Zum Auftreten der Robinien-Miniermotte,Phyllonorycter robiniella (Clem.) und der Roßkastanien-Miniermotte,Cameraria ohridella Desch. & Dim. (Lep., Gracillariidae) in Südtirol

The examples of two species of Gracillariidae,Phyllonorycter robiniella andCameraria ohridella, show how fast the expansion can take place: The robinia-leafminerP. robiniella was first noticed in South Tyrol in 1991 and an outbreak occured on False Acacias near Brixen, already in 1996.—The horsechestnut leafminerC. ohridella was first noticed in the Pusteria Valley near Toblach-Dobiacco, in 1992 (Butin &; Führer, 1994). The latest research, of autumn 1997, shows that they are now distributed on Horse Chestnut Trees (Aesculus hippocastanum) in the whole Isarco Valley, between Fortezza and Bozen-Bolzano (Tab. 1), whereas in the Adige Valley at south and west of Bolzano no occurrence could be found as yet.     

Integrated control of the solitary carpenter worm,Paropta paradoxa H.-Schaeff. (Lep., Cossidae) on fig trees in Egypt

According to the new trend of insect pests control in fruit orchards, biological in addition to mechanical control were evaluated for their efficiency on the reduction ofP. paradoxa population on fig trees during 1996, 1997 and 1998. Primary trials using the bacterial biopreparations of Delfin, Dipel and Bactospeine at the concentration of 200g/100 l. w. resulted in 81.8, 75.8 and 72.3% reduction of pest infestation, respectively. Pruning the infested branches, worming the larvae inside their tunnels and both mechanical treatments together along two successive years, reduced the infestation by 17.5, 47.4 and 57.9%, respectively. A control programme ofP. paradoxa was conducted using the techniques of pruning and worming besides spraying with bacterial insecticides at a rate of 200g/100 l.w. The performed mechanical and biological treatments together for one year gave 79.2–94.5% reduction of infestation, that reduction increased to 83.0–98.1% when these treatments were applied two years successively.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.     

Studies on developmental stages of the horse chestnut scale insect,Pulvinaria regalis Canard (Hom., Coccidae), in the open land and in the laboratory

In the presented paper the development of horse chestnut scale insect,Pulvinaria regalis Canard, was studied a on red horse chestnut (Aesculus x carnea) in the urban area of Bonn. Secondly, the scale insect growth was determined on sycamore maple (Acer pseudoplatanus) and horse chestnut (Aesculus hippocastanum) at different temperatures in the laboratory.The field population displayed an insignificant linear increase in body length between July and beginning of December. No growth was observed between December and March but between mid of March and beginning of May the body size increased exponentially. By setting up a frequency distribution of the anal plate length and by simultaneous measurement of new and old anal plate during molting it was possible to separate different developmental stages. The length of the anal plates of first instar crawlers/settlers ranged between 0.030 and 0.054 mm, that of the second and third instar nymphs between 0.066 and 0.090 mm and 0.102 to 0.150 mm, respectively. The anal plate length of fourth instar adult females differed between 0.162 and 0.246 mm, whereas those of male puparians ranged between 0.075 and 0.098 mm. Since the cuticula ofP. regalis is very extensible, the separation of different developmental stages was only reliable by using the measure of the strongly sclerosed anal plate. Until 12. August first instar crawlers/settlers and till 29. September second instar nymphs were observed on red horse chestnut in the field. Female third instar nymphs were noticed between 9. September and 28. April and fourth instar adult females from 31. March on.In the laboratoryP. regalis individuals on horse chestnut and sycamore maple did only growth at 18°C and fluctuating temperature of 20/14°C (16/8 h). The growth was heavily affected at warm temperatures of 26°C and scale insects lived only a few weeks. Only at the fluctuating temperature of 20/14°C (16/8 h) some females laid eggs on horse chestnut and sycamore maple from the 49. and 48. week on.

