Kenntnis der Vermehrungspotenz und des Massenwechsels von Getreideblattläusen als Voraussetzung zur Prognose und gezielten Bekämpfung

Wetzel, D.; Freier, H.

doi:10.1080/03235407509431164

Cited by 16 publications

(4 citation statements)

References 9 publications

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“…Early season abundance of 2.4 R. padi per plant and late season abundance of 1.5 per plant reduced yield by 0.5 and 0.6 tlha, respectively. This R. padi abundance is similar to threshold levels for aphid control established in other regions (Kieckhefer and Gellner 1992;Larsson 1991;Wetzel and Freier 1975). Winter cereal producers in Nova Scotia can expect yield reductions if no chemical controls are used.…”

Section: Impact Of Selected Pesticides and Insects On Yieldsupporting

confidence: 76%

CONTROL OF THE ENGLISH GRAIN APHID [SITOBION AVENAE (F.)] (HOMOPTERA: APHIDIDAE) AND THE OAT-BIRDCHERRY APHID [RHOPALOSIPHUM PADI (L.)] (HOMOPTERA: APHIDIDAE) ON WINTER CEREALS

Neil¹,

Gaul

McRae

1997

Can Entomol

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The Canadian Entomologist 129: 1059 -1065 (1997) Laboratory assays and field surveys showed that Ascosphaera lawis (Bissett) is a pathogen of alfalfa leafcutting bee larvae, capable of causing high mortality in commercial populations. In one population, over 21% of bees were found to be infected by A. larvis. However, overall levels of the disease are low and it is unlikely that this pathogen poses an immediate threat to commercial leafcutting bee populations in Canada. The LD,, was determined to be 1.9 x 10' sporeshee. Elevated levels of CO, are required for in vitro spore germination. The disease can easily be diagnosed within bee cells by X-ray radiography, thereby enabling disease levels to be monitored using conventional methods utilized by the industry to monitor leafcutting bee quality. Goettel, M.S., D.W. Goerzen et G.M. Duke. 1997. PropriCtCs pathogkues d'ilscosphaera larvis pour les larves de la dkcoupeuse de la luzeme, Megachile rotundata. The Canadian Entomologist 129 : 1059-1065.Des Ctudes en laboratoire ont dCmontrC qu'Ascosphaera larvis (Bissett) est un pathogkne des larves de la dCcoupeuse de la luzerne, capable d'occasionner une mortalit6 importante au sein des populations commerciales. Chez une population examinCe, plus de 21% des abeilles Ctaient infectCes par A. larvis. Cependant, la maladie s'est avCrCe gCnCralement bCnigne et le pathogkne ne constitue donc pas une menace immCdiate pour les populations commerciales de dCcoupeuses au Canada. Le LD,, a Ct C CvaluC 2 1,9 x 10' spores/abeille. Des concentrations ClevCes de CO, sont essentielles h la germination des spores in vitro. La maladie est facilement diagnostiquke dans les cellules des abeilles par radiographie aux rayons X, ce qui permet d'en Cvaluer la gravitC au moyen des mkthodes conventionnelles utilisCes industriellement pour apprCcier la qualit6 des abeilles.[Traduit par la RCdaction]

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Section: Impact Of Selected Pesticides and Insects On Yieldsupporting

confidence: 76%

CONTROL OF THE ENGLISH GRAIN APHID [SITOBION AVENAE (F.)] (HOMOPTERA: APHIDIDAE) AND THE OAT-BIRDCHERRY APHID [RHOPALOSIPHUM PADI (L.)] (HOMOPTERA: APHIDIDAE) ON WINTER CEREALS

Neil¹,

Gaul

McRae

1997

Can Entomol

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“…The possibility a mass reproduction is given and as a result of it there is a great damage caused by this species. Consequently biological investigations of ROSTRUP and THOMSEN (1931), WETZEL and FREIER (1975), VICKERMAN and WRATTEN (1975) prove damage, too. Parallel with mass reproduction there is an enlarged role of aphides as virus vectors and as the data of scientific literature show (FRITZSCHE et al 1972;HORVATH 1972;ROCHOV and ISRAEL 1977;HUTH 1979) in spreading viruses epidemically.…”

Section: Discussionmentioning

confidence: 99%

“…As a result of aphids nourishing there is a great loss in yield which has important aspects in quality and quantity (KOLBE 1973;WRATTEN 1978;HINZ and DEABELER 1980). In Denmark, Norway and Central Europe it has caused a big damage since 1968 (WETZEL and FREIER 1975). Its importance was reported by VICKERMAN and WRATTEN (1979) concerning whole Europe.…”

Section: Introductionmentioning

confidence: 94%

Laboratory investigation of the ontogenesis of oat aphis (Rhopalosiphum padi L.)

