Ommatidae
Ommatidae | ||||||||||||
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![]() Omma stanleyi |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Ommatidae | ||||||||||||
Sharp & Muir , 1912 |
The Ommatidae are a species-poor family of beetles within the most primitive suborder of the beetles, the Archostemata . The family occurs worldwide with six species in two subfamilies and genera.
features
Beetle
The types of the two subgroups differ significantly from each other. Those of the genus Omma are 6 to 27 millimeters long and 2 to 9 millimeters wide, those of the genus Tetraphalerus reach a length of 10 to 16 millimeters, with a width of 2 to 3.5 millimeters. In the first genus, the flattened body is rounded at the side and has a brown to dark brown, almost black color. The body is covered with scales and scale-like hairs, which in some species form white patterns on the head, thorax and the wings . The entire surface of the body is covered with fine tubercles measuring 30 to 100 micrometers in diameter. The mouthparts are directed forward, the head is slightly longer than it is wide. There are no indentations for the antennae , the compound eyes on the sides are medium-sized. The head suddenly tapers behind the eyes, giving it a neck. The antennae are on the side of the head, in front of the eyes. They are eleven-limbed, thread-like and either the same length or shorter than the head and thorax combined. Only in O. rutherfordi do they extend beyond the base of the pronotum. The thorax has no indentations for the legs. All corners of the pronotum are rounded, the widest point is in the front half. The upper wings carry 9 to 10 rows of longitudinal veins typical of the suborder Archostemata, which are connected to one another by transverse veins so that there are windows in the spaces between them. The hind wings (alae) are usually well developed, only in O. rutherfordi they are very short and have no wing veins . The abdomen has five contiguous ventrites .
The adults of the genus Tetraphalerus have slender, flattened bodies with parallel side edges. They are gray in color, sometimes with rows of brown dots on the wings. The microtubercles have a characteristic mushroom or umbrella shape with short, strong hairs. The mouthparts are directed forward, the head is 1.5 to 1.7 times longer than it is wide. Grooves for the antennae extend from the base of the antennae below the eyes to the beginning of the neck. The eyes are on the sides about in the middle of the head. The thread-like feelers are also eleven-parted. In T. bruchi they are as long as the head, in T. wagneri they are as long as the head and thorax combined. The pronotum is widest in the middle, the front edge is narrower than the back. All corners of the pronotum are rounded.
Larvae
The only known larva believed to belong to the genus Omma was found in Western Australia. It was 12 millimeters long and had an elongated and slightly flattened body. The head has four well-developed point eyes ( ocelli ) on each side . With the exception of the mouthparts, it is weakly pigmented, behind the head the body is pale yellowish pigmented. The mouthparts are directed forward. The antennae are four-part. The six-limbed legs, including the well-developed pretarsal claws, are short and far apart.
Occurrence
The family consists of two genera, the distribution of which is disjoint . The species of the genus Omma are distributed in the east, southeast and southwest of Australia, whereas the genus Tetraphalerus occurs in the southern half of South America. The species of the genus Omma inhabit both densely forested coastal areas and dry eucalyptus forests west of the Great Dividing Range . The species of the genus Tetraphalerus live in open, dry bushland.
Way of life
Larvae of the genus Omma were found on dead wood and tree roots. Omma mastersii and Omma sagitta see a Ameisenwespenart and a Thanasimus species similarly, is therefore believed that these types a Mimikryring ( Mullerian mimicry form). Due to their habitat, the Tetraphalerus larvae are believed to develop in the roots or trunks of bushes. The adults appear to be nocturnal, which suggests frequent catches in light traps.
Taxonomy and systematics
The Ommatidae are separated from the other beetle families by the vertical cutting edges of the mandibles and by the deep indentations of the dorsal sensory hairs of the apical palpomeres . The following types are known so far:
Subfamily Ommatinae
Subfamily Tetraphalerinae
supporting documents
Individual evidence
- ↑ a b c d e f Rolf G. Beutel, Richard AB Leschen: Handbuch der Zoologie - Coleoptera, Beetles, Volume 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) . 1st edition. de Gruyter , 2005, ISBN 3-11-017130-9 , p. 38 ff . (English).
literature
- Rolf G. Beutel, Richard AB Leschen: Handbuch der Zoologie - Coleoptera, Beetles, Volume 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) . 1st edition. de Gruyter , 2005, ISBN 3-11-017130-9 (English).