---

Untersuchungen über Entwicklungsstadien der Wolligen NapfschildlausPulvinaria regalis Canard (Hom., Coccidae) im Freiland und Labor

Zusammenfassung In der vorliegenden Arbeit wurden die Entwicklungsstadien der Wolligen NapfschildlausPulvinaria regalis Canard im Freiland an einer Rotblütigen Roßkastanie (Aesculus x carnea) im Stadtgebiet von Bonn, sowie das Körperwachstum an Bergahorn (Acer pseudoplatanus) und Roßkastanie (Aesculus hippocastanum) bei unterschiedlichen Temperatubedingungen im Labor untersucht.Die Freilandpopulation zeigte von Juli bis Anfang Dezember eine geringe lineare, von Mitte Dezember bis Anfang März nahezu keine und von Mitte März bis Anfang Mai eine exponentielle Zunahme der durchschnittlichen Körperlänge. Durch das Aufstellen einer Häufigkeitsverteilung der Analplattenlänge sowie durch das gleichzeitige Messen von neuen und noch nicht abgestreiften alten Analplatten während der Häutungsphase konnte ein Maß zur Abgrenzung der Entwicklungsstadien ermittelt werden. Die Analplattenlänge von Crawlern/Settlern (=erstes Larvenstadium) lagen im Bereich von 0,030–0,054 mm, des ersten und zweiten Nymphenstadiums im Bereich von 0,066–0,900 mm und 0,102–0,150 mm. Bei adulten Weibchen lag die Analplattenlänge zwischen 0,162 und 0,246 mm und bei männlichen Präpuppen zwischen 0,075 und 0,098 mm. Da die Cuticula vonP. regalis sehr dehnbar ist, war eine sichere Stadienzuordnung nur mit Hilfe der stark sklerotisierten Analplatte möglich. Bis zum 12. August waren Crawler/Settler und bis zum 29. September Erstnymphen zu beobachten. Weibliche Zweitnymphen traten vom 9. September bis 28. April und adulte Weibchen ab dem 31. März in Erscheinung.Im Labor konnte auf den Versuchspflanzen Roßkastanie und Bergahorn ein Wachstum der Körperlänge vonP. regalis-Individuen bei Konstanttemperatur von 18°C und bei Wechseltemperatur von 20/14°C (16/8 h) gemessen werden. Bei einer Konstanttemperatur von 26°C war das Wachstum auf beiden Wirtspflanzenarten gestört und ein Überleben nur für wenige Wochen möglich. Nur in der Temperaturvariante 20/14°C (16/8 h) legten einige Weibchen ab der 49. Woche auf Roßkastanie und ab der 48. Woche auf Bergahorn Eier ab.

---

---

With 2 tables and 4 figures

---

Dedicated to Prof. Dr.W. Schwenke for 75th birthday 22.3.1996.     

Die pfirsichschildlausParthenolecanium persicae (F.) in Südbaden—ein für Deutschland neuer schädling der WeinrebeVitis vinifera L.

In 1998, a survey of scale insects infesting grapevine (Vitis vinifera) in southwestern Germany yielded four species, namelyHeliococcus bohemicus, Parthenolecanium corni, P. persicae andPulvinaria vitis. P. persicae is recorded for the first time in Germany. The last surveys on scale insects in southwestern Germany were conducted byWünn (1925, 1926) but at this timeP. persicae was not discovered yet in this region. Most probably the thermophilus species immigrated from Swizerland and spread northwards into the Rhine valley during the last two or three decades of years.P. persicae is attacked by four species of parasitoids and a hyperparasitoid. The most common species is the encyrtidBlastotbrix bungarica.     

Aktueller Stand des Vorkommens der Australischen Schabe (Periplaneta australasiae Fab.) in Deutschland

Among the five synanthropic cockroach varieties occuring in Germany, the Australian cockroach (Periplaneta australasiae) is the most infrequent species, it does represent a rarity. Its current distribution in Germany was investigated in 1996/97. Zoological and botanic gardens, with their hothouses offering optimal living conditions for this roach variety, were found to be focal sites of infestation. Similarly, a swimming bath facility and a museum were noted to be infested withP. australasiae for a lengthy period. In addition, few isolated sites of incidence were noted. The present work is a first time ever attempt to gain an overview of the incidence of Australian cockroach in Germany. The Australian cockroach is of no relevance as a public health pest in Germany.     

