens which
receives the sperms from
testis and allow their
transport to the ejaculatory
duct.
Seminal vesicles: Each vasa
deferens become enlarged
posteriorly to form a sac like
structure called seminal
vesicle for storage of
spermatozoa for some time.

7. Ejaculatory duct: Both the vasa
deferens of the two testis unite
posteriorly to form a common
median ejaculatory duct. The
terminal section of ejaculatory duct
is enclosed in a finger like
evagination of body wall, male
copulatory organ or aedeagus.
Accessory glands: These are 1-3
pairs of glands which open in to the
ejaculatory duct. In most cases their
secretion mix with spermatozoa.
These glands are called mushroom
glands in cockroaches and mantids
because of their appearance as
mushrooms. This secretions
facilitates sperm transmission from
male to female.

8. Structure of male genital organ
An aedeagus (plural aedeagi) is a reproductive organ of
male arthropods through which they secrete sperm from
the testes during copulation with a female. Very loosely, it can be
thought of as the insect equivalent of a mammal's penis, though
the matter is actually more complex.
The aedeagus is part of the male's abdomen, which is the
hindmost of the three major body sections of an insect. The pair
of testes of the insect are connected to the aedeagus through the
genital ducts. The aedeagus is part of the male insect's phallus, a
complex and often species-specific arrangement of more or less
sclerotized (hardened) flaps and hooks which also includes in
some species the valvae (clasper), which are paired organs which
help the male hold on to the female during copulation. During
copulation, the aedeagus connects with the ovipore of a female.

9. clasper
aedeagus
phallotheca

10. The base of the aedeagus may be the partially sclerotized
phallotheca, also called the phallosoma or theca. In some
species the phallotheca contains a space, called the endosoma
(internal holding pouch), into which the tip end of the aedeagus
may be withdrawn (retracted). The vas deferens is sometimes
drawn into (folded into) the phallotheca together with a seminal
vesicle.
The sperm of arthropods is not passed to the female as liquid
with free-swimming spermatozoa, but contains capsules
called spermatophores in which the actual spermatozoa are
enclosed. In addition to the spermatophores, in some species the
aedeagus also discharges a spermatophylax, a ball
of nutritious secretions to aid the female in producing offspring.

11. Female Reproductive system

12. Female reproductive system consists of
•a pair of ovaries which possess number of ovarioles,
•a pair of oviducts,
•common oviduct / Median oviduct ,
•a pair of accessory glands and
•Bursa copulatrix or copulatory pouch or genital
chamber or vagina
•spermatheca

13. Ovaries: These are the prominent visceral organs present on
the either side of alimentary canal. Anteriorly the ovaries get
connected with the body wall by means of thread like
suspensory ligaments. The ovaries are covered with fat body
and are richly covered with trachea. Each ovary consists of a
no of ovarioles or egg tubes.
Ovarioles: Each ovariole is enveloped by a double layered
cellular wall . The outer wall is called ovarial sheath which
has an abundant supply of tracheae. The inner layer called
tunica propria is elastic in nature. Each ovariole at its
terminal has a filament.

14. Types of ovarioles :
Based on the presence or absence of nutritive cells and their
location ovarioles are categorized in to two:
1. Panoistic ovarioles: In these, the nutritive cells are absent
and the development of oocytes takes place with the help of
follicular epithelial cells e.g.: Odonata, Dictyoptera,
Orthoptera and Ephemeroptera
2. Meriostic ovarioles: They contain trophocytes / nutritive
cells which vary in their position.
Based on the position of trophocytes Meriostic ovarioles are
classified into
(i) Polytrophic ovarioles: where developing oocyte and
trophocytes arranged alternatively within the vitellarium. e.g.:
Mecoptera, Dermaptera, Psocoptera
(ii) Acrotrophic ovarioles: Also called teletrophic ovarioles
where the trophocytes are present in the germarium (apex)
and are connected with the growing or developing oocytes by
cytoplasmic strands. e.g.: Hemiptera and Coleoptera

15. Lateral oviducts: Proximal end of the ovarioles of each ovary join
to form a lateral oviduct on each side .The wall of oviduct is
glandular and muscular
Median Oviduct: Two lateral oviducts combine to form a median
oviduct
Accessory glands: These are a pair of collateral glands which open
in to the distal portion of vagina and secrete the substance
responsible for the formation of ootheca of cockroach, preying
mantid and poisonous secretions in case of Hymenoptera. This
sticky substances are useful for attachment of egg to the substrate.

16. Spermathea: It is a sac like structure consisting of a spermathecal
gland and opens in to vagina through spermathecal duct. This is
mainly used for storing the sperms. It also produces some fluids
responsible for longevity of cells for several hours.
Vagina: In most of the insects median oviduct doesnot open directly
to outside. It opens in to a tubular genital chamber or vagina formed
by invagination of bodywall from VIII segment . The vagina opens
outside and the opening is called vulva. Vulva serves both purposes
of receiving the sperms and discharging the eggs.

17. Structure of female genital organ
Genital chamber (Bursa Capulatrix/Vagina), Two types of
ectodermal glands open into the genital chamber.
 The first is the spermatheca which stores spermatoza until they
are needed for egg fertilization. The spermatheca is single and sac-
like with a slender duct, and often has a diverticulum that forms a
tubular spermathecal gland. The gland or glandular cells within the
storage part of the spermatheca provide nourishment to the
contained spermatozoa.
 The second type of ectodermal gland, known collectively as
accessory glands, opens more posteriorly in the genital chamber.
Each ovary is composed of a cluster of egg or ovarian tubes, the
ovarioles, each consisting of a terminal filament, a germarium, a
vitellarium and a pedicel. An ovariole contains a series of
developing oocytes each surrounded by a layer of follicle cells
forming an epithelium, the youngest oocytes occur near the apical
germarium and the most mature near the pedicel.

18. Bursa Copulatrix: In some insects the genital chamber or vagina
develops a separate pouch called Bursa Copulatrix in to which
insects have two reproductive openings . One is vulva for receiving
the sperms open on VIII sternum and another one is ovipore or
gonopore on IX segment for discharging eggs. Eg: Lepidoptera and
water beetles.

19. The Bursa Capulatrix -The organ to to receive the penis and
associated parts during copulation, the spermatozoa being
discharged into it before entering the spermatheca. The bursa is
formed by the invagination of the body wall around the genital
aperture and consequently receives the latter anteriorly.