Plant responses to multiple herbivory : phenotypic changes and their ecological consequences
Li, Yehua - \ 2016
Wageningen University. Promotor(en): Marcel Dicke, co-promotor(en): Rieta Gols. - Wageningen : Wageningen University - ISBN 9789462578043 - 165
brassica oleracea - brevicoryne brassicae - aphidoidea - caterpillars - insect pests - pest resistance - defence mechanisms - phenotypes - insect plant relations - parasitoids - natural enemies - herbivore induced plant volatiles - plant-herbivore interactions - genetic variation - brassica oleracea - brevicoryne brassicae - aphidoidea - rupsen - insectenplagen - plaagresistentie - verdedigingsmechanismen - fenotypen - insect-plant relaties - parasitoïden - natuurlijke vijanden - herbivoor-geinduceerde plantengeuren - plant-herbivoor relaties - genetische variatie
This thesis explores whether aphid-infestation interferes with the plant response to chewing herbivores and whether this impacts performance and behaviour of individual chewing insect herbivores and their natural enemies, as well as the entire insect community. I investigated this using three wild cabbage populations (Brassica oleracea) that are known to differ in inducible secondary chemistry, to reveal whether patterns were consistent.
A literature review on recent developments in the field of plant interactions with multiple herbivores (Chapter 2) addressed how plant traits mediate interactions with various species of the associated insect community and their dynamics. In addition, the mechanisms underlying phenotypic changes in response to different herbivores were discussed from the expression of defence-related genes, phytohormones and secondary metabolites in plants to their effects on the performance and behaviour of individual insects as well as the entire insect community. In Chapter 3, I investigated the effects of early-season infestation by the aphid Brevicoryne brassicae on the composition and dynamics of the entire insect community throughout the season in a garden experiment replicated in two consecutive years. Aphid infestation in the early season only affected a subset of the community, i.e. the natural enemies of aphids, but not the chewing herbivores and their natural enemies. Moreover, the effects were only significant in the first half (June & July), but waned in the second half of the season (August & September). The effect of aphid infestation on the community of natural enemies also varied among the cabbage populations. Chapter 4 investigated the effects of aphid infestation on plant direct defences against chewing herbivores in laboratory experiments by comparing the performance of chewing herbivores and their parasitoids on aphid-infested and aphid-free plants. The performance of the specialist herbivore Plutella xylostella and its parasitoid Diadegma semiclausum was better on plants infested with aphids than on aphid-free plants, whereas the performance of the generalist herbivore Mamestra brassicae and its parasitoid Microplitis mediator was not affected by aphid infestation. These results suggest that aphid induced changes in plant traits may differentially affect the performance of leaf-chewing herbivore species attacking the same host plant, and also varied among the cabbage populations. Chapter 5 examined the effects of B. brassicae aphid infestation on plant indirect defences against chewing herbivores. In a two-choice olfactometer bioassay, preference behaviour for volatiles emitted by plants infested with hosts alone and those emitted by plants infested with aphids and hosts was compared for D. semiclausum and M mediator, larval endoparasitoids of caterpillars of P. xylostella and M. brassicae, respectively. In addition, the headspace volatiles emitted by host-infested and dually-infested plants were collected and analyzed. Co-infestation with aphids differentially affected volatile-mediated foraging behaviour of the two parasitoid species in an infestation period-dependent manner. Diadegma semiclausum preferred dually infested plants over host-infested plants when aphids infested the plants for a short time period, i.e. 7 days, but the volatile preference of D. semiclausum was reversed when aphid infestation was extended to 14 days. In contrast, M. mediator consistently preferred volatiles emitted by the dually-infested plants over those emitted by host-infested plants. The patterns of preference behaviour of the two wasp species were consistent across the three cabbage populations. Interestingly, the emission rate of most volatile compounds was reduced in plants dually-infested with caterpillars and aphids compared to singly-infested with caterpillars. This study showed that aphid infestation increased plant indirect defences against caterpillars, but depended on the aphid infestation period and specific caterpillar-parasitoid association. We hypothesized a negative interference of aphid infestation on plant defences against chewing herbivores based on previously reported SA-JA antagonism. In Chapter 6, we assessed the activation of SA and JA signaling pathways in plants infested by both aphids (B. brassicae) and various caterpillar species (P. xylostella, M. brassicae and Pieris brassicae) in different time sequences by quantifying transcription levels of the SA- and JA-responsive marker genes, PR-1 and LOX respectively. The results did not provide support for SA-JA antagonism. Compared to single infestation with each of the herbivore species, dual infestation with aphid and caterpillars had no interactive effects on the transcription levels of the SA- and JA-responsive maker genes, regardless of the temporal sequence of aphid and caterpillar attack, or the identity of the attacking caterpillar species.