Dynamics of resistance to organophosphate and carbamate insecticides in the cotton whitefly <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Hemiptera: Aleyrodidae) from Pakistan

Field populations of adult whiteflies, Bemisia tabaci, from Pakistan were monitored from 1992 to 2007 for their susceptibility to seven organophosphate and three carbamate insecticides using a leaf-dip method. Malathion, quinalphos and chlorpyrifos generally exhibited no or a very low level of resistance in B. tabaci over a 16-year monitoring period. Resistance to profenofos, triazophos, parathion-methyl and ethion was usually low to high up to 1995, and then it dropped to very low levels during 1996–2004. Resistance levels again picked up from low to moderate levels for triazophos during 2005–2007, for parathion-methyl during 2003–2007, and for ethion in 2006. Among carbamates, thiodicarb resistance was high during 1994–1996, which dropped to moderate levels in 1997 and 1998 and to very low levels during 1999–2001, but again increased from low to high levels during 2002–2007. Methomyl resistance was moderate in 1994 and 1995, which dropped to very low levels during 1996–2002, and then increased to low levels during 2003–2007. Butocarboxim resistance remained very low during 1994–2003 and then increased from low to high levels during 2004–2007. The insecticides exhibiting no, very low or low resistance, and no cross-resistance among themselves can be exploited in devising an insecticide resistance management strategy to combat whitefly resistance in the field.     

Application of some bacterial varieties ofBacillus thuringiensis and its bioproduct Delfin onSynanthedon myopaeformis Borkh. (Lep. Aegeriidae) in apple orchards

Field experiments were conducted using the biological agentBacillus thuringiensis to control the clearwing moth,Synanthedon myopaeformis (Lep. Aegeriidae) in apple orchards at Alexandria governorate during 1995, 1996 and 1997. Three bacterial varieties ofB. thuringiensis showed significant influence on the reduction of borer infestation. Four applications with the sporic concentration 12×10⁷ spores/ml of each ofB. th. var.kurstaki, B. th. var.alesti andB. th. var.thuringiensis induced 82.5, 51.1 and 42.1% reduction of infestation, respectively. Methods of application showed highly significant effect on infestation level. Sparying after scraping was the best method (80.0%, reduction) followed by painting after scraping (71.5%, reduction) then spraying alone (59.7%, reduction) or painting alone (43.0%, reduction). A control programme was carried out using three applications of the biomaterial, Delfin at the rate of 200 g/100 I.w. during mid-March, early June and mid-August resulted in 88.5–91.4% reduction of infestation.     

Rindenkrebs der Eßkastanie (Cryphonectria parasitica) in Südwestdeutschland

Chestnut blight (Cryphonectria parasitica) in South-west Germany . In 1992 and 1993, chestnut blight (Cryphonectria parasitica) was found in three stands in the south-west of Germany. Each of the three stands has only one compatibility group (vc-group). Two of them (97 and 75 Isolates) belong to the vc-group I. They are compatible with the Swiss vc-group I. The 43 Isolates from the third stand were not compatible with the most common Swiss vc-groups (vc-group I-V). In the German vc-group I, one hypovirulent strain was found.     

The effect of Sirex noctilio infestation and fire damage on the chemical composition of South African-grown Pinus patula pulpwood

The infection and association between the wood wasp Sirex noctilio and the fungus Amylostereum areolatum is responsible for large-scale tree mortality in the Midlands of the KwaZulu-Natal province in South Africa. An exploratory investigation on the effect of the infestation of trees by the wood wasp and its associated fungus on the chemical composition of Pinus patula pulpwood was undertaken. Various tree classes representing different levels of physiological growth stress from this infestation were compared. Together with the above stress agents, fire damage to P. patula trees was also considered as a possible cause of changes in pulpwood chemical composition. Chemical analyses to determine the Seifert cellulose and Klason lignin contents as well as the levels of water- and solvent-soluble extractives were conducted using published Tappi standard methods. The results indicated only negligible differences between infestation levels (tree classes) with respect to Seifert cellulose and Klason lignin contents. In contrast, highly significant differences were observed for solvent- and water-borne extractives. It is evident from the results that P. patula trees engage a defence strategy to counter the effects of the infestation and the resulting physiological stress. The results of the chemical analyses suggest that trees should not be harvested any younger than the intended rotation age of 12 years and at the time of harvesting all the biomass, including the infected wood, should be sent to the pulp mill. Fire-damaged trees can be utilised in the same way as healthy trees when applying the TMP process provided the charcoal on the outer bark is removed. The usefulness of a biplot to simultaneously display the various tree classes and their chemical composition is illustrated.     

