Search

Plant secondary metabolites play an important role in mediating interactions with insect herbivores and their natural enemies. Metabolites stored in plant tissues are usually investigated in relation to herbivore behaviour and performance (direct defence), whereas volatile metabolites are often studied in relation to natural enemy attraction (indirect defence). However, so-called direct and indirect defences may also affect the behaviour and performance of the herbivore's natural enemies and the natural enemy's prey or hosts, respectively. This suggests that the distinction between these defence strategies may not be as black and white as is often portrayed in the literature. The ecological costs associated with direct and indirect chemical defence are often poorly understood. Chemical defence traits are often studied in two-species interactions in highly simplified experiments. However, in nature, plants and insects are often engaged in mutualistic interactions with microbes that may also affect plant secondary chemistry. Moreover, plants are challenged by threats above- and belowground and herbivory may have consequences for plant-insect multitrophic interactions in the alternative compartment mediated by changes in plant secondary chemistry. These additional associations further increase the complexity of interaction networks. Consequently, the effect of a putative defence trait may be under- or overestimated when other interactions are not considered.

Over the past two decades a growing body of empirical research has shown that many ecological processes are mediated by a complex array of indirect interactions occurring between rhizosphere-inhabiting organisms and those found on aboveground plant parts. Aboveground–belowground studies have thus far focused on elucidating processes and underlying mechanisms that mediate the behavior and performance of invertebrates in opposite ecosystem compartments. Less is known about genetic variation in plant traits such as defense as that may be driven by above- and belowground trophic interactions. For instance, although our understanding of genetic variation in aboveground plant traits and its effects on community-level interactions is well developed, little is known about the importance of aboveground–belowground interactions in driving this variation. Plant traits may have evolved in response to selection pressures from above- and below-ground interactions from antagonists and mutualists. Here, we discuss gaps in our understanding of genetic variation in plant-related traits as they relate to aboveground and belowground multitrophic interactions. When metabolic resources are limiting, multiple attacks by antagonists in both domains may lead to trade-offs. In nature, these trade-offs may critically depend upon their effects on plant fitness. Natural enemies of herbivores may also influence selection for different traits via top–down control. At larger scales these interactions may generate evolutionary “hotspots” where the expression of various plant traits is the result of strong reciprocal selection via direct and indirect interactions. The role of abiotic factors in driving genetic variation in plant traits is also discussed.

BACKGROUND: Most insect-resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied. RESULTS: Transgenic FaNES1-expressing plants emitted (E)-nerolidol and larger amounts of (E)-DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid-infested transgenic plants over aphid-infested wild-type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid-infested transgenic or wild-type plants. CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management.

Calophyllum brasiliense, a Neotropical species, hosts seven galling Cecidomyiidae reported only for Brazil. Our hypothesis is the distribution of the galling insects associated with C. brasiliense is similar to that of the host plant. We checked gall occurrence by field sampling and by searching data in literature and herbaria. Current results indicate that the occurrence of galling Cecidomyiidae associated with C. brasiliense extends to 13 Brazilian states, as well as to 11 countries of Neotropical America.

The cabbage aphid Brevicoryne brassicae is a specialist herbivore that sequesters glucosinolates from its host plant as a defense against its predators. It is unknown to what extent parasitoids are affected by this sequestration. We investigated herbivore-mediated effects of glucosinolates on the parasitoid wasp Diaeretiella rapae and the predator Episyrphus balteatus. We reared B. brassicae on three ecotypes of Arabidopsis thaliana that differ in glucosinolate content and on one genetically transformed line with modified concentrations of aliphatic glucosinolates. We tested aphid performance and the performance and behavior of both natural enemies. We correlated this with phloem and aphid glucosinolate concentrations and emission of volatiles. Brevicoryne brassicae performance correlated positively with concentrations of both aliphatic and indole glucosinolates in the phloem. Aphids selectively sequestered glucosinolates. Glucosinolate concentration in B. brassicae correlated negatively with performance of the predator, but positively with performance of the parasitoid, possibly because the aphids with the highest glucosinolate concentrations had a higher body weight. Both natural enemies showed a positive performance-preference correlation. The predator preferred the ecotype with the lowest emission of volatile glucosinolate breakdown products in each test combination, whereas the parasitoid wasp preferred the A. thaliana ecotype with the highest emission of these volatiles. The study shows that there are differential herbivore-mediated effects of glucosinolates on a predator and a parasitoid of a specialist aphid that selectively sequesters glucosinolates from its host plant. Electronic supplementary material The online version of this article (doi:10.1007/s10886-012-0065-2) contains supplementary material, which is available to authorized users.

