Stenogastrinae
| Stenogastrinae | ||||||||||||
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Liostenogaster vechti |
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| Scientific name | ||||||||||||
| Stenogastrinae | ||||||||||||
| Bequaert , 1918 |
The Stenogastrinae are a subfamily of the folded wasps (Vespidae). The approximately 70 described species in seven genera live in tropical East Asia.
features
Stenogastrinae are relatively small Vespidae, they reach a body length of about 1 to about 2 centimeters. In the terrain, they stand out due to their characteristic soaring flight (therefore called hover wasps ). They are dark brown to black in color, with yellow markings of varying dimensions, with males and females in most species being difficult to distinguish. The stenogastrinae are slender with relatively short legs and a slender and remarkably long petiolus . The representatives of the subfamily differ from other Vespids in the combination of the following features: The wing scales ( tegulae ) are widely separated from the pronotal lobe (a lobe-shaped process at the rear edge of the pronotum ) (always wider than the diameter of the lobe). At the head the clypeus is usually pointed in front, sometimes rounded. Because of this, and because of the long mandibles , the head appears triangular when viewed from the front. Resting animals are also noticeable because the forewings are not folded lengthways, as is typical for the wasps.
Biology and way of life
As far as known, all species of the Stenogastrinae are social insects with eusocial social behavior ; that means joint procurement of food, cooperative brood care and coexistence of animals of several generations. As is typical for relatives, they build nests from a paper-like substance made from chewed wood fibers, but alternatively also other chewed plant fibers or clay. The colonies of the Stenogastrinae remain relatively small, even with the most populous species of the genus Liostenogaster they consist of fewer than 40 individuals in nests with a maximum of about 100 brood cells.
Unique to the genus is a milky-white, gelatinous substance that is secreted by the Dufour's glands (on the abdomen) and that serves various purposes. With their help, the egg is cemented into the brood cell. Later, the larvae use them as an anchor and a place to stay, on which the adults then deposit solid and liquid food for the larvae. To do this, either a drop of protein-rich liquid is choked out or chewed insect prey is delivered. This food can then be distributed to other larvae, it forms a food supply for the colony. In addition, the sticky secretion of Dufour's glands is deposited on the edge of the nest to keep ants away.
The development time from egg laying through the various larval stages to the hatching of the adults from the pupal shell is 44 to approx. 100 days for the examined species. The colonies usually start producing sex animals at an early stage, and the first male is often hatched in nests with only five cells. It is not uncommon for a young female to later replace the nest-building queen, so that individual colonies may persist for a long time. In the Stenogastrinae there is no sharp distinction between workers and queens. Females usually start out as workers, but older females then develop ovaries and can begin to lay eggs. Females older than about 20 to 50 days usually always reach sexual maturity and are mated by males. They can then remain in their mother colony for a long time, which often includes numerous egg-laying females. Dominance hierarchies have been demonstrated in some species, in which dominant females prevent the subordinate from laying eggs, so that these remain functional workers or at least lay fewer eggs than they do. The behavior of the females is, depending on the environmental conditions, extremely plastic: they can remain in the birth colony, join a foreign colony (or try to take it over by killing the queen) or fly out and try to found their own colony, as observed in the well-studied Listenogaster flavolineata . Often only a few (one or two) females are active outside the nest at the same time, providing food for the entire colony.
Nests of the stenogastrinae are usually established independently by a single female (haplometrosis). In some species pleometrosis has been observed in which two females start building nests together.
Nests
Stenogastrinae prefer to nest in dark, humid places with constantly high humidity, mostly in sheltered places such as overhanging cliffs or banks, and man-made structures such as bridges or water pipes. However, some species also nest in more exposed places such as branches of trees. Often there are numerous nests in favorable locations, colony-like in close proximity to one another.
