Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Life histories of an invasive and native ladybird under field experimental conditions in a temperate climate
Raak-van den Berg, C.L. ; Jong, Peter W. de; Gort, Gerrit ; Manly, Bryan F.J. ; Lenteren, Joop C. van - \ 2018
Entomologia Experimentalis et Applicata 166 (2018)3. - ISSN 0013-8703 - p. 151 - 161.
Harmonia axyridis - Adalia bipunctata - Coccinellidae - Coleoptera - Competition between species - Field experimental study - Immature development - Immature survival - Intraguild predation - Life table - Northwestern Europe - Tilia × europaea
Among characteristics that are thought to determine the success of invasive species, life-history traits feature prominently. However, in most cases, these have been determined under laboratory conditions. Here, we use a field set-up to determine immature development time and survival of invasive Harmonia axyridis (Pallas) and native Adalia bipunctata L. (both Coleoptera: Coccinellidae). On caged Tilia × europaea L. cv. Pallida trees (Malvaceae) with ample amounts of aphid food, we introduced freshly hatched larvae of a single or of both ladybird species and followed their development until emergence of adults. Under the condition of ample prey availability, both ladybird species apparently hardly interacted and intraguild predation did not cause significant mortality. Development time of both species is in line with data from laboratory tests under controlled conditions. Immature survival can reach high levels, but is considerably higher for H. axyridis (44-100%) than for A. bipunctata (11-77%), resulting in faster increase of H. axyridis populations, which is one of the factors that may explain its invasion success.
Flevo –land in beweging
Egmond, Fenny van - \ 2017
RAAK-PRO
Electronic supplementary materials of: Did the life history of multicoloured Asian ladybird, Harmonia axyridis, change when it spread across the globe? A meta ‐ analysis
Raak-van den Berg, C.L. - \ 2017
Parasites of Harmonia axyridis: current research and perspectives
Haelewaters, D. ; Zhao, S.Y. ; Clusella-Trullas, S. ; Cottrell, T.E. ; Kesel, A. De; Fiedler, L. ; Herz, A. ; Hesketh, H. ; Hui, C. ; Kleespies, R.G. ; Losey, J.E. ; Minnaar, I.A. ; Murray, K.M. ; Nedved, O. ; Pfliegler, Walter P. ; Raak-van den Berg, C.L. ; Riddick, E.W. ; Shapiro-Ilan, D.I. ; Smyth, R.R. ; Steenberg, T. ; Wielink, P.S. van; Viglasova, S. ; Zhao, Z. ; Ceryngier, P. ; Roy, H.E. - \ 2017
BioControl 62 (2017)3. - ISSN 1386-6141 - p. 355 - 371.
017-4067
Harmonia axyridis (Coleoptera: Coccinellidae) has been introduced widely for biological control of agricultural pests. Harmonia axyridis has established in four continents outside of its native range in Asia and it is considered an invasive alien species (IAS). Despite a large body of work on invasion ecology, establishment mechanisms of IAS and their interactions with natural enemies remain open questions. Parasites, defined as multicellular organisms that do not directly kill the host, could potentially play an important role in regulating host populations. This study presents a review of the parasites of H. axyridis, discussing their distributions and effects on host populations across the host’s native and invasive range. These parasites are: Hesperomyces virescens Thaxt. fungi, Coccipolipus hippodamiae (McDaniel and Morrill) mites, and Parasitylenchus bifurcatus Poinar and Steenberg nematodes.
Life history of the harlequin ladybird, Harmonia axyridis : a global meta-analysis
Raak-van den Berg, C.L. ; Hemerik, Lia ; Werf, Wopke van der; Jong, Peter W. de; Lenteren, Joop C. van - \ 2017
BioControl 62 (2017)3. - ISSN 1386-6141 - p. 283 - 296.
