The time of flight and the relative importance of Myzus persicae (Sulz.) and Aphis fabae Scop. in relation to the incidence of beet yellows as shown by trap catches at Rothamsted and Broom's Barn

1966 ◽  
Vol 56 (3) ◽  
pp. 473-480 ◽  
Author(s):  
G. D. Heathcote
Keyword(s):  
Sugar Beet ◽  
Myzus Persicae ◽  
Time Of Flight ◽  
Aphis Fabae ◽  
Relative Importance ◽  
Experimental Station ◽  
Large Numbers ◽  
Rothamsted Experimental Station ◽  
Trap Catches ◽  
Aphid Abundance

Sticky traps were operated over sugar-beet crops at Rothamsted Experimental Station (Hertfordshire), Broom's Barn Experimental Station (Suffolk) and elsewhere for five years to gain information about the flight of the aphids that transmit beet yellowing viruses and to aid in the spray warning scheme for sugar-beet growers.Numbers of Myzus persicae (Sulz.), Aphis fabae Scop, and of all aphids caught per week are given. Records of aphids trapped at Rothamsted over a period of 23 years have been published; but no repeating pattern of aphid abundance from year to year has been detected. M. persicae flew early in 1960 and 1961, when beet viruses spread extensively, whereas in 1962, 1963 and 1964, when alates of this species did not fly early but were trapped in relatively larger numbers later in the year, yellows spread much less. Large numbers of A. fabae flew in 1963, but beet viruses spread little.

Aphids caught on sticky traps in eastern England in relation to the spread of yellowing viruses of sugar-beet

1974 ◽  
Vol 64 (4) ◽  
pp. 669-676 ◽  
Author(s):  
G. D. Heathcote
Keyword(s):  
Sugar Beet ◽  
Myzus Persicae ◽  
Annual Incidence ◽  
Aphis Fabae ◽  
General Increase ◽  
Sticky Traps ◽  
Linear Regressions

AbstractLong-term records of aphid catches on two sticky traps, one at Rothamsted (1942–64) and one at Broom's Barn (1960–64) are extended to 1973 and are supplemented by data from up to 12 sticky traps in sugar-beet crops in eastern England (1960–73). The incidence of yellowing viruses of sugar-beet between 1965 and 1973 showed no relation to aphid numbers, but between 1942 and 1973 the pattern of annual incidence was similar to that of numbers of Myzus persicae (Sulz.) trapped in May and June. Linear regressions of the incidence of yellowing viruses on numbers of M. persicae in May and June accounted for 28–57% of the variance, and on Aphis fabae group for 2–40% of the variance. It is concluded that sticky traps provide useful information for advisory entomologists and that there has been no general increase in aphid numbers over the last 30 years.

Observations on the settling behaviour of aphids on sugar–beet plants in the glasshouse

1966 ◽  
Vol 67 (3) ◽  
pp. 405-410 ◽  
Author(s):  
G. E. Russell
Keyword(s):  
Sugar Beet ◽  
Myzus Persicae ◽  
Aphis Fabae ◽  
Settling Behaviour

1. In glasshouse experiments, apterous and alate Myzus persicae Sulz. and Aphis fabae Scop, settled more readily on some sugar-beet plants than on others.

Динамика численности и видовой состав тлей на посадках семенного картофеля в Ленинградской области

2020 ◽  
pp. 3-7
Author(s):  
Тамара Алексеевна Шелабина ◽  
Марина Николаевна Берим
Keyword(s):  
Myzus Persicae ◽  
Aphis Fabae ◽  
Aphis Nasturtii

