Yellow poplar sawfly
| Yellow poplar sawfly | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
.jpg)
Yellow Poplar Cachet Wasp (♀) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Cimbex luteus | ||||||||||||
| ( Linnaeus , 1758) |
The Yellow Poplar cimbicidae ( Cimbex luteus ) is a plant Wasp (Symphyta) from the family of cimbicidae (Cimbicidae) and the genus Cimbex . The second part of the binomial - scientific name - the species name - refers to the appearance of the wasp (from Latin luteus = "golden yellow"). Like all four Cimbex species, the yellow poplar wasp is legally protected in accordance with Appendix 1 of the Federal Species Protection Ordinance in Germany . Furthermore, it is classified in the Red List of Endangered Animals, Plants and Fungi in Germany published by the Federal Agency for Nature Conservation in Category 2 and thus as "highly endangered".
description
Imago
The wasp reaches body lengths between 16 and 28 millimeters; most common are individuals around 25 millimeters in length. The wingspan can be up to 50 millimeters and the veined wings themselves are translucent as clear as glass with smoky brown, darker ends and edges. The legs are colored brown-red.
Like all species of the genus Cimbex , the yellow poplar sawfly has a noticeably semicircular cut out first abdomen segment with a membranous nakedness. The common characteristic and name-giving feature of the cudgel sawfly family are the four to seven-membered antennae, which are clearly thickened at the end to form a characteristic club. In Cimbex luteus , these clavate antennae have four segments. Another typical distinguishing feature of the family - also found in this case - is a broad abdomen , knurled on the sides, arched upwards and flat on the underside .
The dominant color scheme of the females is primarily yellow and secondarily brown. Cimbex luteus shows many similarities to the alder- clubhorn wasp ( Cimbex connatus ) and can be confused with it. The color is the decisive differentiating criterion, because Cimbex luteus - taking its German trivial name into account - has significantly more yellow body parts than Cimbex connatus , for example in much more extensive yellow areas on the abdomen. The thorax is usually light orange-brown in color and the back of the head and the scutellum are matted with dots and thicker hairs. There is a single black spot on the thorax behind the head. Often all segments of the abdomen are yellowish in color; the abdomen can sometimes be provided with dark purple bandages. In darker individuals, the first and second tergite can be completely brown, while the third tergite has at most a narrow brown central mark (in Cimbex Connatus, however , the third tergite is almost completely brown with only narrow yellow borders). In addition, the yellow poplar-clubhorn wasp has smaller, more blunt mandibles compared to the alder-clubhorn , which are also more clearly separated from each other.
In Cimbex luteus a striking occurs sexual dimorphism on. The male specimens have a slimmer figure than the female and, in contrast to these, are almost entirely very dark in color. Only the oval, first abdominal segment bears the light yellow color of the membranous nakedness.
larva
The adult larvae of the yellow poplar cachet wasp - so-called anal caterpillars - are comparatively thick and up to 40 millimeters long. They are also similar to those of Cimbex connatus , but show a more intense yellow color with advanced age. In addition, they only have one lateral row of black dots, whereas the larvae of Cimbex connatus have two. In addition, the dark dorsal stripe of the Cimbex luteus larvae has a bright blue central filling. The larvae have eight pairs of ventral feet , the first abdominal segment being legless. In addition to the six sternum bones of the thoracic segments, they have a total of 22 feet.
distribution
The main distribution area of the yellow poplar wasp is on the European continent . Here, however, it is absent on the island of Ireland , on all Mediterranean islands , on the Iberian Peninsula , in Norway , Iceland and northeastern Europe as well as in parts of the Balkan Peninsula . Outside of Europe, deposits in Siberia , Japan and the Korean Peninsula are documented. Despite the comparatively wide distribution, the sometimes very low population density and the hidden way of life of the adult animals ensure that they are often perceived as barely there, while the larvae are much easier and more frequent to observe.
Way of life
The females prefer to lay their eggs mainly willows , poplars and alders , rarely, birch . They saw - usually on the underside of the leaves or on the edge of the leaf - a pocket-shaped incision in the leaf blade , into which they lay the 50 to 80 cylindrical eggs. The cuts heal over the eggs, protecting them from predators and the weather. The larvae then feed freely on the leaves. In their resting position they sit curled up on the underside of the leaf. They are nocturnal and feed from the leaf edge as soon as it is dark. After about five to six weeks, they build a hard-shelled cocoon in the dry leaves on the ground or in the cracks of the bark of their host tree , in which they overwinter. They pupate in spring. The hatched adults finally fly between mid-April and July , but individually only live a few days. These adult animals are very good and, above all, fast fliers that feed on the sap of the trees mentioned. To do this, they score young twigs or shoots in order to get to the sap.
Both in terms of size and the color costume show the female of Cimbex luteus a hornets - mimicry . Nonetheless, the species faces a wide range of enemies. Apart from predators provide for Yellow Poplar cimbicidae especially egg, larval and cocoon parasites and representatives of chalcids family Eulophidae problems.