Coccinellid - Harmonia axyridis - Invasive populations - Life history characteristics - Meta-analysis - Native area - Temperature dependence
The harlequin ladybird, Harmonia axyridis, is an important natural enemy of aphids throughout the world, but is now also considered an invasive alien species. We performed a meta-analysis of published life history data to address the question whether invading populations in Europe and North America have life history parameters that differ from native populations in Asia, explaining the beetle’s invasion success in new territories. In this meta-analysis, we accounted for important covariables that are often reported in published studies such as temperature, food source (aphids or eggs of Ephestia kuehniella), strain (laboratory or field populations) and photoperiod. Temperature was a key factor having consistent large effects on development rate, survival and reproductive characteristics of H. axyridis. Food source, strain, and photoperiod had effects on some, but not all characteristics, and their overall effect across characteristics was minor. Individuals of invasive populations had a shorter pre-oviposition period and higher fecundity at low temperatures than those of native populations, and a greater longevity across all temperatures. No differences in survival were found between native and invasive populations, while differences in development rate were not consistent, with opposing results obtained according to the way development rate was measured in trials reported in the literature. Results of this meta-analysis support the hypothesis that the life history of the beetle has changed during its invasion into North America and Europe. Invasive populations had a shorter pre-oviposition period and higher fecundity at low temperatures, as well as a greater longevity across all temperatures than native populations. These differences may partially explain the invasive success of H. axyridis.
Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis
Raak-van den Berg, C.L. ; Hemerik, A. ; Werf, W. van der; Jong, P.W. de; Lenteren, J.C. van - \ 2017
meta-analysis - invasive populations - Harmonia axyridis - life history characteristics - temperature dependence - native area - coccinellid
Data collected en used for a meta analysis on life history data of H. axyridis. And the resulting 20 best models for each life history characteristic. Published in the paper: Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis.
De Amsterdamse haven draait (groen) door : Op weg naar duurzaam concurrentievoordeel door inzet op de biobased en circulaire economie
Kuipers, Bart ; Jong, Onno de; Raak, Roel van; Sanders, Frederic ; Meesters, Koen ; Dam, J.E.G. van - \ 2015
Wageningen UR - Food & Biobased Research - 112 p.
regionale economie - regionale ontwikkeling - economische ontwikkeling - kringlopen - biobased economy - havens - amsterdam - noord-holland - regional economics - regional development - economic development - cycling - harbours
In dit onderzoek is de haven van Amsterdam nader onderzocht, zijn kansen voor de ontwikkeling van zowel biobased als circulaire economie in kaart gebracht en worden 17 acties benoemd voor het Havenbedrijf Amsterdam om deze kansen te kunnen verzilveren. De auteurs concluderen dat er grote kansen zijn voor de haven van Amsterdam om de transitie naar duurzame toepassingen in de biobased en circulaire economie door te zetten, met name voor biodiesel en -gas en bouwstenen voor de biochemie. Deze kansen blijken voorts uit de sterke knooppuntfunctie van de haven: er is reeds een aantal krachtige logistieke spelers aanwezig dat zich actief bezig houdt met de behandeling van biodiesel, maar vooral de reeds bestaande agrostromen hebben potentie voor toepassing in biobased routes. Tevens is een aantal logistieke spelers actief in schroot en andere vormen van recycling in de haven aanwezig—de schroothandel laat zien dat de circulaire economie zich steeds meer op een internationaal schaalniveau ontwikkelt waarbij de inzet van zeehavens onontbeerlijk is.
Harmonia axyridis: how to explain its invasion success in Europe
Raak-van den Berg, C.L. - \ 2014
Wageningen University. Promotor(en): Joop van Lenteren, co-promotor(en): Peter de Jong; Lia Hemerik. - Wageningen : Wageningen University - ISBN 9789462571037 - 221
harmonia axyridis - organismen ingezet bij biologische bestrijding - geïntroduceerde soorten - invasieve exoten - predatie - voedingsgedrag - nederland - harmonia axyridis - biological control agents - introduced species - invasive alien species - predation - feeding behaviour - netherlands

Abstract of the thesis entitled “Harmonia axyridis: how to explain its invasion success in Europe”

After introduction as biological control agent of aphids, the multicoloured Asian ladybird Harmonia axyridis has established and spread in Europe. Harmonia axyridis is now regarded as an invasive species because its establishment had negative effects on non-target species, fruit production, and human health. Life history characteristics were studied in order to find an explanation for its invasion success.

With a meta-analysis I showed that life-history traits of H. axyridis differed between Asian and invasive populations of H. axyridis. However, the greatest differences in development rate were observed at temperatures above 24°C, while at temperatures characteristic for spring and summer in northwestern Europe (17 to 24°C) invasive populations of H. axyridis do not differ from native Asian populations; thus, the invasive success cannot be attributed to a change in life history characteristics of the invasive population. Compared to native species European ladybirds (Adalia bipunctata, Coccinella septempunctata, and Propylea quatuordecimpunctata), H. axyridis develops slower and starts reproduction later, suggesting no competitive advantage for the invader.

