ZOOLOGY

Sytematics is commonly defined as the study of biological diversity and the relationships among organisms. Taxonomy, that component of systematics specifically focusing on the theory and practice of classification, is not clearly separable and both are frequently used interchangeably by biologists. This chapter will first briefly review the importance of systematics to the pest management…

Taxonomy, in a broad sense the science of classification, but more strictly the classification of living and extinct organisms i.e., biological classification. The term is derived from the Greek taxis (arrangement) and nomos (law). Taxonomy is, therefore, the methodology and principles of systematic botany and zoology and sets up arrangements of the kinds of plants and animals in hierarchies of superior and subordinate groups. Among biologists the Linnaean system of binomial nomenclature, created by Swedish naturalist Carolus Linnaeus in the 1750s,…

The Earth can be divided into distinct regions based on the presence or absence of various organisms. These regions are known as realms. Over time, different scientists have proposed various classifications of these realms. In 1857, P. L. Sclater categorized the Earth’s geographical areas into six regions based on bird distribution. Later, in 1876, Alfred…

Barriers and dispersal are fundamental concepts in zoogeography, the study of the geographical distribution of animals. They influence how species spread, adapt, and evolve in different regions. Barriers in Zoogeography: Barriers restrict or prevent the movement of species, influencing their distribution. They can be classified into: a. Physical (Geographic) Barriers: Oceans & Seas: Prevent land…

Animal distribution refers to how animal species are spread across different geographical regions. The distribution of animals is influenced by factors such as climate, habitat availability, competition, predation, geological changes, and evolutionary history.Animal distribution can be classified into several types based on their geographical spread and limitations. Cosmopolitan Distribution: Species with a cosmopolitan distribution are…

Zoogeography is the branch of biogeography that studies the geographical distribution of animal species across different regions of the world. It helps in understanding how animals are distributed, their evolutionary history, and the factors influencing their dispersal. 1. Descriptive Zoogeography Descriptive zoogeography is a branch of zoogeography that focuses on systematically documenting and describing the…

Zoogeography is the branch of biogeography that studies the distribution of animal species across different geographical regions and the factors influencing their dispersal. It provides insights into how species originated, migrated, and adapted to different environments. Importance of Zoogeography • Helps in understanding species distribution and biodiversity. • Assists in conservation biology by identifying species-rich…

The sympathetic nervous system in cockroaches and Gryllus (crickets) belongs to their overall nervous system and is part of the visceral nervous system, responsible for controlling internal organs. Although insects don’t have a “sympathetic nervous system” identical to vertebrates, they have an analogous system referred to as the stomatogastric nervous system (SNS). Here’s a summary…

The red cotton bug (Dysdercus cingulatus), commonly found in cotton-growing regions, has specialized digestive and reproductive systems adapted to its diet of plant sap, primarily from cotton plants. Here’s an overview of each system: 1. Digestive System of the Red Cotton Bug The red cotton bug’s digestive system is adapted for sap-sucking, which involves piercing…

The butterfly has specialized digestive and reproductive systems adapted to its nectar-feeding diet and reproductive cycle. Here’s an overview of each system: 1. Digestive System of the Butterfly Butterflies primarily consume liquid food, such as nectar, using a specialized proboscis, which influences the structure of their digestive system. • Proboscis: A long, coiled tube-like structure…

The grasshopper (Orthoptera order) has well-adapted digestive and reproductive systems that support its herbivorous diet and high reproductive rate. Here’s an overview of both systems: 1. Digestive System of Grasshopper The grasshopper’s digestive system is suited to process fibrous plant material, which it primarily consumes. The system is broken down into distinct sections for food…

The field cricket (Gryllus spp.) has a digestive and reproductive system adapted to its omnivorous diet and reproductive strategy. Here’s a breakdown of both systems: 1. Digestive System of Gryllus The digestive system of a cricket is similar to other insects but adapted to digest plant material, insects, and organic matter. The main components are:…

The American cockroach (Periplaneta americana) has complex systems that support its survival, including a digestive and reproductive system well-suited to its scavenging and reproductive habits. Here’s an overview of both: 1. Digestive System The digestive system of the American cockroach is adapted to process a wide variety of foods, from organic waste to decaying materials….

Insects undergo a highly diverse and specialized development process that transforms them from eggs to adults. This process is closely linked to their ecological roles and life cycle strategies. Insects exhibit direct development or metamorphosis, the latter being either incomplete or complete. Types of Insect Development 1. Ametabolous Development (No Metamorphosis) • Definition: Insects hatch…

The reproductive system of insects is highly specialized and varies between species, but it generally functions to produce, store, and transfer gametes for successful reproduction. Insects reproduce sexually, although some species exhibit forms of asexual reproduction like parthenogenesis. Most insects are dioecious (separate sexes), but a few are hermaphroditic. General Structure of the Reproductive System…