International audience; Scarcity of essential nutrients has led plants to evolve alternative nutritional strategies, such as myrmecotrophy (ant-waste-derived nutrition) and carnivory (invertebrate predation). The carnivorous plant Nepenthes bicalcarata grows in the Bornean peatswamp forests and is believed to have a mutualistic relationship with its symbiotic ant Camponotus schmitzi. However, the benefits provided by the ant have not been quantified. We tested the hypothesis of a nutritional mutualism, using foliar isotopic and reflectance analyses and by comparing fitness-related traits between ant-inhabited and uninhabited plants. Plants inhabited by C. schmitzi produced more leaves of greater area and nitrogen content than unoccupied plants. The ants were estimated to provide a 200% increase in foliar nitrogen to adult plants. Inhabited plants also produced more and larger pitchers containing higher prey biomass. C. schmitzi-occupied pitchers differed qualitatively in containing C. schmitzi wastes and captured large ants and flying insects. Pitcher abortion rates were lower in inhabited plants partly because of herbivore deterrence as herbivory-aborted buds decreased with ant occupation rate. Lower abortion was also attributed to ant nutritional service. The ants had higher δ15N values than any tested prey, and foliar δ15N increased with ant occupation rate, confirming their predatory behaviour and demonstrating their direct contribution to the plant-recycled N. We estimated that N. bicalcarata derives on average 42% of its foliar N from C. schmitzi wastes, (76% in highly-occupied plants). According to the Structure Independent Pigment Index, plants without C. schmitzi were nutrient stressed compared to both occupied plants, and pitcher-lacking plants. This attests to the physiological cost of pitcher production and poor nutrient assimilation in the absence of the symbiont. Hence C. schmitzi contributes crucially to the nutrition of N. bicalcarata, via protection of assimilatory organs, enhancement of prey capture, and myrmecotrophy. This combination of carnivory and myrmecotrophy represents an outstanding strategy of nutrient sequestration.

Clinodiplosis Kieffer, 1895 (Diptera, Cecidomyiidae) é gênero cosmopolita conhecido por 103 espécies, a maioria micófaga. Com base na literatura e dados da coleção de Cecidomyiidae do Museu Nacional, Rio de Janeiro, a diversidade deste gênero no Brasil é avaliada, e informações sobre as espécies, seus hábitos e galhas são apresentadas. O gênero está representado, no Brasil, por 57 espécies (17 descritas e 40 não determinadas), o que corresponde a cerca de 16% do total de espécies descritas e 74% da fauna Neotropical. A maioria das espécies encontradas no Brasil é indutora de galhas (81%) e, destas, a metade induz galhas foliares. Gema, flor e caule foram outros órgãos vegetais galhados. As espécies estão associadas a trinta famílias botânicas, sendo mais comuns em Asteraceae, Myrtaceae e Verbenaceae. A maior parte foi coletada em Mata Atlântica, principalmente em restinga, e São Paulo suporta o maior número de espécies registradas. Oito registros novos de planta hospedeira são apresentados. Clinodiplosis Kieffer, 1895 (Diptera, Cecidomyiidae) is a cosmopolitan genus known from 103 species, the majority mycophagous. Based on literature and data from the Cecidomyiidae collection of Museu Nacional, Rio de Janeiro, the diversity of Clinodiplosis in Brazil is surveyed and information about the species, their habits and galls are shown. The genus is represented in Brazil by 57 species (17 described and 40 not determined), which means about 16% of the described species total and 74% of the Neotropical fauna. The majority of species found in Brazil are gall inducers (81%) and the half of these induces leaf galls. Bud, flower and stem were other galled plant organs. The species are associated to thirty plant families, being more common on Asteraceae, Myrtaceae and Verbenaceae. Most of them were collected in Atlantic forest, mainly in "restinga", and São Paulo supports the greatest number of recorded species. Eight new records of host plant are presented.