Additionally, life history characteristics were studied under field conditions. I showed that in northwestern Europe H. axyridis has a period of real diapause starting at the end of October and shifts to a quiescent state in December. This diapause is relatively short and weak compared with published data of native ladybirds. Moreover, it appears to have become shorter over the last decade. Thus, H. axyridis can become active rapidly when temperature rises in spring, but, nevertheless, it is not reported to be active earlier in the year than native species.

Overwintering survival of H. axyridis in the Netherlands is between 71 and 88%. At five sample sites I found that ladybirds that were hibernating at the southwestern sides of buildings, where most aggregations of ladybirds were found, had a higher winter survival than ladybirds hibernating at other orientations. At sheltered sites survival was higher compared to exposed sites. A high overwintering survival results in a large post-hibernation population and a rapid population build-up in spring. Compared with most common native species, winter survival of H. axyridis is similar or higher.

In this research, i.e. under semi-field conditions, immature survival of H. axyridis and A. bipunctata reached high levels, but survival was generally considerably higher for H. axyridis than for the native A. bipunc­tata. Under semi-field conditions with high food availability, no effect of the presence of H. axyridis on the survival, development, weight, and size of the native species A. bipunctata was found. Under natural conditions, however, situations of prey scarcity do occur, as aphid colonies are relatively short-lived.

Additionally, I demonstrated that in absence of food under semi-field conditions, intraguild predation between C. septempunctata, A. bipunctata, and H. axyridis does occur, although the contact frequency is low. When two fourth instar larvae were placed together on a single leaf, at least one contact was made in 23–43% of the observations, depending on the tested species combination. When contacts between ladybirds do occur, H. axyridis larvae are the winners in contacts with larvae of the native species.

Finally, I found that several natural enemies are starting to use H. axyridis as a host but are as yet not sufficiently abundant and/or effective to have a profound impact on populations of the invader. In the years 2003—2007 no natural enemies were found in ladybird samples. From 2008 onwards H. axyridis adults were infested by: Hesperomyces virescens fungi (summer and winter), Parasitylenchus bifurcatus nematodes (winter), Coccipolipus hippodamiae mites (winter), and Dinocampus coccinellae parasitoids (summer and winter).

Summarising, the success­ful invasion of H. axyridis in the Netherlands cannot be explained by a change of the invasive H. axyridis populations in comparison with the native Asian population, but by a combi­nation of several characteristics: overwintering, immature survival, fecundity, longevity, number of generations per year, and intraguild predation. In comparison with native European ladybird species, H. axyridis survives better (in winter and the immature stages), it lays more eggs, has more generations per year, and lives longer: this results in a faster population growth than that of native ladybirds. Harmonia axyridis can potentially easily outnumber native species within a few years. Moreover, H. axyridis being a strong intra­guild predator, the slow immature development and late arrival at aphid colonies com­pared to native species is compensated by the ability of H. axyridis to feed on eggs, larvae, and pupae of other ladybirds, thereby completing its development.

However, several facts, e.g. the quite stable diversity and abundance of ladybird species in Asia and the first evidence that natural enemies attack H. axyridis, suggest that the current situation in Europe may not be the terminal stage, but a transition to a new balance where native species are strongly reduced in abundance, but do not become extinct.

Invasive alien species under attack: natural enemies of Harmonia axyridis in the Netherlands
Raak-van den Berg, C.L. ; Wielink, P. van; Jong, P.W. de; Gort, G. ; Haelewaters, D. ; Helder, J. ; Lenteren, J.C. van - \ 2014
BioControl 59 (2014)2. - ISSN 1386-6141 - p. 229 - 240.
coleoptera-coccinellidae - ladybird beetle - pallas coleoptera - fungus - laboulbeniales - europe - north - amplification - populations - prevalence
The aphid predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is an invasive alien species in Europe and North America with negative effects on non-target species (including a decline of native ladybird populations), as well as fruit production, and human health. It is, therefore, important to find out which natural enemies could be used to reduce their numbers. Knowledge of H. axyridis’ natural enemies is summarised and data collected from the Netherlands over the past ten years are presented. Beetles were sampled from winter aggregations and from spring through to autumn with illuminated screens at night. Natural enemies were not found in samples of H. axyridis from 2003–2007. From 2008 onward H. axyridis adults were infested by: Hesperomyces virescens Thaxt. fungi (summer and winter), Parasitylenchus bifurcatus Poinar and Steenberg nematodes (winter), Coccipolipus hippodamiae (McDaniel and Morrill) mites (winter), and Dinocampus coccinellae (Schrank) parasitoids (summer and winter). Our results indicate that these natural enemies are starting to use H. axyridis as a host, but are as yet not sufficiently abundant to control the population.