The findings of this thesis contribute to our understanding of plant responses to herbivory by insect species belonging to different feeding guilds and their ecological effects on other associated community members. Aphid infestation may interfere with plant direct and indirect defences against leaf-chewing herbivores at the individual species level, but the effects are species-specific and also depend on the infestation period of aphids. Early-season aphid infestation may further affect the composition of the insect community, but the effect is smaller influencing only a subset of the community compared to early infestation by chewing herbivores. The molecular mechanism underlying plant responses to both phloem-feeding and leaf-chewing herbivores are complex and require the investigation of a range of genes involved in JA- and SA-mediated defence signal transduction. Plant interact with multiple herbivores at different levels of biological organization ranging from the subcellular level to the individual and the community level, and an integrated multidisciplinary approach is required to investigate plant-insect interactions.
Isoprene emission by poplar is not important for the feeding behaviour of poplar leaf beetles
Müller, A. ; Kaling, M. ; Faubert, P. ; Gort, G. ; Smid, H.M. ; Loon, J.J.A. van; Dicke, M. ; Kanawati, B. ; Schmitt-Kopplin, P. ; Polle, A. ; Schnitzler, J.P. ; Rosenkranz, M. - \ 2015
BMC Plant Biology 15 (2015)1. - ISSN 1471-2229 - 16 p.
organic-compound emissions - chrysomela-populi - phratora-vitellinae - plant interactions - emitting poplars - volatiles - biosynthesis - caterpillars - performance - trichocarpa
Background Chrysomela populi (poplar leaf beetle) is a common herbivore in poplar plantations whose infestation causes major economic losses. Because plant volatiles act as infochemicals, we tested whether isoprene, the main volatile organic compound (VOC) produced by poplars (Populus x canescens), affects the performance of C. populi employing isoprene emitting (IE) and transgenic isoprene non-emitting (NE) plants. Our hypothesis was that isoprene is sensed and affects beetle orientation or that the lack of isoprene affects plant VOC profiles and metabolome with consequences for C. populi feeding. Results Electroantennographic analysis revealed that C. populi can detect higher terpenes, but not isoprene. In accordance to the inability to detect isoprene, C. populi showed no clear preference for IE or NE poplar genotypes in the choice experiments, however, the beetles consumed a little bit less leaf mass and laid fewer eggs on NE poplar trees in field experiments. Slight differences in the profiles of volatile terpenoids between IE and NE genotypes were detected by gas chromatography - mass spectrometry. Non-targeted metabolomics analysis by Fourier Transform Ion Cyclotron Resonance Mass Spectrometer revealed genotype-, time- and herbivore feeding-dependent metabolic changes both in the infested and adjacent undamaged leaves under field conditions. Conclusions We show for the first time that C. populi is unable to sense isoprene. The detected minor differences in insect feeding in choice experiments and field bioassays may be related to the revealed changes in leaf volatile emission and metabolite composition between the IE and NE poplars. Overall our results indicate that lacking isoprene emission is of minor importance for C. populi herbivory under natural conditions, and that the lack of isoprene is not expected to change the economic losses in poplar plantations caused by C. populi infestation.
Hoe zorgen zombierupsen voor een beter milieu?
Vet, L.E.M. - \ 2015
Universiteit van Nederland
biodiversiteit - ecosystemen - sluipwespen - rupsen - plagenbestrijding - insectenplagen - organismen ingezet bij biologische bestrijding - milieubeheersing - gewasbescherming - verdedigingsmechanismen - biodiversity - ecosystems - parasitoid wasps - caterpillars - pest control - insect pests - biological control agents - environmental control - plant protection - defence mechanisms
Filmpje van de Universiteit van Nederland: Hoe zorgen zombierupsen voor een beter milieu? Als je verschillende soorten organismen in een ecosysteem hebt, houden ze elkaar in balans. Daarom is biodiversiteit goed voor het milieu. Dit is ook waarom insectenplagen soms erger kunnen worden door het gebruik van pesticiden. Prof. dr. Louise Vet van Wageningen UR onderzoekt daarom hoe zombierupsen plagen kunnen bestrijden.
