Pergidae
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Female of Lophyrotoma zonalis on leaf of Melaleuca sp. before oviposition |
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| Pergidae | ||||||||||
| Rohwer , 1911 |
The Pergidae are a family of plant wasps . The diverse family is divided into 14 subfamilies and includes around 440 species. Pergidae live in South America and Australia, a genus also in North America.
features
The Pergidae are morphologically very diverse. While most of the other plant wasp families can be well characterized by the structure of the antennae, in the Pergidae these are partly thread-shaped, partly with a large, clawed end member, partly with tooth-shaped extended ("combed") or lamellar extended ("sawn") flagellum limbs can comprise between four and 29 segments. Members of the family are best recognizable by the characteristic reductions in the wing veins. The radial cell in the fore wing is always undivided (without a transverse artery), anal cells are absent, or there is rarely a very small one. In the hind wing there are neither medial nor anal cells. Only in this family there are some wingless or short-winged (brachyptere) species among the plant wasps.
Larvae
The larvae of most species live freely on plants and have the typical anal caterpillar shape of the sawfly larvae with a sclerotized, round head capsule with a single-lens larval eye, an elongated, caterpillar-shaped shape with three pairs of thoracic legs and a different number of pairs of pseudopods on the abdomen . Few species minieren in stems ( Enjijus ) or leaves ( Corynophilus , Phylacteophaga ) and have the characteristic of this way of life regressions on. The larvae living in the wild are often yellow or green in color, but often have conspicuous warning colors. They are usually somewhat flattened with a broad ventral side and often have lobe-shaped growths on the sides of the body, sometimes also thread-like dorsal appendages. Some species are noticeably hairy, which is unusual for plant wasps. The larvae of the Australian subfamily Perginae, which feed on eucalyptus and other myrtle plants, have characteristic redesigned mouthparts. On the inside of the mandibles, they have a lobe-shaped or brush-shaped outgrowth with which they can separate the poisonous oils, which contain many secondary plant substances, from the nutritious leaf substance when they eat. Many leaf-dwelling larvae raise their abdomen when threatened, resulting in a characteristic U-shaped frightened position. In this position, poisonous or deterrent substances are presented to drive away predators. The larvae of most species contain toxins, either phytochemicals taken up by the forage plant or self-synthesized peptides.
Way of life
Most species feed on the leaves of a variety of different plant species. Among the Australian species, a particularly large number of species specialize in trees of the endemic genus Eucalyptus . The North American Acordulecera species feed on the leaves of various deciduous trees. For most tropical species, especially from South America, the nutrient plant and way of life is unknown. What is unusual among the plant wasps is that some species specialize in dead leaf litter on the forest floor or in mushrooms. In the leaf-dwelling species, the female lays the eggs with her ovipositor usually in rows under the epidermis near the midrib, more rarely also on the leaf margin, the forage plant. In some species, the females guard the clutch against parasitoids . The hatching larvae eat individually or in larger groups, depending on the species. The adult larvae pupate as a rule in a web in the ground or within the leaf litter. Some larvae that eat eucalyptus pull down from the trees in large armies at the same time on the trunk to the ground.
Economic importance
A number of species are considered to be pests, primarily due to forest tree defoliation. A number of species harm different Eucalyptus species. The Chilean species Cerospastus volupis causes baldness on southern beeches ( Nothofagus ). Another problem in South America is cattle poisoning from accidentally eaten, poisonous larvae.
Some species are tested for use in biological pest control, mostly against introduced plant species. In Florida, the species Lophyrotoma zonalis is being considered against the threateningly spreading myrtle heather, which was introduced as an ornamental plant . Use has not yet been approved because of concerns about the toxicity of the larvae.
distribution
The species of the family live almost exclusively in Australia and South America, from tropical to cool temperate latitudes. Such a distribution picture is mostly associated with an emergence on the former southern continent Gondwana , when the family split up into today's continents. In contrast to some other families with similar distribution, the Pergidae are absent in South Africa. The family has spread to North America, north to Canada, with a single genus, Acordulecera , which is also the only genus on the Caribbean islands. In the Australasian region they come from Australia and Tasmania in New Guinea, with two species even as far as Indonesia. They are absent in New Zealand and New Caledonia (now an introduced species).
Systematics
The Pergidae belong to the superfamily of sawfly-like. Their sister group is very likely the family of the brush horn sawfly (Argidae). The diverse family includes fourteen subfamilies living in either Australasia or America.
swell
Individual evidence
- ^ S. Schmidt, AE McKinnon, CJ Moore, GH Walter: Chemical detoxification vs mechanical removal of host plant toxins in Eucalyptus feeding sawfly larvae (Hymenoptera: Pergidae). Journal of Insect Physiology, 56, 12, pp. 1770-1776, 2010 doi : 10.1016 / j.jinsphys.2010.07.006
- ^ Roberto Carillo & Luis Cerda: Zoofitofagos en Nothofagus Chilenos. Bosque 8, 2, pp. 99-103, 1987
- ^ Roy Van Driesche, Bernd Blossey, Mark Hoddle, Suzanne Lyon, Richard Reardon: Biological Control of Invasive Plants in the Eastern United States. Forest Health Technology Enterprise Team (Morgantown, West Virginia). USDA Forest Service Publication FHTET-2002-04, 2002
literature
- Stefan Schmidt, S. & David R. Smith: An annotated systematic world catalog of the Pergidae (Hymenoptera). Contributions of the American Entomological Institute, 34, 3, pp. 1-207, 2006
Web links
- Stefan Schmidt: Pergidae of the World . Zoological State Collection Munich