Verslag studiereis aquacultuur Spanje
Hiele, T. van der; Malta, E.J. ; Heringa, J. ; Houcke, J. van - \ 2013
Aquacultuur 28 (2013)2. - ISSN 1382-2764 - p. 20 - 27.
aquacultuur - zeeaquacultuur - marien milieu - viskwekerijen - algenteelt - schaal- en schelpdierenteelt - schaal- en schelpdierenvisserij - spanje - aquaculture - marine aquaculture - marine environment - fish farms - algae culture - shellfish culture - shellfish fisheries - spain
Zeeuwse aquacultuurondernemers zijn in januari 2013 vier dagen naar de regio Cadiz en Huelva in Spanje afgereisd om kennis te maken met de aquacultuuractiviteiten en te leren van de ervaringen daar. Deze studiereis is georganiseerd in het kader van het inmiddels afgeronde RAAK Internationaal project 'Het zoute goud', waarvan HZ University of Applied Sciences penvoerder was. De studiereis naar Spanje vormde samen met een slotsymposium de afsluiting van dit project.
Comment on "Invasive Harlequin Ladybird Carries Biological Weapons Against Native Competitors"
Jong, P.W. de; Lenteren, J.C. van; Raak-van den Berg, C.L. - \ 2013
Science 341 (2013)6152. - ISSN 0036-8075
intraguild predation - harmonia-axyridis - coccinellidae - coleoptera
We comment on the implications that Vilcinskas et al. (Reports, 17 May 2013, p. 862) attach to the finding that the exotic, invasive ladybird Harmonia axyridis carries microsporidia to which this species is insensitive but that is lethal to species that are native to the invaded areas. The authors suggest that these microsporidia might serve as “biological weapons” against the native competitors, but we cast doubt on the importance of this suggestion in the field.
Diapause and post-diapause quiescence demonstrated in overwintering Harmonia axyeidis (Coleoptera: Coccinellidae) in northwestern Europe
Raak-van den Berg, C.L. ; Jong, P.W. de; Hemerik, L. ; Lenteren, J.C. van - \ 2013
European Journal of Entomology 110 (2013)4. - ISSN 1210-5759 - p. 585 - 591.
lady beetle - photoperiodic response - winter survival - septempunctata - reproduction - temperature - netherlands - invasion - behavior - spread
The Asian ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is regarded as an invasive species in many parts of the world. In a previous study we hypothesised that H. axyridis enters diapause at the end of October and then shifts to a quiescent state in December in northwestern Europe. In the present study we test this idea of a short, early period of diapause by sampling beetles from their hibernation sites immediately after their migratory flights in October, subsequently keeping them in outdoor cages, and then, after certain time-intervals, measuring the pre-oviposition time under optimal egg-laying laboratory conditions at 25 degrees C. We did this at both short (12L) and long (16L) photoperiods, since a photoperiodic response is an indicator of true diapause, rather than quiescence. A significant, albeit small, difference in pre-oviposition period between the two photoperiods, which disappears in December, corroborates our earlier hypothesis that the ladybirds are in a state of diapause until mid-December. Compared with that of native ladybirds the diapause of H. axyridis generally is relatively short and weak; moreover, it appears to have become shorter over the last decade. This flexibility in diapausing behaviour may be an important factor that contributes to the invasive success of H. axyridis.