Laboratory evaluation and field application of bacterial and fungal insecticides on the citrus flower moth,Prays citri miller (Lep., hyponomeutidae) in lime orchards in Egypt

The efficacy of two commercial products of Bactospeine and Bio-fly onPrays citri of lime trees was studied under laboratory and field conditions throughout the two seasons of 1996 and 1997. Laboratory results indicated that the pathogenic effect of Bactospeine,Bacillus thuringiensis (Berliner) was higher than that of Bio-fly,Beauveria bassiana in spite of the latter was applied with higher doses. Bactospeine at the rate (2 cc/1 l.w.) effected on the larvae more than on the adults, that treatment reduced no. of eggs/female by 81.70% and decreased the larval infestation by 90.08%. Bio-fly at the highest concentration (4 cc/1 l.w.) reduced the infestation with the eggs, the larvae and the pupae by 65.83%, 68.45% and 72.55%, respectively. Advanced effects of bacterial and fungal treatments on the final reduction rates ofP. citri infestation were recorded. Field applications revealed that two sprays with Bactospeine or Bio-fly gave good control ofP. citri more than one spray. Bactospeine at the rate (2 cc/1 l.w.) and Biofly at the rate (4 cc/1 l.w.) reduced the infestation by (89.82–93.43%) and (76.32–78.83%), respectively. In all cases, higher doses of bioinsecticides produced potentiation effects of infestation reduction. It is recommended that two sprays of Bactospeine at a rate (2cc/1 l.w.) are adequate effective to reduce the population of P. citri in lime orchards during the main flowering period of trees without need of chemical insecticides. An erratum to this article is available at .     

Die Hymenopteren und Dipterenfauna in Pflanzungen dep Ölhaltigen Rose (Rosa damascena Mill.) in Bulagarien

Zusammenfassung Im Rahmen der z?nologischen Untersuchungen in den Pflanzungen derRosa damascena Mill. in Bulgarien wurden 128 Hymenopteren- und 64 Dipteren-Arten erfa?t. Nach der Ern?hrungsweise wurden die festgestelltenHymenoptera-Arten m sch?dliche, parasi?re, Pr?datoren und indifferente eingeteilt. Die sch?dlichen Arten wie auch 54 Arten Parasiten wurden auch unter Laborbedingungen bis zum Imago gezü chtet. Die T?tigkeit der Pr?datoren wurde durch unmittelbare Beobachtungen im Freien erfa?t. (Syrphidenarten wurden ebenfalls im Labor bis zum Imago gezüchtet). Die sch?dlichen Hymenopteren-Arten lassen sich in Abh?ngigkeit von ihrem trophischen Zusammenhang mit derRosa damascena Mill. in spezifische, st?ndige und zuf?llige Sch?dlinge (Nikolova, 1968) einteilen. Die Aphiden-Arten wurden den indifferenten Arten zugeordnet, weil die ?lhaltige Rose nicht zur Gewinnung der Früchte, sondern der Blüten angebaut wird. Trotzdem wird jedoch ihr Best?uberwert nicht untersch?tzt. Die Ergebnisse werden von z?nologischem. Aspekt diskutiert. Für die Bestimmung der Hymenoptera- und Dipteraarten m?chte ichJ, Pádr, J. Sédivy, M. Čapek, Z. Boucek, L. Masner, I. Ćepelak, M. Slamečkova, K. Samšiňák (Tschechoslovakische sozialistische Republik),A. Jelochovtsev, N. Talenge (UdSSR) undF. Mihályi (Ungarn) meinen Dank aussprechen.     