Cimbex luteus as a pest
The yellow poplar sawfly has been known as a forest pest on poplar and willow trees at least since the beginning of the 20th century . The greatest danger comes from the adult specimens, which curl young twigs or shoots when searching for food . Since the fine incisions - which, when they are fully encompassing, form a closed ring or a spiral - affect the periderm and are usually so superficial that the cambium is not removed, the activities of Cimbex luteus usually do not cause the death of the Growths. Thus, the feeding marks can completely back under normal circumstances überwallt be. This has the consequence that the shoots thicken strongly in the corresponding places and the wounds appear swollen.
A problem can arise because trees used as fodder crops by insects are fast growing species. As a result, there is a possibility that the wounds will be covered quickly, but not heal completely. This can lead to secondary fungal infections, which in the conspicuous thickening of the shoot axes result in wood rot . Areas attacked in this way represent mechanical weak points that can break even under low loads.
Compared to other forest pests, however, the influence of Cimbex luteus is subordinate. The feed often remains insignificant and often goes undetected, especially in older forest cultures . However, if countermeasures are necessary, insecticides as well as glue boards and glue strips are used.
research
After the first description by Carl von Linné , August Johann Rösel von Rosenhof and Pietro Rossi already dealt descriptively with the yellow poplar wasp and its larvae. The Swedish entomologist Carl De Geer also observed the metamorphosis from the anal caterpillar to the flightable insect over a period of 18 months . In 1816 Everard Home published a treatise in which he devoted himself, among other things, to the musculoskeletal system of Cimbex luteus .
In the Netherlands in particular , numerous biologists researched the harmful effects of the yellow poplar sawfly in the 1930s, as well as effective plant protection. For example, Cornelia Venema-Schaeffer gave lectures on this. LP de Bussy, Evelyn F. Jacobi, Pieter Adrianus van der Laan and Alexey Diakonoff examined the effects of the insecticide Rotenone . They came to the conclusion that the larvae of Cimbex luteus react "sensitively" ( nl .: Gevoelig ) to pollination with the dried powder of the roots of the tuba root ( Derris elliptica ) - this is the middle level of their five-stage scale. In Austria , the harmful effects of the yellow poplar- keulhorn wasp are examined primarily on energy wood plantations.
The majority of the other research, however, not treated Cimbex luteus exclusive, but the family of cimbicidae generally with only single mentions of Cimbex luteus .
Individual evidence
- ↑ Martin Gellermann, Matthias Schreiber: Protection of wild animals and plants in state planning and approval procedures. Practical Guide . In the series: "Nature and Law Series", Volume 7. Springer Science + Business Media , Heidelberg , 2007, ISBN 978-3-540-69096-2 , page 368.
- ↑ a b c d e f g Bernhard Perny, Manuel Völkl: Damage by Keulhorn sawfly on poplars on energy wood surfaces . In: Forstschutz Aktuell, № 48, December 2009, pages 15–17.
- ↑ Information about the yellow poplar sawfly on a private homepage about plant wasps in Great Britain and Ireland. Retrieved from sawflies.org.uk on March 14, 2020.
- ↑ Anton Benedict Reichenbach: Picture gallery of the animal world, or pictures of the most interesting from the animal kingdom with detailed description . Published by E. Pönicke & Sohn, Leipzig , 1835, page 20.
- ↑ Jiří Zahradník : The Cosmos Insect Guide. An identification book with 1000 colored illustrations . In the series: " Kosmos -Naturführer". 5th edition, Franckh'sche Verlagshandlung , Stuttgart , 1989, ISBN 3-440-05989-8 , page 212.
- ↑ Theodor Hartig : Die Aderflügler Germany with special consideration of their larval state and their work in forests and gardens for entomologists, forest and garden owners. First volume: The families of sawfly and wood wasps together with a general introduction to the natural history of the Hymenoptera . Haude and Spenersche Buchhandlung , Berlin , 1837, pages 66-67.
- ^ Everard Home : Further observations on the feet of animals whose progressive motion can be carried on against gravity . 1816.
- ↑ German Dendrological Society ( ed. ): Communications of the German Dendrological Society . Edition 52, Verlag L. Beissner, 1939, page 187.
- ↑ Nederlandse Dendrologische Vereniging ( ed. ): Jaarboek . Volume 13, H. Veenman & Zonen, Wageningen , 1938, page 17.
- ^ LP de Bussy, Pieter Adrianus van der Laan, Evelyn F. Jacobi: Results van proeven met Derrispoeder en Rotenon op Nederlandsche insecten . In: Tijdschrift over plantenziekten, 41st volume, 2nd edition, February 1935, pages 34–52.
- ^ LP de Bussy, Pieter Adrianus van der Laan, Alexey Diakonoff: Bestrijding van Nederlandsche insecten met Derris . In: Tijdschrift over plantenziekten, 42nd year, 4th edition, April 1936, pages 77-104.
- ↑ Erwin Führer, Hildegund Bacher: Biotic harmful risks in energy wood plants . In: Anzeiger fur pest science, plant protection, environmental protection, 64th year, issue 1, January 1991, pages 1-8.