The nests in the Stenogastrinae species are variable in shape. They are always attached directly to the nest substrate and never have a stalk (as in the Polistinae). Old nests are often reused, partly rebuilt, when building new ones. They usually consist of cells placed side by side on a flat surface or a linear element such as a stalk or liana. Some species build clay nests, others use wood or plant fibers, as is typical for the relationship. There are all shapes, from randomly or linearly assembled cells to ring-shaped honeycombs to flat honeycomb plates. At Eustenogaster , the pear-shaped nests are surrounded by a closed shell. At Metischnogaster , a bell-shaped open shell is created that protects the brood cells from rain.
distribution
Stenogastrinae live exclusively in tropical East Asia, in rainforests from southern India and Sri Lanka in the west to New Guinea in the east.
Phylogeny and Systematics
There is still no agreement on the position of the stenogastrinae in the system. Morphological features suggest a common kin group of Stenogastrinae, Polistinae and Vespinae , which would make it probable that the eusocial way of life within the Vespidae would have developed only once. However, genetic data contradict this position; accordingly the eusocial way of life would have arisen convergently twice . A current analysis revealed a basal position within the Vespidae, with all other subfamilies together as a sister group
The subfamily includes the following genera:
- Anischnogaster Van der Vecht , 1972. Endemics of New Guinea.
- Cochlischnogaster Dong and Otsuka, 1997. ( syn. Chalogaster Carpenter and Starr, 2000). China, Thailand, Vietnam.
- Eustenogaster Van der Vecht, 1969
- Liostenogaster Van der Vecht, 1969
- Metischnogaster Van der Vecht, 1977
- Parischnogaster von Schulthess , 1914 ( syn.Holischnogaster Van der Vecht, 1977)
- Stenogaster Guérin-Méneville , 1831. Endemics of New Guinea.
It is hardly possible to state numbers of species because numerous undescribed species are known and new species are regularly described.
swell
- Stefano Turillazzi: The Stenogastrinae. Chapter 3 in Kenneth G. Ross, Robert W. Matthews: The Social Biology of Wasps. Cornell University Press (Comstock Publishing) Ithaca and London, 1991. ISBN 0-8014-2035-0 .
- Stefano Turillazzi (1989): The Origin and Evolution of Social Life in the Stenogastrinae (Hymenoptera, Vespidae). Journal of Insect Behavior 2 (5): 649-661.
Individual evidence
- ↑ a b James M. Carpenter & Lien Phuong Thi Nguyen (2003): Keys to the genera of social wasps of South-East Asia (Hymenoptera: Vespidae). Entomological Science 6: 183-192.
- ^ Henri Goulet & John T. Huber (editors): Hymenoptera of the world: an identification guide to families. Center for Land and Biological Resources Research, Ottawa, Ontario, Research Branch Agriculture Canada Publication 1894 / E. ISBN 0-660-14933-8 . on page 214.
- ↑ Jeremy Field: The Ecology and Evolution of Helping in Hover Wasps (Hymenoptera: Stenogastrinae). Chapter 4 in Judith Korb, Juergen Heinze (editors): Ecology of Social Evolution. Springer Verlag, Berlin and Heidelberg 2008. ISBN 978-3-540-75956-0 .
- ↑ Heather M. Hines, James H. Hunt, Timothy K. O'Connor, Joseph J. Gillespie, Sydney A. Cameron (2007): Multigene phylogeny reveals eusociality evolved twice in vespid wasps. Proceedings of the Nationall Academy of Sciences USA 104 (9): 3295-3299. doi: 10.1073 / pnas.0610140104
- ↑ Patrick K. Piekarski, James M. Carpenter, Alan R. Lemmon, Emily Moriarty Lemmon, Barbara J. Sharanowski (2018): Phylogenomic Evidence Overturns Current Conceptions of Social Evolution in Wasps (Vespidae). Molecular Biology and Evolution 35 (9): 2097-2109. doi: 10.1093 / molbev / msy124 (open access).
- ↑ James M. Carpenter & Jun-ichi Kojima (1996): Checklist of the Species in the Subfamily Stenogastrinae (Hymenoptera: Vespidae). Journal of the New York Entomological Society 104 (1/2): 21-36.
- ↑ James M. Carpenter (2001): New generic synonymy in Stenogastrinae (Insecta: Hymenoptera; Vespidae). Natural History Bulletin of Ibaraki University 5: 27-30.