Influence of altitude on adult emergence and dynamics ofKaltenbachiola strobi (Winnertz) (Diptera: Cecidomyiidae) populations and its parasites in the Tatra National Park, Poland

A field study onKaltenbachiola strobi (Winnertz) (Diptera: Cecidomyiidae), was carried out between 1987 and 1993 in the highest mountain range in the Western Carpathians located within the Tatra National Park, in southern Poland. Rearing and analysis of 5 780 cones ofPicea abies (L.)Karst., collected from trees growing at different altitudes, yielded 30,478 individuals ofKaltenbachiola strobi, which infested 89.10% of the cones. In case of 29.81% of cones there were more than 20 larvae ofK. strobi per cone. It was shown thatK. strobi in the Tatra Mts. is more abundant in spruce stands of the upper mountain forest zone. Significant connections between the time of cone infestation byK. strobi and its parasitoids and characteristic phenophases in spruce foliage and cone development, and also the development of selected vegetation of the forest floor at different heights above sea level were determined. It was shown that the population dynamics ofK. strobi had tendency to alternate the increase and decrease in numbers every two years. It was also discovered that every two years spruce cones were inhabited by the population ofK. strobi with increased percentage of individuals having prolonged diapause. In total, the parasitoids reduced the population ofK. strobi by about 16–22.63%. Parasitism ofK. strobi in the lower mountain forest zone was higher than in the upper zone.Triplatygaster contorticornis Ratz. (Hymenoptera: Platygasteridae),Torymus azureus Boheman (Hymenoptera: Torymidae) andTetrastichus strobilanae Ratz. (Hymenoptera: Eulophidae) were most effiecient in reduction of the population ofK. strobi, and in the lower mountain forest zoneT. azureus was the dominant parasitoid species, while in the upper zoneT. contorticornis andT. strobilanae. It was shown that a considerable part of the populations ofT. azureus, T. contorticornis andT. strobilanae have their diapause prolonged and highly synchronized with the diapause of their host.     

Über die Wirkungen der sauren Niederschläge in Waldökosystemen

Zusammenfassung Die Theorie vonB. Ulrich über Wechselwirkungen zwischen sauren Niederschl?gen und natürlicher Bodenversauerung sowie potentielle Gefahren für die W?lder werden er?rtert. Eine Literaturübersicht und pers?nliche Beobachtungen des Verfassers vor allem in Süddeutschland führen zu dem Schlu?, da? Sch?den der sauren Niederschl?ge in Waldb?den bisher nicht nachgewiesen sind. Gro?fl?chige Kompensationskalkungen zur Vorbeugung werden zum jetzigen Zeitpunkt wegen der damit verbundenen Risiken abgelehnt. Dafür empfiehlt der Verfasser, die Emission der beteiligten Schadstoffe (SO₂, NO_x) in die Atmosph?re einzuschr?nken und die Forschung über die Wirkungen saurer Niederschl?ge in W?ldern zu intensivieren. Meliorationsma?nahmen sind nur auf solchen Standorten angezeigt, wo auch herk?mmliche Entscheidungskriterien dafür sprechen.

---

On the impact of acid precipitation of forest ecosystems

Summary The paper dicusses the theory ofB. Ulrich concerning the interactions of acid precipitation with natural soil acidification and the resulting potential dangers for forests. A literature review and personal oberservations made by the author mainly in southern Germany lead to the conclusion, that damaging effects of acid rain on forest soils so far are not yet documented. Liming operations on vast areas as a prophylactic measure presently are not recommended because of certain risks that are connected with this technique. Instead, the author suggests to reduce the emission of the pollutants involved (SO₂, NO_x) and to intensify basic investigations on the effects of acid rain in forests. Amelioration is only recommended for those soils, where conventional criteria support this decision.

     

New records of Phytophthora on trees in Britain

Phytophthora megasperma var. megasperma and unidentified isolates of Pbytophthora rescmbling P. cambivora were obtained from dead and dying roots of Horsc chestnut trccs with sparse foliage, small chlorotic leaves and branch dieback. P. citricola was isolatcd from soil around dead roots of similarly affected trccs and from around dcad feeder roots of a tree suffering from the common but unexplained Leaf scorch (marginal leaf necrosis) of Horse chestnut. Both P. cactorum and P. citricola were isolated from oozing acrial stem lesions on Horse chestnut trees. Inoculations with these species reproduced the damage.     