Kuroli

1984

Zeitschrift für Angewandte Entomologie

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For clearing up ontogenesis and reproduction of Rhopalosiphum padi L. experiments were carried out in a climate chamber and the period of larvae development, the number of offsprings of the parthenogenetic individuals and the possibility of anholocyclic development were determined. During investigations development of larvae to parthenogenetic ones was evaluated at three different temperatures (17, 21, 25 °C) and stated that the development threshold temperature was 3.3 °C. On its base the effective total heat was calculated that was 187.6 °C in average. Development period of the larvae at 21 °C was 8.2–9.6 days. Deviation of larvae grades was investigated and stated that the lifetime of the first grade larvae was the shortest (1.5 days) and that of third grade larvae was the longest (2.7 days). The lifetime of the imagos was 17.7 days in average with a praereproduction period of 0.3, reproduction period of 16.9 and postreproduction period of 0.5 days. The number of the offsprings was 27–93, the average was 69.9. Considering average offspring number and lifetime of imagos it was stated that larvae born daily were 3.8. In clearing up anholocyclic development set up in refrigerators it was proved that the resistance of differently developed individuals without acclimatization was divergent. Nymphs died on the 14th, wingless on the 12th, L1 larvae on the 11th, L2 larvae and wingless parthenogenetic ones on the 9th and L3 L4 larvae on the 7th day. Investigations proved that anholocyclic development of Rh. padi is possible in Hungary in mild winters. Zusammenfassung Laboratoriums‐Untersuchungen zur Ontogenese der Haferblattlaus (Rhopalosiphum padi L.) Es wurden Klimakammeruntersuchungen durchgeführt, um die Ontogenese und Fortpflanzungsfähigkeit von Rhopalosiphum padi festzustellen. Dabei wurden die Dauer der Larvenentwicklung, die Zahl der Nachkommen der parthenogenetischen Weibchen und die Möglichkeit der anholozyklischen Entwicklung betrachtet. Die Entwicklung der Larven zu parthenogenetischen Weibchen erfolgte bei 3 verschiedenen Temperaturen (17, 21, 25°C). Die Temperaturschwelle lag bei 3,3°C. Auf dieser Grundlage wurde die effektive Wärmesumme berechnet, die im Durchschnitt 187,6°C betrug. Die Entwicklungsperiode der Larven bei 21°C betrug 8,2–9,6, im Durchschnitt 9,1 Tage. Es wurde die Differenz zwischen den einzelnen Larvenstufen untersucht. Die Lebensdauer des 1. Larvenstadiums war am kürzesten (1,5 Tage), die des 3. Stadiums am längsten (2,7 Tage). Die Imagines lebten im Mittel 17,7 Tage, wovon 0,3 auf die Praereproduktions‐, 16,9 auf die Reproduktions‐ und 0,5 auf die Postreproduktionsphase entfielen. Die Zahl der Nachkommen pro Weibchen betrug 27–93, im Mittel 69,9. Auf Grund der mittleren Nachkommenzahl und der Lebensdauer der Imagines wurde festgestellt, daß die mittlere Zahl der täglich geborenen Larven 3,8 betrug. Die Kühlschrankuntersuchungen zeigten, daß die Widerstandsfähigkeit der verschiedenen Entwicklungsformen ohne Akklimatisation verschieden war: Die Nymphen starben am 14., die Aptere...

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“…Im Hinblick auf den Einsatz von Insektiziden im Getreideanbau bestehen zwischen beiden Agrarräumen gravierende Unterschiede. Auf den Großflächen um Barnstädt und Peißen konnte durch Beachtung eines Bekämpfungsrichtwertes von 3-5 Aphiden/ Ähre (Freier, 1975;Wetzel und Freier, 1975) eine Insektizidapplikation in den meisten Jahren unterbleiben. In den letzten beiden Jahrzehnten kam es lediglich zu 2 Blattlausbekämpfungen.…”

Section: Vergleichende öKologische Studien Auf Groß-und Kleinflächenunclassified

Mit dem integrierten pflanzenschutz ins neue jahrtausend*

Wetzel

Volkmar

Hussein

et al. 2000

Archives Of Phytopathology And Plant Protection

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Kenntnis der Vermehrungspotenz und des Massenwechsels von Getreideblattläusen als Voraussetzung zur Prognose und gezielten Bekämpfung

Cited by 16 publications

References 9 publications

CONTROL OF THE ENGLISH GRAIN APHID [SITOBION AVENAE (F.)] (HOMOPTERA: APHIDIDAE) AND THE OAT-BIRDCHERRY APHID [RHOPALOSIPHUM PADI (L.)] (HOMOPTERA: APHIDIDAE) ON WINTER CEREALS

CONTROL OF THE ENGLISH GRAIN APHID [SITOBION AVENAE (F.)] (HOMOPTERA: APHIDIDAE) AND THE OAT-BIRDCHERRY APHID [RHOPALOSIPHUM PADI (L.)] (HOMOPTERA: APHIDIDAE) ON WINTER CEREALS

Laboratory investigation of the ontogenesis of oat aphis (Rhopalosiphum padi L.)

Mit dem integrierten pflanzenschutz ins neue jahrtausend*

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