Glandular system

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Dr. T. KRISHNA CHAITANYA
Assistant Professor (Agricultural Entomology)
School of Agricultural Science & Technology, NMIMS, Shirpur
ENTO 131 - Fundamentals of Entomology (3+1)

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Glandular system

3. • Glandular system is otherwise called as secretary system and is
divided in to two major groups based on the presence or absence of
ducts.
A. Exocrine glands (glands with duct)
B. Endocrine glands (glands without duct)
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4. 1. Salivary glands: Salivary glands are modified labial glands which
secrete saliva and open beneath hypopharynx.
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5. 2. Mandibular glands: Secrete saliva in caterpillars when salivary
glands are modified into silk glands. In queen bee it secretes queen
substance.
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6. 3. Maxillary glands: Secretions are useful to lubricate mouth parts.
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7. 4. Pharyngeal glands: Secrete bee milk or royal jelly in nurse bee.
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8. 5. Frontal glands: Secrete sticky defensive fluid in nasute termites.
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9. 6. Setal glands: Glandular seta (Scoli) secrete irritant fluid in hairy/slug
caterpillar.
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7. Tenant hairs: Secrete sticky fluid found in pulvilli of legs and helps
in ceiling walking in house flies.

11. 8. Moulting glands: Modified glandular epidermal cells, secrete
moulting fluid necessary for moulting
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12. 9. Stink glands (Repugnatorial glands): Secrete bad smelling substance.
e.g. Stink bugs, bed bugs.
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13. 10. Osmeteria (Forked gland): Eversible gland in the head of Papilionid
larva with defense function. e.g. Citrus butterfly larva.
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14. 11. Androconia (Scented scales): Secretions of glandular scales of male
pierid butterflies to attract the opposite sex.
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15. 12. Pheromone glands: Found in abdominal terminalia of one sex and
its secretions are released outside to attract opposite sex of the same
species.
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16. 13. Wax glands: Dermal glands producing wax in bees and mealy bugs.
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17. 14. Sting glands: Modified accessory glands secreting venom in worker
bees and wasps.
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18. 15. Lac glands: Dermal glands secreting resinous substances in lac
insect.
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19. 16. Milk glands: Modified accessory gland nourishing larva developing
in uterus. e.g. Sheep ked.
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20. B. Endocrine glands (glands without duct):
1. Neurosecretory cells (Brain hormone or bursicon,
Prothoracicotrophic, Gonadotrophic, diuretic, hyperglycemic
2. Corpora cardiac – Neurohaemal organs
3. Corpora allata – Juvenile hormone or Neotenin
4. Prothoracic glands – Ecdysone or Moulting Hormone
5. Weismann's ring
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