Insektenvermehrungen und Sonnenflecken

Zusammenfassung Die Befallsgeschichte nadelfressender Kiefernraupen (Bupalus piniarius L.,Panolis flammea Schiff.,Lymantria monacha L.,Dendrolimus pini L. undDiprion pini L.) in Süddeutschland (Regierungsbezirke Oberfranken, Mittelfranken, Oberpfalz und Pfalz) 1810–1970 wurde mit dem Verlauf der Sonnenflecken-Relativzahlen (Jahreswerte der Zürich'er Reihe) in Beziehung gesetzt. Nach den Ergebnissen von Korrelations-und Regressionsberechnungen besteht zwischen der Sonnenflecken-Aktivit?t und der St?rke des Insektenauftretens kein Zusammenhang. Gleiches gilt, venn die Lage der einzelnen Jahre innerhalb des Sonneflecken-Zyklus berücksichtigt wird: zwar hat es den Anschein, als ob besonders starke übervermehrungen von Spanner, Forleule und Nonne zwei Jahre nach einem Maximum der Relativzahlen folgen, doch ist diese Beziehung statistisch nicht gesichert.

---

Propagation of insects in relation to sunspot-activities

Summary Correlation and regression analyses were performed to investigate the coincidence of the outbreaks of pine defoliators with the sunspot cycle. Based on the data of five species (Bupalus piniarius L.,Panolis flammea Schiff.,Lymantria monacha L., Dendrolimus pini L. andDiprion pini L.) in four regions (administrative areas of Oberfranken, Mittelfranken, Oberpfalz and Pfalz) during the years of 1810–1970, there was no definite correlation between sunspot numbers and outbreak intensity of the pest species. Similarly, heavy infestations ofB. piniarius, P. flammea andL. monacha seem to occur two years following a sunspot maximum, but this condition is not significant statistically, and therefore, must be considered accidental.

---

---

Mit Unterstützung der Deutschen Forschungsgemeinschaft.

---

Meinem verehrten Lehrer, Herrn Prof. Dr. Dr.G. Wellenstein, zum 70. Geburtstag gewidmet.     

Holzbiologische Untersuchungen über den Einfluß von Auftausalz auf Hamburger Straßenbäume

Zusammenfassung Aus dem Stadtgebiet von Hamburg wurden 341 Stra?enb?ume der GattungenAcer, Aesculus, Betula, Fraxinus, Platanus, Quercus, Robinia, Sorbus undTilia hinsichtlich ihrer Empfindlichkeit gegenüber Streusalz untersucht. Als Untersuchungsmethoden dienten Jahrring-analyse sowie Histometrie und energiedispersive R?ntgen-Mikroanalyse. Auf Standorten mit hohem Bodensalzgehalt zeigten die meisten B?ume seit Mitte der 60er Jahre Zuwachsrückg?nge von über 50%, was zu einer Verringerung der wasserleitenden Querschnittsfl?che in den St?mmen und vermutlich zu den Blattnekrosen in der Krone führte. Alle an streusalzbelasteten Stra?en lebenden Ahornb?ume, Linden und Ro?kastanien zeigten eine starke Vitalit?tsminderung. Lediglich die Eichen und Robinien lassen keine streusalzbedingten Wachstums?nderungen erkennen. Zur Erholung der gesch?digten B?ume sowie zur Sicherung der toleranten Baumarten müssen eine weitere Salzzufuhr verhindert und die bereits angereicherten Salzmengen aus dem Kreislauf Boden-Baum-Boden entfernt werden.

---

Wood-biological investigations on the influence of deicing salt on roadside trees in Hamburg

Summary From the urban area of Hamburg, 341 roadside trees of the generaAcer, Aesculus, Betula, Fraxinus, Platanus, Quercus, Robinia, Sorbus andTilia have been investigated concerning their sensitivity to deicing salt. The methods used were tree-ring analysis, histometrical studies, and X-ray microanalysis. Since the middle of the Sixties the radial growth of most tress decreased more than 50% on all sites with a high salt content in the soil, leading to a reduction of the water-conducting area in the stems. The necrosis of the leaves is presumably a result of this situation. All maples, horsechestnuts, and limes growing along roads affected by deicing salt showed a highly decreased vitality. Only oak and black locust do not exhibit any saltinfluenced growth responses. For the recovery of the injured trees as well as for safeguarding the more tolerant tree species a further salt transport to the roots must be prevented, and the amount of salt already accumulated must be removed from the soil-tree-soil cycle.

