|
Invertebrate Photoreceptor
A simple eye (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-lensed "compound eye", and is not necessarily at all simple in the usual sense of the word. The structure of an animal's eye is determined by the environment in which it lives, and the behavioural tasks it must fulfill to survive. Arthropods differ widely in the habitats in which they live, as well as their visual requirements for finding food or conspecifics, and avoiding predators. Consequently, arthropod eye, an enormous variety of eye types are found in arthropods. They possess a wide variety of novel solutions to overcome visual problems or limitations. Use of the term ''simple eye'' is flexible, and must be interpreted in proper context; for example, the Human eye, eyes of humans and of other large animals such as most Cephalopod, cep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polistes Ocelli
Wasps of the cosmopolitan genus ''Polistes'' (the only genus in the tribe Polistini) are the most familiar of the polistine wasps, and are the most common type of paper wasp in North America. Walter Ebeling coined the vernacular name "umbrella wasps" for this genus in 1975 to distinguish it from other types of paper wasp, in reference to the form of their nests. It is also the single largest genus within the family Vespidae, with over 300 recognized species and subspecies. Their innate preferences for nest-building sites leads them to commonly build nests on human habitation, where they can be very unwelcome; although generally not aggressive, they can be provoked into defending their nests. All species are predatory, and they may consume large numbers of caterpillars, in which respect they are generally considered beneficial. The European paper wasp, ''Polistes dominula'', was introduced into the US about 1981 and has quickly spread throughout most of the country, in most cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