Bodembacterie helpt plant tegen rupsenvraat
Sikkema, A. ; Pangesti, N.P.D. - \ 2015
Wageningen : St. voor Duurzame Ontwikkeling
arabidopsis - bodembacteriën - rizosfeerbacteriën - pseudomonas - gewasbescherming - rupsen - plaagresistentie - biologische bestrijding - landbouwkundig onderzoek - arabidopsis - soil bacteria - rhizosphere bacteria - pseudomonas - plant protection - caterpillars - pest resistance - biological control - agricultural research
Bodembacteriën die in het wortelmilieu van planten leven, verminderen de vatbaarheid van planten voor rupsenvraat. Dat blijkt uit onderzoek van Wageningse entomologen. In de modelplant Arabidopsis konden ze aantonen dat rhizobacteriën de plant in verhoogde staat van paraatheid brengen.
Inheritance of electrophysiological responses to leaf saps of host- and nonhost plants in two helicoverpa species and their hybrids
Tang, Q.B. ; Huang, L.Q. ; Wang, C.Z. ; Tang, Q.B.T. ; Zhan, H. ; Loon, J.J.A. van - \ 2014
Archives of Insect Biochemistry and Physiology 86 (2014)1. - ISSN 0739-4462 - p. 19 - 32.
contact chemoreception - gustatory sensitivity - recognition cue - pieris-rapae - bombyx-mori - larvae - lepidoptera - caterpillars - noctuidae - evolution
The polyphagous cotton bollworm Helicoverpa armigera (Hubner) and the oligophagous oriental tobacco budworm Helicoverpa assulta (Guenee) (Lepidoptera: Noctuidae) display contrasting heritable feeding preferences for cotton and pepper leaves. In this study, electrophysiological response patterns to cotton and pepper leaf saps in gustatory sensilla styloconica on the maxillae of these two species, their reciprocal F1 hybrids, and backcrossed lines were investigated using the tip recording technique. The identity of the neurons responding to the two leaf saps has been established using action potential waveform analysis. The two plant leaf saps elicited neural activity in at least six of the eight taste neurons innervating the lateral and medial sensilla styloconica of the parental species and crosses. Discriminant analysis of this multineural input predicted that correct classification occurred in 87 - 92% of the cases. Differences in taste neuron responses between insect lines to the two plant saps were consistent with differences in feeding preference behaviors. Comparisons of taste neuron response patterns of parental species, F1 hybrids and backcrosses indicate that autosomal loci contributed to the difference in gustatory response patterns between the two Helicoverpa species with the H. armigera derived alleles being partly dominant to those carried by H. assulta. These findings contribute to the understanding of gustatory codes for preference and provide insight into taste evolution of lepidopteran insects.
Insect herbivore- associated organisms affect plant responses to herbivory
Zhu, F. ; Poelman, E.H. ; Dicke, M. - \ 2014
New Phytologist 204 (2014)2. - ISSN 0028-646X - p. 315 - 321.
spodoptera-littoralis - mediated interactions - indirect defense - host - virus - symbionts - parasites - caterpillars - arabidopsis - hypothesis
In nature, plants interact with many organisms and need to integrate their responses to these diverse community members. Knowledge on plant-insect relationships has accumulated rapidly during the last decades. Yet most studies on direct or indirect defences of plants against herbivory have treated herbivores as individual stressors. However, herbivores often consist of communities themselves, comprising organisms such as parasites and symbionts, which may have important effects on the herbivore phenotype, and consequently on interactions of the herbivore with its food plant. Here, we review how herbivore-associated organisms affect plant-herbivore interactions. Organisms associated with herbivores can directly affect how a plant interacts with their herbivorous hosts, by interfering with plant signal-transduction pathways, repressing the expression of plant defence-related genes, or altering plant secondary metabolism. In addition, herbivore-associated organisms can also affect plant responses indirectly by their effect on the behaviour and physiology of their herbivore host. The changes in plant phenotype that arise from herbivore-associated organisms may subsequently affect interactions with other community members, thereby impacting community dynamics. Furthermore, herbivore-associated organisms may act as a hidden driving force of plant-herbivore coevolution. Therefore, to understand plant-herbivore interactions it is important to realize that every single herbivorous insect constitutes a community in itself.
