حشریات
حشریات یا علم حشرات الارض انگریزی Entomology حیوانیات کی ایک شاخ ہے جو حشرات کی ساخت عادات اور درجہ بندی سے تعلق رکھتی ہے حیوانیات کی اس شاخ میں حشرات کا مطالعہ کیا جاتا ہے اس کو انگریزی میں Entomology کہا جاتا ہے Entomology سانچہEty is the scientific study of insects a branch of zoology In the past the term insect was less specific and historically the definition of entomology would also include the study of animals in other arthropod groups such as arachnids myriapods and crustaceans This wider meaning may still be encountered in informal use Like several of the other fields that are categorized within zoology entomology is a taxonbased category any form of scientific study in which there is a focus on insectrelated inquiries is by definition entomology Entomology therefore overlaps with a crosssection of topics as diverse as molecular genetics environmental archaeology behavior neuroscience biomechanics biochemistry systematics physiology developmental biology ecology morphology and paleontology Over  million insect species have been described more than twothirds of all known species Some insect species date back to around  million years ago They have many kinds of interactions with humans and other forms of life on Earth For example species such as P pyralis conduct bioluminescent reactions in their lightemitting organs which have been the subject of much research especially in recent years