Onderzoek naar alternatieven voor het gebruik van formaline in de bollenteelt : alternatieven voor formaline in de voorweek- en warmwater-behandeling en vervangen van formaline tijdens het ontsmetting via dompelen kort voor planten
Dam, M.F.N. van; Boer, M. de; Lans, A.M. van der; Breeuwsma, S.J. - \ 2013
Lisse : Praktijkonderzoek Plant & Omgeving B.V. - 36
bloembollen - bacterieziekten - schimmelziekten - heetwaterbehandeling - formaldehyde - ontsmettingsmiddelen - desinfectie - ziektepreventie - alternatieve methoden - tests - landbouwkundig onderzoek - ornamental bulbs - bacterial diseases - fungal diseases - hot water treatment - disinfectants - disinfection - disease prevention - alternative methods - agricultural research
Zeeuwse aquacultuurondernemers zijn in januari 2013 vier dagen naar de regio Cadiz en Huelva in Spanje afgereisd om kennis te maken met de aquacultuuractiviteiten en te leren van de ervaringen daar. Deze studiereis is georganiseerd in het kader van het inmiddels afgeronde RAAK Internationaal project 'Het zoute goud', waarvan HZ University of Applied Sciences penvoerder was. De studiereis naar Spanje vormde samen met een slotsymposium de afsluiting van dit project.
Effect van ULO en DCS bewaarcondities en Smartfresh TM op de vruchtkwaliteit van Elstar in de keten en in een ketensimulatie
Schoorl, F.W. - \ 2013
Randwijk : Praktijkonderzoek Plant en Omgeving, Bloembollen, Boomkwekerij & Fruit - 17
appels - voedselkwaliteit - gasbewaring - voedselketens - systemen na de oogst - simulatie - technieken - monitoring - vergelijkend onderzoek - apples - food quality - controlled atmosphere storage - food chains - postharvest systems - simulation - techniques - comparative research
Elstar altijd Raak is een initiatief om de kwaliteit van Elstar aan het eind van de keten te verbeteren en daarmee teleurstellingen bij de consument zoveel mogelijk te voorkomen. Een consistent hogere produkt kwaliteit is nodig om de positie van Elstar te borgen. In de hier beschreven test is gekeken naar de kwaliteitsontwikkeling van verschillende monsters die een praktijkketen hebben doorlopen en monsters die in een gesimuleerde keten hebben gestaan.
Intraguild predation behaviour of ladybirds in semi-field experiments explains invasion success of Harmonia axyridis
Raak-van den Berg, C.L. ; Lange, H.J. de; Lenteren, J.C. van - \ 2012
PLoS ONE 7 (2012)7. - ISSN 1932-6203
coccinella-septempunctata l - aphidophagous ladybirds - adalia-bipunctata - searching behavior - larval tracks - coleoptera - cannibalism - beetle - prey - ecology
Harmonia axyridis has been introduced as a biological control agent in Europe and the USA. Since its introduction, it has established and spread, and it is now regarded as an invasive alien species. It has been suggested that intraguild predation is especially important for the invasion success of H. axyridis. The aim of this study was to compare the intraguild predation behaviour of three ladybird species (Coccinella septempunctata, Adalia bipunctata, and H. axyridis). Predation behaviour was investigated in semi-field experiments on small lime trees (Tilia platyphyllos). Two fourth-instar larvae placed on a tree rarely made contact during 3-hour observations. When placed together on a single leaf in 23%–43% of the observations at least one contact was made. Of those contacts 0%–27% resulted in an attack. Harmonia axyridis attacked mostly heterospecifics, while A. bipunctata and C. septempunctata attacked heterospecifics as often as conspecifics. In comparison with A. bipunctata and C. septempunctata, H. axyridis was the most successful intraguild predator as it won 86% and 44% of heterospecific battles against A. bipunctata and C. septempunctata respectively, whilst A. bipunctata won none of the heterospecific battles and C. septempunctata won only the heterospecific battles against A. bipunctata. Coccinella septempunctata dropped from a leaf earlier and more often than the other two species but was in some cases able to return to the tree, especially under cloudy conditions. The frequency with which a species dropped did not depend on the species the larva was paired with. The results of these semi-field experiments confirm that H. axyridis is a strong intraguild predator as a consequence of its aggressiveness and good defence against predation from heterospecific species. The fact that H. axyridis is such a strong intraguild predator helps to explain its successful establishment as invasive alien species in Europe and the USA.
Control of Dieback, Caused by Eutypa lata, in Red Currant (Ribes rubrum) and Gooseberry (Ribes uva-crispa) in the Netherlands
Wenneker, M. ; Steeg, P.A.H. van der; Vink, P. ; Brouwershaven, I.R. van; Raak, M. van - \ 2012
In: Proceedings of the Tenth International Rubus and Ribes Symposium. - I.S.H.S. - ISBN 9789066052086 - p. 225 - 230.