Al veel meldingen van nesten eikenprocessierups
Hellingman, S. ; Kuppen, H. ; Vliet, A.J.H. van; Bron, W.A. ; Buijs, J. ; Jelsma, R. ; Jans, H. - \ 2014
quercus - plantenplagen - thaumetopoea processionea - rupsen - brandharen - observatie - verspreiding - gezondheidsgevaren - controle - quercus - plant pests - thaumetopoea processionea - caterpillars - urticating hairs - observation - dispersal - health hazards - control
Van Noord- tot Zuid-Nederland zijn al de eerste nesten van de eikenprocessierups aangetroffen. Nog nooit eerder zijn er in mei al zo veel nesten gezien. Het aantal eikenprocessierupsen lijkt ook hoger te liggen dan in voorgaande jaren.
Climbing the walls : behavioural manipulation of insects by baculoviruses
Houte, S. van - \ 2014
Wageningen University. Promotor(en): Just Vlak; Monique van Oers, co-promotor(en): Vera Ros. - Wageningen : Wageningen University - ISBN 9789461738301 - 228
baculoviridae - insecten - rupsen - lepidoptera - gastheer parasiet relaties - diergedrag - gedragsveranderingen - hyperactiviteit - moleculaire biologie - baculoviridae - insects - caterpillars - lepidoptera - host parasite relationships - animal behaviour - behavioural changes - hyperactivity - molecular biology
Parasites often have severe effects on their hosts by causing developmental and physiological alterations in their hosts. These alterations may contribute to parasite growth, reproduction and survival. For example, host development may be inhibited so that more nutrients become available for the parasite. Parasites can also interfere with host behavior as a strategy to increase parasite survival or transmission. This phenomenon is known as ‘parasitic manipulation’ or ‘behavioural manipulation’. Although many examples of parasitic manipulation are known, the genetic basis underlying such manipulations is largely unexplored. A thorough understanding of how parasites manipulate their hosts’ behavior is therefore lacking, but it can be hypothesized that parasites carry specific genes that induce these behavioural alterations. Such ‘behavioural’ parasite genes likely affect one or more host proteins directly or via the expression of specific target genes in the host, which subsequently leads to altered behaviour. Understanding the details of such interactions between parasite and host is important as parasitic manipulation is thought to be wide spread in nature and to be a strong driver of the co-evolutionary arms race between parasite and host. Furthermore, the strategies employed by parasites to alter behavior likely provide important insights in the molecular mechanism of many behavioural processes. Chapter 2 of this thesis reviews our current understanding of the mechanisms of behavioural manipulation in invertebrates. It discusses known examples of behavioural manipulation and the present knowledge on the mechanistic basis of these manipulations. Furthermore, an overview of host genes and proteins that play a conserved role in behavioural traits in different invertebrate species is given. These genes and proteins are worthwhile to be studied in more detail in the context of parasitic manipulation, as they might be suitable targets for parasites to induce behavioural changes.
This thesis focuses on behavioural manipulation in insect hosts by baculoviruses. Baculoviruses are DNA viruses that infect the larval stages of mainly lepidopteran insects. These viruses alter host behaviour in multiple ways. They induce hyperactivity in the larvae, which likely contributes to virus dispersal over a large area. In addition, baculoviruses alter host climbing behaviour leading to death at elevated positions, a phenomenon known as ‘tree-top disease’ or ‘Wipfelkrankheit’. This latter manipulation is thought to contribute to optimal virus dispersal on plant foliage. In the research described in this thesis baculoviruses and their lepidopteran insect hosts are used as a model system to study molecular mechanisms of behavioural manipulation. In Chapter 3 of this thesis the involvement of the protein tyrosine phosphatase (ptp) gene from the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in the induction of hyperactivity of the beet armyworm Spodoptera exigua was studied. A homolog of this gene in Bombyx mori nucleopolyhedrovirus (BmNPV) was previously shown to be important in hyperactivity in the silkworm B. mori. The results in Chapter 3 showed that the AcMNPV ptp gene induces hyperactive behaviour in S. exigua larvae and that the phosphatase activity of the encoded PTP enzyme is crucial for this behavioural change. Phylogenetic inference revealed that the baculovirus ptp is presumably transferred from a (ancestral) lepidopteran host to a baculovirus. Within the family Baculoviridae, ptp is only present in group I NPVs, which are a group of phylogenetically related baculoviruses. It is hypothesized that ptp-induced hyperactivity is an evolutionarily conserved strategy of group I NPVs to manipulate host behaviour.
