S.Y. Practicals

All notes for the Second year, B.Sc. 
(Pune University) Practicals

Scoliodon arterial system dissection, showing innominate artery

Practical No.:21 (A)

Aim: To study life cycle of Honey bee.

The honey bee is holometabolous insect. The queen is functional female. The life cycle consists of egg, larva, pupa and adult.

Egg:

-          Egg laying starts after 3 days of copulation. The eggs are pinkish, elongated, and cylindrical in shape.

-          Fertilized eggs develop into queen and females and an unfertilized egg develops into males.

Grub:

-          The larvae are minute, white, apodous and with no eyes.

-          Type of food supply determine the caste

-          For the first 3 days all the larvae are fed on royal jelly which is produced by pharyngeal gland of young workers.

-          After 3 days, worker and drone bee larvae are fed on mixture of honey and pollen called bee bread.

-          Larvae of queen are continuously fed on royal jelly.

-          The grub grow and moult several times, then cells are sealed with a wax cap.

Pupa:

-          The pupa is exarate type i.e. the legs are free not adhered to the body.

-          After the pupal period is over the sealed pupae becomes tan and finally light brown in colour  and the lid of cell is cut-off by the young bee, with jaws.

-          After few hours later the pupal cuticle breaks and the adult be emerges out.

Adult:

-          The emergence of adult takes place after 3 weeks.

-          The emerged adult chew away the cell cap and crawls out to join the other bees as a member of the hive.

Morphological feature of three caste of a honey bee

Sr. No.	Drone	Worker	Queen
1.	Eyes meet over head	Eyes far apart	Eyes far apart
2.	Abdomen black, rectangular, blunt and without sting	Abdomen stripped, triangular with barbed sting	Abdomen is golden or black, triangular and more elongated.

v Periods of development of different castes of honey bees

Duration in days
Caste	Egg	Larva	Pupa	Total
Queen	3	5	7-8	15-16
Worker	3	4-5	11-12	18-20
Drone	3	5-7	13-14	21-24

Practical No.:21 (B)

Aim: Study of mouth parts, thoracic appendages (legs and wings)

         and sting apparatus of Honey bee

v Mouth parts of honey bee: The mouth parts are biting and sucking type. It consists of labrum, epipharynx, mandibles, maxillae and labium.

-          Labrum: Large plate attached to lower margin of clypeus.

-          Epipharynx: It lies below the labrum. It is organ of taste.

-          Mandibles: They are in pair and lies on either  side of the labrum. Mandibles are equipped with abductor and adductor muscle. Mandibles are useful to gather pollen and mould the wax. Mandibles of worker are spoon shaped, thick at the base and narrowed through the middle.

-          Maxillae: It lies beneath mandibles. The lacinia is absent,  maxillary palps are vestigial and the galea is elongated and blade-like.

-          Labium: Paraglossae are reduced but the glossae are very much elongated, united, hairy and form a honey-spoon called labellum at the terminal part.

At the time of nectar feeding, the labium and maxillae come together to form sucking tube.

v Thoracic appendages: Thorax bears two pairs of wings and three pairs of legs.

Wings:

-          The wings are small, narrow, membraneous and transparent.

-          Pair of wings lie flat over the back at rest.

-          Forewings are larger than hindwings.

-          Main function is flight but also used to cool the hive.

-          Forewings and hindwings are interlocked by hooks (hamuli) so both the wings can work together during flight. 

 

Legs:

-          There are 3 pairs of legs, i.e. prothoracic, mesothoracic and metathoracic.

-          They show progressive increase in length from 1^st to 3^rd pair.

-          Each leg consists of coxa, trochanter, femur, tibia and tarsus.

-          Tarsus is five jointed and ends into the claws and pulvillus.

a.      Prothoracic leg:

-          Anterior face of tibia bears many stiff bristles which forms pollen brush.

-          Posterior face of tibia bears have movable plate-like process called velum, which fits over a circular notch in the upper part of the 1^st tarsal segment.

-          The velum and antenna comb together forms antenna cleaners.

-          Eye brush present on the anterior surface of the first tarsal segment is used for removing pollen and other particles from the surface of the compound eyes.

b.      Mesothoracic leg:

-          The tibial segment bears a brush on its inner surface and a spine-like pollen-spur on its distal end.

-          The spurs are used to remove pollen from the pollen baskets of hind-legs and to dislodge wax from wax pockets on the ventral surface of the abdomen.

c.      Metathoracic leg:

-          It has a large tibia with a cavity having bristles forming a pollen basket, used for storing pollens during collection.

 

Sting apparatus of honey bee:

-          The posterior part of the worker bee’s abdomen is modified into sting apparatus and wax gland on ventral surface of abdomen.

-          In the worker bee the ovipositor changes so as to take the function of sting i.e. for injecting poison. The sting apparatus has three components namely, the sting, the plates and poison gland.

