Entomology Module 3

Insect Physiology

1. Digestive system – divided into foregut, midgut, hindgut.
2. Foregut – ingestion, storage (crop), grinding (gizzard).
3. Midgut – digestion and absorption (no cuticle lining).
4. Hindgut – water and salt reabsorption.
5. Salivary glands – produce enzymes and silk (in caterpillars).
6. Blood (hemolymph) – colorless, no hemoglobin.
7. Insect heart – dorsal, tubular, pumps hemolymph anteriorly.
8. Hemocytes – defense and coagulation functions.
9. Respiration – tracheal system with spiracles, tracheae, tracheoles.
10. Tracheal system types – open, closed, and semi-open.
11. Aquatic insects use gills or air bubbles for respiration.
12. Excretion by Malpighian tubules – remove uric acid.
13. Excretory product – uric acid (uricotelic).
14. Fat body – stores energy, glycogen, and detoxifies.
15. Endocrine system – prothoracic gland, corpora allata, corpora cardiaca.
16. Prothoracic gland secretes ecdysone (molting hormone).
17. Corpora allata secretes juvenile hormone (JH).
18. Corpora cardiaca stores and releases brain hormones.
19. Nervous system – brain + ventral nerve cord + ganglia.
20. Sensory organs – sensilla (chemoreceptors, mechanoreceptors, photoreceptors).

Insect Ecology & Behavior

1. Insect ecology – study of relationship between insects and environment.
2. Population – group of same species in a given area.
3. Community – collection of populations in an area.
4. Ecosystem – interaction between living organisms and environment.
5. Biotic factors – living (predators, competitors).
6. Abiotic factors – non-living (temperature, humidity, light).
7. Diapause – genetically controlled dormancy.
8. Hibernation – winter dormancy.
9. Aestivation – summer dormancy.
10. Photoperiod – light duration influencing development.
11. Migration – long-distance movement (locust, armyworm).
12. Swarming – mass movement of insects.
13. Aggregation pheromone – used by bark beetles and locusts.
14. Alarm pheromone – released by ants and bees during danger.
15. Trail pheromone – used by ants for navigation.
16. Sex pheromone – for mating (used in pest monitoring).
17. Kairomone – benefits receiver but harms emitter.
18. Allomone – benefits emitter but neutral to receiver.
19. Synomone – beneficial to both species.
20. Intraspecific communication – among same species.
21. Interspecific communication – between different species.

Apiculture (Beekeeping)

1. Study of bees – Apiculture.
2. Family – Apidae; Order – Hymenoptera.
3. Major species – Apis dorsata, indica, A. mellifera, A. florea.
4. Bee colony – queen (1), drones (males), workers (females).
5. Queen bee – lays ~1500 eggs/day.
6. Drone – haploid, dies after mating.
7. Worker bee – sterile, does foraging, cleaning, nursing.
8. Worker bee lifespan – 6 weeks (summer).
9. Bee dance language – waggle dance and round dance (Karl von Frisch).
10. Queen substance – pheromone inhibiting development of new queens.
11. Royal jelly – secreted by worker’s hypopharyngeal glands, fed to queen larvae.
12. Swarming – natural method of colony division.
13. Bee products – honey, wax, royal jelly, propolis, bee venom.
14. Bee diseases – foulbrood, chalkbrood, nosema, acarine disease.

Sericulture (Silkworm Rearing)

1. Study of silk production – Sericulture.
2. Silkworm species:
   – Bombyx mori – Mulberry silkworm.
   – Antheraea mylitta – Tasar silkworm.
   – Antheraea assamensis – Muga silkworm.
   – Philosamia ricini – Eri silkworm.
3. Mulberry leaves – main food for Bombyx mori.
4. Cocoon – silk thread made of fibroin (core) and sericin (gum).
5. Reeling – unwinding silk from cocoons.
6. Diseases – Grasserie (virus), Flacherie (bacteria), Pebrine (protozoa).
7. Pebrine discovered by Louis Pasteur.
8. Silkworm egg laying – oviposition by female moth.