Insecta Class Overview

Excretion and Anatomy of Insects

• Excretion occurs via green glands or Malpighian tubules.
• Insects typically exhibit sexual dimorphism with separate sexes.
• Internal fertilization and developmental metamorphosis characterized insect reproduction.
• Class: Insecta (Hexapoda) - air-breathing, predominantly terrestrial, some aerial, rarely aquatic.
• Body division into three main parts: head, thorax, and abdomen.
• Head features various mouthparts for chewing, biting, piercing, sucking, siphoning, or sponging.
• Thorax consists of segments with a pair of jointed legs and two pairs of wings.
• Abdomen composed of 7-11 segments; respiration facilitated by tracheae.

Sub-class Pterygota and Division Endopterygota

• Sub-class Pterygota: wings typically present; abdomen lacks appendages except for genitalia and cerci.
• Metamorphosis can be simple or complex.
• Division Endopterygota: wings develop internally and undergo complete metamorphosis, including a pupal stage.

Order Hymenoptera

• Characterized by social and parasitic insects.
• Modified mouthparts for biting and sucking; two pairs of wings with reduced veins.
• Defense mechanisms primarily through stings; workers possess stings, while drones do not.
• Queen honey bee has a vestigial sting.
• Larvae are legless (apodus) with exarate pupae (legs not appressed).

Honey Bees: A Historical Perspective

• Honey bees have been associated with humans since prehistoric times, documented in ancient texts like the Vedas, Ramayana, and Quran.
• Their significance in ancient civilizations is reflected in art, coins, and burial sites.
• Used strategically in warfare, honey bee swarms historically hindered enemy movements during WWI in Belgium.
• Bee venom recognized for its medicinal properties, aiding in pain relief and treatment for rheumatism and arthritis.

Beekeeping Development

• Primitive beekeeping methods have existed globally; advancements began with the movable frame hive invented in 1851 by Rev. L.L. Langstroth.
• Introduction of modern beekeeping to India occurred in Bengal (1882) and Punjab (1883).
• Systematic beekeeping initiatives began in Pusa, Delhi (1907-1919), expanding to the South in 1911.
• By 1928, the Royal Commission on Agriculture recommended beekeeping development as a cottage industry, promoting its growth in India.

Systematic Classification of Honey Bees

• Phylum: Arthropoda - includes jointed-legged, segmented animals with a chitinous exoskeleton.
• Open blood vascular system; respiration via gills, tracheae, or book lungs.
• Super-family: Apoidea - encompasses social bees and caste differentiation; female antennae have 12 segments, males 13.
• Family: Apidae - moderate-sized bees, with females collecting pollen in specialized baskets.
• Sub-family: Apinae - minute to moderate-sized bees living in large eusocial colonies.
• Tribe: Apini - true or stinging honey bees, including species introduced globally.

Honey Bee Species

• Genus: Apis - includes notable species such as A. dorsata, A. florea, and A. cerana indica.
• A. dorsata produces the highest honey yield among Indian species.
• A. indica (Indian Hive Bee) prefers dark nesting sites and is adapted to artificial hives.
• A. florea (Little Bee) builds small combs in open areas and has a limited altitude range.

Honey Bees' Habits and Habitat

• Highly organized social insects, active year-round but exhibit limited activity in winter.
• Springtime is crucial for brood rearing and honey collection.
• Colonies communicate through sign language and exhibit polymorphism.
• Major honey-producing species, like Sarang bees, yield significant quantities of honey (up to 25 kg per comb) and support extensive pollination efforts.
• A. indica is adaptable for beekeeping; A. florea remains more spontaneous in nesting behavior.

Explore the fascinating features of the Insecta class, focusing on their unique excretion methods, sexual dimorphism, and the process of metamorphosis. This quiz will help you understand the air-breathing, mostly terrestrial lifestyle of insects and their reproductive strategies.