To obtain insights into the target proteins of the baculovirus PTP enzyme to achieve hyperactive behaviour in infected caterpillars, a PTP substrate analysis was performed. Chapter 4 describes host and viral proteins that were found to co-purify with AcMNPV PTP. Many of these host proteins are known to be important in signalling pathways and behavioural traits. For one of these proteins, 14-3-3 z, mRNA transcript levels were found to be significantly higher in wild type AcMNPV-infected S. exigua larvae as compared to larvae infected with a mutant virus from which the ptp gene has been deleted (AcMNPV Δptp). The 14-3-3 protein is a known activator of the enzymes tryptophan hydroxylase and tyrosine hydroxylase, which in turn are required for synthesis of the neurotransmitters serotonin and dopamine. These signalling molecules are both important determinants in hyperactive behaviour in various organisms, and are associated with behavioural manipulation in several parasite-host systems. In Chapter 9 a model is proposed of how the putative interaction between baculovirus PTP and host 14-3-3 zmay lead to hyperactive behaviour.
Within the baculoviruses two different genes that encode protein tyrosine phosphatases, ptp and ptp2, are found. While the ptp gene induces hyperactivity (described in Chapter 3), no function has yet been assigned to the ptp2 gene. Chapter 5 describes the functional
characterization of the baculovirus ptp2 gene. PTP2 protein carries a conserved consensus sequence that is characteristic for mitogen-activated protein kinase (MAPK) phosphatases. SeMNPV ptp2 induced a mild apoptosis and caspase activation in insect cells upon transient expression, which may be related to its putative function as MAPK phosphatase. Several host proteins that co-purified with SeMNPV PTP2 have known functions in apoptosis and/or MAPK signalling, rendering them promising candidate proteins to be involved in SeMNPV PTP2-induced apoptosis and possibly MAPK signalling. Whether PTP2 also has any behavioural effect is unknown, but the data from this chapter indicate that PTP2 likely has a cellular function during virus infection.
Baculoviruses are known to alter host climbing behaviour, commonly leading to death at elevated positions (tree-top disease). In Chapter 6 the hypothesis was tested that baculovirus-induced hyperactive behaviour and tree-top disease are induced by a single baculovirus gene. To this aim the effect of the hyperactivity-inducing ptp gene (Chapter 3) on tree-top disease was investigated. The results demonstrated that AcMNPV ptp, known to cause hyperactive behaviour in S. exigua, is not involved in tree-top disease in this host. This indicates that hyperactivity and tree-top disease induced by baculoviruses are governed by independent mechanisms. Furthermore, a moulting-dependent effect on tree-top disease in S. exigua was found, which may relate to physiological and/or ecological differences between moulted and unmoulted larvae. In the next chapter (Chapter 7) the effect of AcMNPV infection on tree-top disease was investigated for two different host species, Trichoplusia ni and S. exigua. Data show that in T. ni larvae AcMNPV induces tree-top disease, causing death at elevated positions. In contrast, in S. exigua a moulting-dependent effect on the height at death was observed, as was also described in Chapter 6. Furthermore, in this chapter the role of the AcMNPV egt gene, encoding ecdysteroid UDP glucosyl transferase, on tree-top disease in T. ni and S. exigua larvae was analysed. A homolog of this gene causes tree-top disease in Lymantria dispar larvae infected with L. dispar (Ld) MNPV. The results (Chapter 7) show that AcMNPV egt does not play a role in the observed death at elevated positions in the two host systems studied. This indicates that the role of egt in tree-top disease may not be conserved among members of the family Baculoviridae.
In addition to the mechanisms employed by the generalist baculovirus AcMNPV to alter climbing behaviour, the effect of the specialist baculovirus S. exigua (Se) MNPV on tree-top disease in its only known host S. exigua was studied. In Chapter 8 it is shown that SeMNPV induces tree-top disease by triggering an aberrant response to light, and this positive phototaxis leads to death at elevated positions. A hypothesis is put forward that SeMNPV hijacks a host behavioural pathway that is involved in light perception to induce this positive phototactic response.
