Search results
Results from the WOW.Com Content Network
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. The field is also referred to as insectology in American English, while in British English insectology implies the study of the ...
Here, the vertex, or the apex (dorsal region), is situated between the compound eyes of insects with hypognathous and opisthognathous heads. In prognathous insects, the vertex is not found between the compound eyes, but rather where the ocelli are normally found. This is because the primary axis of the head is rotated 90° to become parallel to ...
Paired, mobile, and segmented, they are located between the eyes on the forehead. Embryologically, they represent the appendages of the second head segment. [8] All insects have antennae, however they may be greatly reduced in the larval forms. Amongst the non-insect classes of the Hexapoda, both Collembola and Diplura have antenna, but Protura ...
Insects that feed on or parasitise other insects are beneficial to humans if they thereby reduce damage to agriculture and human structures. For example, aphids feed on crops, causing economic loss, but ladybugs feed on aphids, and can be used to control them. Insects account for the vast majority of insect consumption. [173] [174] [175]
Arthropod hemolymph contains high levels of free amino acids. Most amino acids are present but their relative concentrations vary from species to species. Concentrations of amino acids also vary according to the arthropod stage of development. An example of this is the silkworm and its need for glycine in the production of silk. [8]
An instar (/ ˈ ɪ n s t ɑːr / ⓘ, from the Latin īnstar 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (ecdysis) until sexual maturity is reached. [1] Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in ...
Insects are the only group of invertebrates that have evolved wings and flight. Insects first flew in the Carboniferous, some 300 to 350 million years ago, making them the first animals to evolve flight. Wings may have evolved from appendages on the sides of existing limbs, which already had nerves, joints, and muscles used for other purposes.
These minute arthropods are apterous, unlike some orders of insects that have lost their wings secondarily (but are derived from winged ancestors). Their mouthparts are enclosed within a pouch in the head capsule, called the gnathal pouch, so only the tips of the mandibles and maxillae are exposed beyond the cavity. [1]