The sting:

-          It is a hollow organ formed by three pieces bounding a central canal. The dorsal part is the stylet sheath, and the two ventral pieces are stylets or lancets

-          The apices of the stylets and their sheath bear forwardly directed barbs.

-          The stylet sheath expands at its bas to form the bulb of the sting and latter a pair of diverging arms.

The plates:

-          3 pairs of plates associated with the sting act as a lever.

-          The innermost pair of oblong plates posterior in position and representing the divided 9^th sternum.

-          Two triangular or fulcra plates representing reduced 8^th sternum and attached to corresponding styles.

-          The large quadrate plates lie dorsally to the triangular plates and at the posterior angle.

Glands:

a.      Acid gland: it is elongated, slender gland open into the upper end of the poison sac. It discharges an acidic secretion into the sac.

b.      Alkaline gland: it is thick, tubular gland which opens externally below the base of the bulb.

PEST OF STORED GRAINS (Rice weevil and Pulse beetle)

RICE WEEVIL

Class — Insecta

Order — Coleoptera

Family — Curculionidae

Genus — Sitophilus

Species — oryzae

This is a very serious pest of stored grains as well as grains in farm storage. It is cosmopolitan in distribution.

Fig: Rice weevil and Pulse beetle

Nature of damage:

Generally infestation starts in grains only during storage. The S. oryzae feeds on whole grains of rice, wheat, jowar, bajri, maize, barley etc. Both adults and larvae feed voraciously on the grains so that the grain becomes unfit for consumption and seed purposes. A thin tunnel (hole) is formed by the grub from the surface towards inside of the grain. Circular exit holes and stained spots on the surface of the grain kernel is the symptom of damage. In case of heavy infestation, the grains become a mass of broken vegetable matter. The adults eat a small amount of grain, making shallow holes with rugged edges but the amount of damage thus caused is negligible as compared to the complete hollowing of grain by the larval stages results into hollowed grains leading to reducing in weight and food value.

Pulse Beetle : Callosobranchus (= Branchus) chinensis, Linn

Class Insecta

Order coleoptera

Family Bruchidae

Genus Callosobranchus

Species chinensis

Popularly known as pulse beetle, it is a native of china but is a serious pest of all type of pulse in all parts of India . Pest is reported on almost all kind of pulses like mung, peas, caw pea and gram.

Damage: Callosobranchus chinensis is vary serious stored grain pest, causing enormous damage to almost all kinds of pulse grains. The developing larvae mainly cause damage to the pulse grain. Just after hatching young larvae bores into the grain, feed upon the contents of the grain making them almost hollow and empty.

Control Measures:

1. Preventive Method:

After harvesting, dry the grains in sunlight sufficiently so that the moisture content is reduced to less than 8% moisture.

After drying in sunlight, the grains store in new gunny bags.

Use of neem leaves, mercury, mixing of ash, powder of sweet flag rhizome (Acorus Calamus Linn), etc. in grains or smearing the grains with plant oils.

old bags should be fumigated with EDBR (Ethylene di-bromide) at 3 kg/100 cu.m. for 5 to 7 days.

2. Curative Measures

This measure becomes essential when the grains get infested with the stored grain pests.

(i) Sieving and cleaning removes all the stages of pests.

(ii) After above method the grains must be followed by sunning and fumigation with suitable fumigants.

(iii) The larvae and adults are killed by exposing them for 48 hours to the vapours of ethylene dichloride - carbon tetrachloride mixture under gas-proof covers. Fumigation of infested grain with methyl bromide is also effective and kills all stages of the pest including eggs.

Citrus or Lemon Butterfly (Papilio demoleus) :

Popularly known as lime swallowtail, or citrus swallowtail.

Distribution: his species is found throughout tropical and subtropical regions of southern Asia to India.

Fig: A) larva, B) Pupa C) adult

Nature of damage:

It is the most destructive pest in nurseries. The caterpillars feed on the young foliage at the nursery stage and also on young flushes of grown up trees. The caterpillar feed voraciously on leaf lamina leaving behind only the midrib. In case of severe infestation, entire tree is defoliated. The fully grown caterpillars are green in colour.

Control : Hand picking of the larvae and

Chemical control: spraying with Endosulphan 35 EC (2ml/10 litres of water)

is effective in controlling the pest.

Biological control: Three parasitoids are known to parasitize P. demoleus larvae in India. They are Apanteles (=Ooencyrtus) papilionis, Apanteles sp. and Bracon hebetor (Hymenoptera: Braconidae).

The biopesticides Bacillus thuringiensis and Beauveria bassiana, as well as neem seed kernel extract and azadirachtin were shown to have effects on P. demoleus in India. Bacillus thuringiensis showed the highest effect.
Other natural methods of control. Larvae are easily hand-picked from nursery plants, but this practice is labor intensive if infestation is high.