Overall, the results of this thesis show that hyperactivity and tree-top disease are induced by baculoviruses through independent mechanisms and that distinct baculovirus species presumably use different genes and proximate mechanisms to induce tree-top disease. While the baculovirus ptp gene induces hyperactivity, possibly by targeting host 14-3-3 z, the baculovirus ptp2 gene may function as a pro-apoptotic gene. The baculovirus egt gene does not have a conserved function in tree-top disease, indicating that other viral genes may underlie this host manipulative strategy. This thesis also demonstrates that tree-top disease in SeMNPV-infected caterpillars is the result of a strong attraction to light.
Parasitic manipulation is a fascinating biological phenomenon that can provide crucial information on how behavioural traits are controlled at the molecular level. The research described in this thesis provides several new insights in the mechanisms by which parasites manipulate the behaviour of their hosts.
Paringsverstoring: een innovatieve oplossing voor rupsenproblemen in de Nederlandse kassen : eindraportage
Griepink, F.C. ; Hora, K. ; Kogel, W.J. de - \ 2013
Wageningen : Plant Research International - 36
glastuinbouw - plantenplagen - chrysodeixis chalcites - rupsen - paringsverstoorders - insectenbestrijding - tests - vruchtgroenten - feromoonvallen - schade - greenhouse horticulture - plant pests - chrysodeixis chalcites - caterpillars - mating disrupters - insect control - tests - fruit vegetables - pheromone traps - damage
In de periode 2008-2012 is een paringsverstoringsmethode tegen Turkse mot Chrysodeixis chalcites getest. Er is gekozen voor Turkse mot omdat dit insect snel veel schade kan aanbrengen in de tomaten- en paprikateelt. Ook is in het verleden door PRI in samenwerking met TNO aangetoond dat paringsverstoring tegen Turkse mot voldoende werkt. De destijds gebruikte feromoonverdamper bleek echter onpraktisch en is in dit onderzoek vervangen door een alternatieve verdamper. De in dit onderzoek ontwikkelde verdamper is op 5 locaties getest in een dichtheid van 500 dispensers per hectare. In feromoonvallen in de behandelde percelen werd geen Turkse mot meer gevangen in tegenstelling tot de niet met feromoon behandelde percelen. Echter in het gewas werden nog steeds rupsjes en dus schade gevonden. De gevonden schade wisselde van bedrijf tot bedrijf. De uiteindelijke conclusie is dat deze methode nog onvoldoende robuust is voor commerciële implementatie
Drie mogelijke sluipwespen tegen Turkse mot in paprika (interview met Amir Grosman)
Arkesteijn, M. ; Grosman, A.H. - \ 2013
Onder Glas 10 (2013)12. - p. 32 - 33.
glastuinbouw - groenten - capsicum - paprika's - organismen ingezet bij biologische bestrijding - chrysodeixis chalcites - sluipwespen - rupsen - landbouwkundig onderzoek - greenhouse horticulture - vegetables - capsicum - sweet peppers - biological control agents - chrysodeixis chalcites - parasitoid wasps - caterpillars - agricultural research
Het onderzoek naar biologische bestrijders van de Turkse mot is zo goed als afgerond. Amir Grosman, onderzoeker gewasbescherming bij Wageningen UR Glastuinbouw, heeft na drie jaar onderzoek drie kandidaten: een ei-parasiet die sinds kort op de markt is en twee rupsparasieten.
Plants under multiple herbivory: consequences for parasitoid search behaviour and foraging efficiency
Bukovinszky, T. ; Poelman, E.H. ; Kamp, A. ; Hemerik, L. ; Prekatsakis, G. ; Dicke, M. - \ 2012
Animal Behaviour 83 (2012)2. - ISSN 0003-3472 - p. 501 - 509.