Over decades, growers in the Netherlands have problems with a disease that causes dying branches and stem cankers in red currant. For many years it was assumed that this disease was related to fungi such as Nectria cinnabarina, Phomopsis spp. and the insect Synanthedon tipuliformis. However, recently it was found by Applied Plant Research and the Plant Protection Service that the causal organism is the fungus Eutypa lata. The disease is considered of major economic importance, especially as red currant growing is rapidly expanding in the Netherlands. E. lata was identified with three detection methods (visual, plating and DNA). Symptoms of E. lata do not usually appear until currant plants are at least three to four years old. These cankers are always associated with old pruning wounds. Eventually, the entire branch is killed. High disease incidences and annual losses of 10% to 30% of the productive branches are reported. In some cases entire fields have to be replanted. E. lata is well known as one of the most destructive diseases of grapevines (Vitis vinifera). The importance of this disease in currant growing was not known. Research is focusing on the evaluation of control measures; e.g. chemical and biological control treatment of pruning wounds, and disease management such as sanitation practices. Also, the epidemiology of E. lata is studied. High densities of ascospores of E. lata were found in a spore trap placed in a red currant field in the Netherlands. In the subsequent field survey fruiting structures (stromata) and ascospores were found on dead infected red currant wood.
Winter survival of Harmonia axyridis in The Netherlands
Raak-van den Berg, C.L. ; Stam, J.M. ; Jong, P.W. de; Hemerik, L. ; Lenteren, J.C. van - \ 2012
Biological Control 60 (2012)1. - ISSN 1049-9644 - p. 68 - 76.
asian lady beetle - septempunctata col.-coccinellidae - environmental risk-assessment - biological-control agents - adalia-bipunctata l - coleoptera-coccinellidae - pallas coleoptera - intraguild predation - united-states - overwintering survival
Since the establishment of Harmonia axyridis in Europe, populations of native ladybirds have decreased. Overwintering survival is one of the aspects of the biology of H. axyridis that may contribute to its firm establishment in and invasion of a new area. In this study winter survival of five wild H. axyridis populations was assessed under natural and semi-natural conditions, with a focus on the potential influence of location and orientation on winter survival. Overwintering survival of H. axyridis in the Netherlands is high: 70.8–88.2%. When overwintering at one central site, populations sampled at five locations showed statistically significant different mortality rates. Furthermore, winter survival of H. axyridis at the sample sites was higher when beetles were hibernating at the southwestern sides of buildings, where most aggregations of ladybirds were found. Survival was higher at sheltered sites compared to exposed sites. Harmonia axyridis has a comparable or higher overwintering survival than most common native ladybird species. A high overwintering survival results in a large post-hibernation population in spring, leading to a rapid population build-up. Thus, the high winter survival probably contributes to the success of the exotic H. axyridis
Mode of overwintering of invasive Harmonia axyridis in the Netherlands
Raak-van den Berg, C.L. ; Hemerik, L. ; Jong, P.W. de; Lenteren, J.C. van - \ 2012
BioControl 57 (2012)1. - ISSN 1386-6141 - p. 71 - 84.