2. BLISTER BEETLE (FLOWER BEETLES)

Class — Insecta
Order — Coleoptera
Family-- Meloidae
Genus - Mylabris
Species - pustulata (Thunberg)

Nature of Damage:

Beetles attack inflorescence and feed on pollens and petals of flowers and adversely
affecting grain setting. In case of severe infestation earheads without grains are seen in
the field due to hindering fertilization.

Control Measures:

1. Collection of beetles by hand, insect nets, or
2. They may be attracted by light traps then killed in kerosin water.
3. Dusting 10% BHC at the rate of 25 kg/hectare is effective in controlling the
   pest.
4. The population of adult beetles can be effectively suppressed by spraying
   emulsion of any one of the following insecticide.

Insecticide	Conc. (%)	mi/litre of water
Chiorpyriphos (Dul-sban) - 20 EC	0.025	1.25
Quinalphos (Ekalux) - 25 EC	0.05	2.0
Phosalone (Zolone) - 35 EC	0.05	1.5

STAR FISH ( Asterias rubiens )

STAR FISH ( Asterias rubiens)
Phyllum = ECHINODERMATA
Class= ASTEROIDEA
Order= FORCIPULATA
Genus= Asterias
Species= rubiens

Habitat :- free living marine animal
Shape :- Star shaped
Symmetry :- pentamerous radial symmetry
Colour :- yellow, pink or purple
Exoskeleton :- numerous calcareous ossicles
Coelom :- true coelom
Feeding :- Carnivorous Vascular system:- Water vascular system
Circulatory system :- Open type
Respiration :- dermal branchiae or papulae
Excretion:- By amoeboid corpuscles
Sense organ:- neurosensory cells and eyes
Reproductive system :-
  Unisexual or dioecious
Fertilization :- External
Development :- Indirect
# Body consist of indistinct central disc
# tapering arms or rays
# dorsoventrally body
# upper surface called aboral (convex ) and lower surface oral ( Flat)
# oral surface have central disc having mouth
# mouth surrounded by soft membrane called peristome membrane
# upper convex surface, covered with stout and immovable calcereous spicule, between this small soft, papullae or Gill, which respiratory in function
# Epidermis :-
    

Consist ciliated columnar cells and neurosensory cell, epidermis covered externally two layered thin cuticle
# Dermis:-
    Thicker,  mesodermal origin, composed fibrillar connective tissue
# Muscular root:-
    Made up of smooth muscle fiber
# Coelomic epithelium :-
   Lining with coelom, consist cuboidal ciliated cell called parietal peritoneum
# Mouth:-
    At oral surface,  surrounded by peristome membrane,  guarded by sphincter muscle
# Oesophagus:-
   Shory Tube open in stomach
# Stomach :-
    Having
i) cardiac stomach :-
       Pentagonal Sac, capable of being everted outside
ii) Pyloric stomach :- 
     Small, flat pentagonal Sac open above into intestine
# Intestine :-
     Five sided tube extending vertically to aboral surface
# Anus:-
    Small rounded aperture somewhat eccentrically
# Digestive gland :-
In star fish called pyloric caecum,  each of them consists of glandular pouches, pyloric caecum formed four flagellated columnar cell
i) Flagellated cell
ii) Secretory cell
iii) Mucous cell
iv) Storage cell
# Circulatory system in starfish called haemal system, open type, consists thin inter-communicating channels filled with coelomic fluid
@ Oral haemal ring:-
         Circular haemal sinus
@ Radial haemal sinuses :-
        Gives off five haemal sinuses into arms
@ Axial gland :-
      Also called heart or brown gland, having elongated fusiform
@ Aboral haemal ring :-
     Pentagonal ring canal lying beneath aboral surface
# Nervous system:-
      Very simple and primitive connected by skin except visceral nerve plexus
Having four part
1) Superficial System :-
        Situated below epidermis consists of

Circumoral nerve ring
- Radial nerve cord
- Sub-epidermal plexus
2) Deep hyponeural nervous system:-
   Radial nerve and radial ambulacral vessel of each arm
3) Aboral nervous System :-
    Situated in aboral body wall, outside pariental peritoneum
4) Visceral nervous System :-
   Located in wall of gut just outside enteric epithelium
# Neurosensory cells :-
       Present throughout epidermis, it is of two type tactile around tube feet and olfactory Around mouth
# Eye :-
    Five small, bright red eye spot under base of tentacle
# Gonads:-
   A pair in each arm, each gonad elongated branched body
# Fertilization :-
  Take Place In spring appears induced by rising spring temperature
# Development :-
   Indirect, egg undergo rapid, equal and indeterminate cleavage

# Regeneration :-
    Power to reform lost body part,