Zusammenfassungen der Arbeitskreisbeiträge - Die DPG

habitat preferences. Parentage and kinship analysis of the offspring to analyze individual
foraging decisions is in progress.
THE CHALCID WASP SCHIZONOTUS SIEBOLDI (PTEROMALIDAE) AS A PUPAL
PARASITOID OF THE RED POPLAR LEAF BEETLE, CHRYSOMELA POPULI L.
(COLEOPTERA: CHRYSOMELIDAE), IN SHORT ROTATION COPPICE (SRC)
Richard Georgi, Michael Müller
Technische Universität Dresden, Professur für Forstschutz, Pienner Str. 8, 01737 Tharandt
Email: richard.georgi@tu-dresden.de
Chrysomela populi is the main pest species in SRC (short rotation coppice) with poplar in
Germany. Mass development of this pest species can result in loss of increment and loss of
cuttings and coppice shoots. The larger the area of SRC and the greater their linking the
higher is the probability for damage. Therefore, this species has become more and more an
important economic factor when managing SRC. There is relatively little knowledge about
natural enemies of C. populi. The chalid wasp Schizonotus sieboldi has been proven to be a
very important pupal parasitoid on all three investigated study sites in Brandenburg and
Saxony. The parasitation rate ranged from 35% to 73% (50% on average) in a total of six
investigations. Imagines of S. sieboldi deposit eggs on the abdominal side of the pupae thorax.
The development of the six larval stages and the pupal stage takes place under the wing pads
and the thoracic appendages of C. populi. In average11.5 adults of S. sieboldi (maximum 29)
emerged per pupae. The more pteromalid wasps emerged per pupae the higher is the male
percentage. Female Imagines are significantly larger (2.61 mm on average) than male
Imagines (2.19 mm on average). With respect to the introduction of guidelines for Integrated
Pest Management (IPM) in 2014, this natural enemy is a potential species to prevent mass
outbreaks of C. populi. Further research is needed in terms of promoting S. sieboldi by
improving of habitat structures.
PARASITOIDS OF THE MULBERRY SCALE PSEUDAULACASPIS PENTAGONA
H. Rauleder, R. Albert
Agricultural Technology Centre Augustenberg (LTZ), Stuttgart
Email: reinhard.albert@ltz.bwl.de
The mulberry scale originates from East Asia and was imported to Italy at the end of the
nineteenth century. The first detection in Germany was in the 60s in Bavaria. The scale has
been active in Baden-Wuerttemberg since 1985. Since about 10 years heavy infestation by the
scale insect with massive damage has occurred in commercial horticulture and since about 5
years also in private gardens. The foliage of infested trees often becomes sparse and yellow.
Heavy infestations can lead to stunted growth, premature fruit drop and may result in the
death of the host plant.The trunk, branches and twigs of heavily infested plants may look as if
whitewashed. From the United States of America 121 host plants are known. These include
among others peaches, currants, raspberries, maple, bluebeard, pear, blue bells, oak, ash, lilac,
kiwi, lime, mulberry, black locust, catalpa and walnut. The mulberry scale has 2 generations
per year in the north and four generations in the south. The adult female is a yellowish-white
to reddish-orange unsegmented (sac-like) insect about 1 mm in diameter. The females are
covered by an oval to circular scale, which is normally white with a brown centre and 2 - 2.5
mm in diameter. The adult male is a tiny aphid-like yellow insect, less than 1 mm long, with
only two-wings (wing span is 1.4 mm) but four eyes and a long genital stylus at the end. The
scale of immature males is snowy white and 1.5 mm long. The 100-150 eggs are laid by the
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