coccinella-septempunctata coleoptera - temperature-dependent development - hippodamia-convergens coleoptera - adalia-bipunctata coleoptera - lady beetle coleoptera - thermal requirements - pallas coleoptera - life-history - photoperiodic response - reproductive di
After establishment of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Europe, population densities of native ladybird species have decreased. The post-hibernation onset of female reproduction, a key characteristic influencing population dynamics and competition with related species, was studied. Hibernating individuals were collected and transferred to outdoor cages to continue overwintering. Every two weeks a sample of individuals was transferred to long-day, warm conditions. Intensity of dormancy was studied by determining the pre-oviposition period and ovarian development. Pre-oviposition periods were short throughout our observations, indicating that Harmonia axyridis was not in diapause but in a quiescent state. H. axyridis becomes active rapidly when temperature rises in spring but is not active earlier in the year than native species. Neither the mode of overwintering, nor the onset of spring activity can explain the invasion success of H. axyridis
The Amsterdam Declaration on Fungal Nomenclature
Hawksworth, D.L. ; Crous, P.W. ; Redhead, S.A. ; Reynolds, D.R. ; Samson, R.A. ; Seifert, K.A. ; Taylor, J.W. ; Wingfield, M.J. ; Abaci, Ö. ; Aime, C. ; Asan, A. ; Bai, F.Y. ; Beer, W. de; Begerow, D. ; Berikten, D. ; Boekhout, T. ; Buchanan, P.K. ; Burgess, T. ; Buzina, W. ; Cai, L. ; Cannon, P.F. ; Crane, J.L. ; Damm, U. ; Daniel, H.M. ; Diepeningen, A.D. van; Druzhinina, I. ; Dyer, P.S. ; Eberhardt, U. ; Fell, J.W. ; Frisvad, J.C. ; Geiser, D.M. ; Geml, J. ; Glienke, C. ; Gräfenhan, T. ; Groenewald, J.Z. ; Groenewald, M. ; Gruyter, J. de; Guého-Kellemann, E. ; Guo, L.D. ; Hibbett, D.S. ; Hong, S.B. ; Hoog, G.S. de; Houbraken, J. ; Huhndorf, S.M. ; Hyde, K.D. ; Ismail, A. ; Johnston, P.R. ; Kadaifciler, D.G. ; Kirk, P.M. ; Köljalg, U. ; Kurtzman, C.P. ; Lagneau, P.E. ; Lévesque, C.A. ; Liu, X. ; Lombard, L. ; Meyer, W. ; Miller, A. ; Minter, D.W. ; Najafzadeh, M.J. ; Norvell, L. ; Ozerskaya, S.M. ; Öziç, R. ; Pennycook, S.R. ; Peterson, S.W. ; Pettersson, O.V. ; Quaedvlieg, W. ; Robert, V.A. ; Ruibal, C. ; Schnürer, J. ; Schroers, H.J. ; Shivas, R. ; Slippers, B. ; Spierenburg, H. ; Takashima, M. ; Taskin, E. ; Thines, M. ; Thrane, U. ; Uztan, A.H. ; Raak, M. van; Varga, J. ; Vasco, A. ; Verkley, G. ; Videira, S.I.R. ; Vries, R.P. de; Weir, B.S. ; Yilmaz, N. ; Yurkov, A. ; Zhang, N. - \ 2011
IMA fungus 2 (2011)1. - ISSN 2210-6340 - p. 105 - 112.
The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19-20 April 2011 under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). The purpose of the symposium was to address the issue of whether or how the current system of naming pleomorphic fungi should be maintained or changed now that molecular data are routinely available. The issue is urgent as mycologists currently follow different practices, and no consensus was achieved by a Special Committee appointed in 2005 by the International Botanical Congress to advise on the problem. The Declaration recognizes the need for an orderly transitition to a single-name nomenclatural system for all fungi, and to provide mechanisms to protect names that otherwise then become endangered. That is, meaning that priority should be given to the first described name, except where that is a younger name in general use when the first author to select a name of a pleomorphic monophyletic genus is to be followed, and suggests controversial cases are referred to a body, such as the ICTF, which will report to the Committee for Fungi. If appropriate, the ICTF could be mandated to promote the implementation of the Declaration. In addition, but not forming part of the Declaration, are reports of discussions held during the symposium on the governance of the nomenclature offungi, and the naming of fungi known only from an environmental nucleic acid sequence in particular. Possible amendments to the Draft BioCode (2011) to allow for the needs of mycologists are suggested for further consideration, and a possible example of how a fungus only known from the environment might be described is presented.
Control of dieback, caused by Eutypa lata, in red currant (Ribes rubrum) and gooseberry (Ribes uva-crispa) in the Netherlands
Wenneker, M. ; Steeg, P.A.H. van der; Vink, P. ; Brouwershaven, I.R. van; Raak, M. van - \ 2011
In: 10th International Rubus & Ribes Symposium, International Society for Horticultural Science, Zlatibor, Serbia, June 22-26, 2011. - - p. 63 - 63.
Wenneker, M., Vink, P., Steeg, van der P., Brouwershaven, van I., Raak, van M., 2011. Control of dieback, caused by Eutypa lata, in red currant (Ribes rubrum) and gooseberry (Ribes uva-crispa) in the Netherlands. In: book of abstracts (p. 63) – 10th International Rubus & Ribes Symposium, International Society for Horticultural Science, Zlatibor, Serbia, June 22-26, 2011. (oral presentation).
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