Существенным элементом в комплексе специальных и агротехнических приемов, направленных на ограничение распространения вирусной инфекции, является мониторинг численности, динамики и видового состава тлей, мигрирующих в посадках оригинального картофеля. Двухлетний мониторинг (2016 – 2017 гг.) на опытных полях Гатчинского района Ленинградской области проведен с использованием желтых водных ловушек Мёрике. Изучены количество тлей, сроки их миграции на посадки картофеля, сроки наступления пика численности. Наибольшее влияние на насекомых оказывала среднесуточная температура воздуха. За сезон наблюдений отловлено: в 2016 г. — 481 крылатая особь 31 вида, в 2017 г. — 131 особь 30 видов. Доля возможных переносчиков вирусов картофеля от общего числа зарегистрированных крылатых тлей составила в 2016 г. 14,8 %, в 2017 г. — 32,8 %. Оценка скрытой зараженности вирусной инфекцией (MBK, YBK вирусы) методом ИФА в 2015 – 2017 гг. показала, что на растениях картофеля сорта Ломоносовский скрытая зараженность составила 2,6 – 7,3 %, сорта Чародей — 1,9 – 13,3 %, сорта Невский — 0,8 – 10,5 %, сорта Романо — 4,1 – 9 %. Из известных переносчиков вирусов картофеля в оба года в энтомологических сборах с сосудов отмечены Aphis nasturtii — 6 – 12,2 %, Aphis fabae — 7,2 – 4,6 % от общего числа отловленных; Myzus persicae (13 %) в составе мигрирующей генерации тлей отмечены только в дождливом и прохладном 2017 г. В прогностических целях желательно пользоваться в регионе также данными со всасывающей ловушки, поскольку появление в ней насекомых отмечено на 10 – 12 дней раньше, чем на полях.

Negotiations over Accounting Issues: The Congruency of Audit Partner and Chief Financial Officer Recalls

2005 ◽  
Vol 24 (s-1) ◽  
pp. 171-193 ◽  
Author(s):  
Michael Gibbins ◽  
Susan A. McCracken ◽  
Steven E. Salterio
Keyword(s):  
Negotiation Process ◽  
Chief Financial Officers ◽  
Chief Financial Officer ◽  
Relative Importance ◽  
Common Elements ◽  
Contextual Features ◽  
Large Numbers ◽  
The Common ◽  
High Level ◽  
Two Sides

Much of what takes place in auditor-client management negotiations occurs in unobservable settings and normally does not result in publicly available archival records. Recent research has increasingly attempted to probe issues relating to accounting negotiations in part due to recent events in the financial world. In this paper, we compare recalls from the two sides of such negotiations, audit partners, and chief financial officers (CFOs), collected in two field questionnaires. We examine the congruency of the auditors' and the CFOs' negotiation recalls for all negotiation elements and features that were common across the two questionnaires (detailed analyses of the questionnaires are reported elsewhere). The results show largely congruent recall: only limited divergences in recall of common elements and features. Specifically, we show a high level of congruency across CFOs and audit partners in the type of issues negotiated, parties involved in resolving the issue, and the elements making up the negotiation process, including agreement on the relative importance of various common accounting contextual features. The analysis of the common accounting contextual features suggests that certain contextual features are consistently important across large numbers of negotiations, whether viewed from the audit partner's or the CFO's perspective, and hence may warrant future study. Finally, the comparative analysis allows us to identify certain common elements and contextual features that may influence both audit partners and CFOs to consider the accounting negotiation setting as mainly distributive (win-lose).

Dispersal of the sugar-cane scale Aulacaspis tegalensis (Zhnt.) (Hem., Diaspididae) by air currents

1972 ◽  
Vol 61 (3) ◽  
pp. 547-558 ◽  
Author(s):  
D. J. Greathead
Keyword(s):  
Sugar Cane ◽  
Laboratory Experiments ◽  
Sticky Trap ◽  
Research Station ◽  
High Humidity ◽  
Dispersal Mechanism ◽  
Large Numbers ◽  
Speed Up ◽  
Trap Catches ◽  
Aulacaspis Tegalensis

By means of sticky traps and a suction trap, it was demonstrated on a plot of sugar-cane at Kawanda Research Station, Uganda, that large numbers of crawlers of Aulacaspis tegalensis (Zhnt.) become airborne (up to 10/m3). The numbers increase with wind speed up to about 2·0 m/s and then remain constant, but are depressed by increasing humidity. In laboratory experiments, crawler survival was reduced by high temperatures (30°C) and low humidities (30% r.h.), but some individuals should survive the extreme conditions sometimes experienced if airborne from morning until evening. On hatching, crawlers move upwards and towards the light, but downwards in the dark; movement is inhibited by high humidity. These behaviour responses indicate hat the presence of crawlers in the air is not accidental but a dispersal mechanism. At Arusha Chini, an isolated sugar estate in Tanzania, sticky-trap catches downwind of a windbreak confirmed that airborne dispersal of crawlers is a major source of infestation. It is shown that air currents could have carried crawlers to Arusha Chini from a source on the Kenya coast, 260 km to the east.

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