cotesia-rubecula - induced responses - interaction webs - natural enemies - c-rubecula - communities - heterogeneity - hymenoptera - braconidae - caterpillars
In the field, plants are attacked by several herbivore species both simultaneously and in isolation. Spatial variation in damage to plants by different herbivores may affect the search behaviour of parasitoid wasps, but the consequences of this variation for host–parasitoid interactions are still little understood. We examined the effects of multiple herbivory on the search behaviour of the parasitoid Cotesia glomerata. Reduced parasitism was found in a field tent experiment, when both the host small cabbage white, Pieris rapae, and the nonhost cabbage moth, Mamestra brassicae, were present on Brassica oleracea plants. When hosts and nonhosts occurred on the same or neighbouring plants, this reduction in parasitism was similar, but the underlying behavioural mechanisms were different. In wind tunnel bioassays, parasitoids were equally attracted towards plants infested by the two herbivore species but were more attracted to plants with both herbivore species than to plants with only one. Differences in arrival tendencies therefore could not explain the reduced parasitism in the tent experiment with mixed infestations. Experiments showed that parasitoids readily left nonhost patches, whereas leaving tendencies from mixed patches of hosts and nonhosts were the same as from pure host patches. Therefore, reduced leaving tendencies and reduced host encounters explained the lower parasitism rate in mixed infestations in the tent experiment. Our results show that the spatial context in which hosts and nonhosts attack plants determines the foraging efficiency of parasitoids, with consequences for host–parasitoid interactions
|Landelijke inventarisatie insectenplagen 2010. Eerste ontdekking Aziatische boktor in Nederland
Moraal, L.G. - \ 2011
Tuin en Landschap 33 (2011)20. - ISSN 0165-3350 - p. 36 - 39.
insectenplagen - insecten - anoplophora glabripennis - rupsen - hemiptera - inventarisaties - nederland - insect pests - insects - caterpillars - inventories - netherlands
De bastaardsatijnrups bezorgde badgasten in de duingebieden veel overlast en stond nooit eerder zo hoog genoteerd in de Insecten Top Tien. Voor het eerst gemeld zijn een Amerikaanse wants, een Zuid-Europese cicade en een gevaarlijke nieuwkomer: de Aziatische boktor in Almere
Experience-based behavioral and chemosensory changes in the generalist insect herbivore Helicoverpa armigera exposed to two deterrent plant chemicals
Zhou, D. ; Loon, J.J.A. van; Wang, C.Z. - \ 2010
Journal of Comparative Physiology A-Sensory Neural and Behavioral Physiology 196 (2010)11. - ISSN 0340-7594 - p. 791 - 799.
pieris-rapae larvae - bitter taste stimuli - host-plant - feeding deterrents - sensitivity changes - h-assulta - caterpillars - responses - diet - consumption
Behavioral and electrophysiological responses of larvae of the polyphagous moth species Helicoverpa armigera to two plant-derived allelochemicals were studied, both in larvae that had been reared on a diet devoid of these compounds and in larvae previously exposed to these compounds. In dual-choice cotton leaf disk and pepper fruit disk arena assays, caterpillars reared on a normal artificial diet were strongly deterred by strychnine and strophanthin- K. However, caterpillars reared on an artificial diet containing strychnine were insensitive to strychnine and strophanthin-K. Similarly, caterpillars reared on an artificial diet containing strophanthin-K were also desensitized to both deterrent chemicals. Electrophysiological tests revealed that the deterrent-sensitive neurons in taste sensilla on the maxillae of caterpillars reared on each deterrent- containing diet displayed reduced sensitivity to the two chemicals compared with the caterpillars reared on normal diets. We conclude that the experience-dependent behavioral plasticity was partly based on the reduced sensitivity of taste receptor neurons and that the desensitization of taste receptor neurons contributed to the crosshabituation to the two chemicals.
|Landelijke inventarisatie insectenplagen 2009: Eiken hebben het zwaar te verduren.
Moraal, L.G. - \ 2010
Tuin en Landschap 32 (2010)18. - ISSN 0165-3350 - p. 36 - 39.
quercus - struiken - insectenplagen - bosschade - webben - thaumetopoea processionea - inventarisaties - nederland - rupsen - shrubs - insect pests - forest damage - webs - inventories - netherlands - caterpillars
Rupsenvraat in eiken springt het meest in het oog bij de landelijke inventarisatie van insectenplagen op bomen en struiken 2009. Nieuwkomer onder de eikvretende rupsensoorten is de najaarsspenner. Het meest gemeld werd de eigekn processierups en die staat dus bovenaan in de Insecten Top Tien.
Geen spinsels van eikenprocessierupsen maar spinselmotten
Hellingman, S. ; Vliet, A.J.H. van - \ 2010
Nature Today 2010 (2010)21-05.
insectenplagen - bomen - bosschade - yponomeuta malinellus - webben - rupsen - insect pests - trees - forest damage - yponomeuta malinellus - webs - caterpillars
Momenteel denken veel mensen dat ze spinsels van de eikenprocessierups zien. De spinsels die rond deze tijd worden aangetroffen zijn echter van de spinselmotten. Die van de eikenprocessierups worden pas later in het jaar gevormd.
