Holoptic refers to one of the ways in which the

arthropod eye Eye#Apposition eyes, Apposition eyes are the most common form of eye, and are presumably the ancestral form of compound eye. They are found in all arthropod groups, although they may have evolved more than once within this phylum. Some annelid ...

develops, particularly the

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

of various species of insects. Unlike dichoptic and cycloptic eyes, holoptic eyes meet along the median dorsal line of the head, in many species nearly covering the exterior of the head. Holoptic eyes are typical of several

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

n males, in particular some Syrphidae, Tabanidae,

Pipunculidae Pipunculidae is a family of flies (Diptera) commonly termed big-headed flies, a reference to the large ( holoptic) eyes, which cover nearly the entire head. The family is found worldwide and more than 1300 species have been described. The larva ...

, and

Acroceridae The Acroceridae are a small family of odd-looking flies. They have a hump-backed appearance with a strikingly small head, generally with a long proboscis for accessing nectar. They are rare and not widely known. The most frequently applied common ...

. Some other insect orders that include species with holoptic males and some in which the females are holoptic as well, include the

Coleoptera Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

Anisoptera A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens ...

, and

Archaeognatha The Archaeognatha are an order of apterygotes, known by various common names such as jumping bristletails. Among extant insect taxa they are some of the most evolutionarily primitive; they appeared in the Middle Devonian period at about the sa ...

References

* {{Insect-anatomy-stub Insect anatomy Eye