---

---

Wir danken Dr.H. Meyer-Spasche, Ordinariat für Bodenkunde der Universit?t Hamburg, für die Bereitstellung der bodenchemischen Standortsdaten, Prof. Dr.N. Parameswaran für die energiedispersive R?ntgen-Mikroanalyse sowie Frau Dipl.-HolzwirtS. Wrobel und FrauF. Quiehl für ihre Mithilfe bei der Laborauswertung. Die Arbeit wurde von der Beh?rde für Bezirksangelegenheiten, Naturschutz und Umweltgestaltung (BBNU) der Freien und Hansestadt Hamburg finanziell unterstützt. Die Baubeh?rde stellte Informationen über die Intensit?t der Streusalzanwendung zur Verfügung.     

Über das Auftreten vonTrogoderma glabrum (Herbst) als Vorratsschädling in Deutschland und das Vorkommen anderer schädlicherTrogoderma-Arten

Zusammenfassung Es wird über das erstmalige Auftreten vonTrogoderma glabrum (Herbst) als Vorratsschädling in West-Berlin und der Bundesrepublik berichtet. Befallen waren vor allem Sackstapellager von Trockenkartoffeln und Reis. Unter den in West-Berlin herrschenden Klima- und Lagerbedingungen erreichte der Schädling bisher in den Lägern erst im Laufe mehrerer Jahre eine wesentliche Befallsstärke. Ferner wird ein Überblick über das Vorkommen anderer schädlicher Arten der GattungTrogoderma unter Berücksichtigung der deutschen Verhältnisse gegeben.

---

Summary First records ofTrogoderma glabrum (Herbst) as a pest of stored products in Western-Berlin and the Federal Republic of Germany are given. The commodities infested were specially rice and dried potatoes stored in paper or jute bags. Under the climatic and storage conditions of Western-Berlin the pest could reach an essential grade of infestation only after several years. A review of the occurrence of other harmful species of the genusTrogoderma especially with respect to the situation in Germany is added.

     

The distribution of Phratora vulgatissima (Coleoptera: Chrysomelidae) on cultivated willows in Britain and Ireland

Insect samples were collected from the canopy of 24 willow short rotation coppice (SRC) sites on farmland in Britain and Ireland in 1995. The blue willow beetle Phratora (= Phyllodecta) vulgatissima (L.) (Coleoptera: Chrysomelidae), previously identified as the main defoliating pest of this crop, was recorded from 13 of these at varying levels of abundance. Data describing aspects of the environment at each site were also collected. These data were used to create potential explanatory variables for a regression analysis of beetle abundance. This analysis indicated that P. vulgatissima were most likely to occur and were more abundant at older willow sites on clay soils and at sites that bad certain free-living willow species growing nearby. Within sites, most willow clones sampled contained P. vulgatissima, although two, Salix burjatica‘Germany’ (‘Aquatica Gigantea’) and Salix mollissima‘Q83’ (Salix triandra × Salix viminalis), were avoided. Chrysomelid pest avoidance and clonal resistance could form part of an integrated pest management strategy for SRC crops.     

Growth response to the stress of low osmotic potential,salinity and high pH in cultured shoot of Chinese poplars

In vitro cultured shoots of three Chinese poplar species (Populus tomentosa, P. alba cv. Pyramidalis andP. euphratica) and an improved poplar (FS-51), as a control, were exposed to the stress of low osmotic potential, salinity and high pH, and the shoot growth was measured.P. tomentosa andP. euphratica could grow even under the high osmotic stress (0.5m mannitol; −1.7 MPa).P. euphratica shoots which were previously cultured on the medium containing 0.7m mannitol (−2.4 MPa) recovered its growth after being transplanted to the medium without mannitol. The shoot growth ofP. euphratica was not so reduced even on the medium containing 100 mM NaCl. However, growth of the other poplars markedly reduced with 10 mM NaCl. Medium pH (pH 5.8–10) also did not affect the shoot growth ofP. euphratica. These poplars have different tolerance to the stresses in cultured shootin vitro. P. euphratica was extremely tolerant to the stresses which are possible to damage plants in dry land. A part of this study was presented at the 104th Annual Meeting of the Japanese Forestry Society. (1993).