Eikenprocessierups doorstaat koude winter goed
Mulder, S. - \ 2010
Nature Today 2010 (2010)19-02-2010.
thaumetopoea processionea - overwintering - bosplagen - kou - plantenplagen - rupsen - thaumetopoea processionea - overwintering - forest pests - cold - plant pests - caterpillars
Eikenprocessierupsen zijn niet gedeerd door de langdurige koude van deze winter. Bij het opensnijden van eipakketjes blijken de rupsjes springlevend naar buiten te komen. Het is nog te vroeg om nu al iets te zeggen over de mogelijke overlast later dit jaar. Dat is afhankelijk van de weersomstandigheden in april, wanneer de rupsen normaalgesproken uit hun ei komen.
Chemosensory basis of behavioural plasticity in response to deterrent plant chemicals in the larva of the Small Cabbage White butterfly Pieris rapae
Zhou, D.S. ; Wang, C.Z. ; Loon, J.J.A. van - \ 2009
Journal of Insect Physiology 55 (2009)9. - ISSN 0022-1910 - p. 788 - 792.
bitter taste stimuli - host recognition cue - feeding deterrents - self-selection - caterpillars - sensitivity - insect - chemoreceptors - diet - rejection
Behavioural and electrophysiological responsiveness to three chemically different secondary plant substances was studied in larvae of Pieris rapae L. (Lepidoptera: Pieridae). Three groups of caterpillars were studied that during their larval development were exposed to different rearing diets: an artificial diet or one of two host-plants, cabbage, Brassica oleracea, or nasturtium, Tropaeolum majus. In dual-choice leaf disc assays, caterpillars reared on cabbage were strongly deterred by the phenolic chlorogenic acid, the flavonol glycoside naringin and the alkaloid strychnine. However, behavioural plasticity was found in caterpillars reared on nasturtium or artificial diet in that these did not discriminate against chlorogenic acid. Caterpillars reared on the artificial diet were also significantly less sensitive to naringin and strychnine in the behavioural assay. Electrophysiological studies of the maxillary sensilla styloconica revealed that the deterrent neuron in the medial sensillum, but not in the lateral sensillum, of cabbage-reared caterpillars was more sensitive than the same neuron type of caterpillars reared on nasturtium or artificial diet. We conclude that (1) the diet-induced behavioural habituation to deterrents can at least partly be explained by chemosensory desensitisation of a generalist type of maxillary deterrent neuron; (2) behavioural cross-habituation to the three structurally diverse deterrent compounds can be traced back to cross-sensitivity for these compounds in the same gustatory neuron
Eikenprocessierups in processie op 12 juni te Ede
Vliet, A.J.H. van - \ 2009
Wageningen : Wageningen UR
thaumetopoea processionea - lepidoptera - insectenplagen - brandharen - rupsen - insect pests - urticating hairs - caterpillars
Video-opname van eikenprocessierupsen (juni 2009) in Ede die in meerdere processies tegelijkertijd de boom in klimmen om te eten
Eikenprocessierups verpoppen begint
Vliet, A.J.H. van - \ 2009
Wageningen : Wageningen UR
thaumetopoea processionea - lepidoptera - nesten - insectenplagen - plagenbestrijding - poppen - rupsen - nests - insect pests - pest control - pupae - caterpillars
Video-opnamen van eikenprocessierupsen (juni 2009) in Ede die zijn begonnen aan de verpopping tot vlinder. De verpopping vindt plaats in het nest
Keizersnee eikenprocessierups oktober 2009
Vliet, A.J.H. van - \ 2009
Wapserveen : Biocontrole
thaumetopoea processionea - ontwikkelingsstadia - levensvatbaarheid - insectenplagen - rupsen - developmental stages - viability - insect pests - caterpillars
Om te bepalen hoe ver de eikenprocessierupsjes in recent gevonden eipakketjes ontwikkeld zijn is op 3 oktober 2009 een 'keizersnede' uitgevoerd. Het blijkt dat de rupsen al volledig levensvatbaar zijn. Dit kan betekenen dat in warme jaren een tweede generatie van de eikenprocessierupsen mogelijk is. Meer informatie over de ontwikkeling van de eikenprocessierups in Nederland is te vinden op www.natuurbericht.nl of op www.natuurkalender.nl