Spintherophyta semiaurata (Klug) is reported for the first time damaging flowers of strawberry (Fragaria x ananassa) in the municipality of São José dos Pinhais, State of Parana, Brazil.

Description of a new African species of Conicobruchus Decelle, 1951 (Coleoptera, Chrysomelidae, Bruchinae). Conicobruchus acerrimus n. sp. is described from Zimbabwe and the eastern part Democratic Republic of the Congo. The species is closely related with C. nodieri (Pic) and C. astragalinae (Delobel & Le Rü), both with larvae known to feed in the seeds of Leguminosae Indigofereae. Nothing is known of the biology of this species., Conicobruchus acerrimus n. sp. est décrit du Zimbabwe et de l'est de la République démocratique du Congo. L'espèce est apparentée à C. nodieri (Pic) et C. astragalinae (Delobel & Le Rü), deux consommateurs de graines de légumineuses Indigofereae au cours de leur stade larvaire. Sa biologie est inconnue., Delobel Alex. Une nouvelle espèce africaine de Conicobruchus Decelle, 1951 (Coleoptera, Chrysomelidae, Bruchinae). In: Bulletin de la Société entomologique de France, volume 116 (2),2011. pp. 155-158.

International audience; 1. Belowground herbivory has recently been shown to disrupt the host location behaviour of aboveground parasitoids and thereby impact plants indirect defences. Reverse interactions, on the other hand, have received little attention so far. 2. Lab and field studies were conducted to examine whether the presence of the leaf herbivore Pieris brassicae Linnaeus on brassicaceous plants influences the response of Trybliographa rapae Westwood, a specialist parasitoid of the root feeder Delia radicum Linnaeus. 3. The present results show that the attraction of the parasitoid towards host-infested plants disappeared when these plants were also infested by P. brassicae. This absence of attraction was observed both when the complete odour blend or only undamaged leaves from damaged plants were offered, emphasising the role of systemically induced volatiles for host location in T. rapae. 4. Furthermore, the field study revealed that parasitism levels dropped from 30% on root-infested plants to 4% on double-infested plants. 5. The present study is the first to confirm that reduced attraction to host-infested plants as a result of simultaneous attack by below- and aboveground herbivores translates into lower levels of parasitism in the field.

Twenty-three species of Lopesia Rübsaamen (Diptera, Cecidomyiidae) are known, all as gall inducers. Most part is Neotropical, also represented in the Nearctic, Afrotropical, and Australasian. The diversity of the genus in Brazil is surveyed based on literature and data from the Cecidomyiidae collection of Museu Nacional, Rio de Janeiro. The genus is represented in Brazil by 23 species (18 described and 5 not determined), which means 78% of the total of the described species and 95% of the Neotropical fauna. These data show that Lopesia is a well represented genus in Brazil. The majority of the species (78%) induces leaf galls, bud and stem are other galled plant organs. The species are associated with ten plant families, being more common on Burseraceae, Clusiaceae, and Fabaceae. Most part was collected in Atlantic Forest, mainly in "restinga" areas, and Rio de Janeiro supports the greatest number of recorded species. The geographic distribution of three species is widened. Vinte e três espécies de Lopesia Rübsaamen (Diptera, Cecidomyiidae) são conhecidas, todas como indutoras de galhas. A maioria das espécies é Neotropical, também com distribuição Neártica, Afrotropical e Australasiana. A diversidade do gênero no Brasil é avaliada com base na literatura e dados da coleção de Cecidomyiidae do Museu Nacional, Rio de Janeiro. O gênero está representado no Brasil por 23 espécies (18 descritas e 5 não determinadas), o que corresponde a 78% do total de espécies descritas e 95% da fauna neotropical fauna. Estes dados mostram que o gênero é representado no Brasil. A maioria das espécies (78%) induz galhas foliares. Gema e caule foram outros órgãos vegetais galhados. As espécies estão associadas a dez famílias botânicas, sendo mais comuns em Burseraceae, Clusiaceae e Fabaceae. A maior parte foi coletada em Mata Atlântica, principalmente em restinga, e o Rio de Janeiro suporta o maior número de espécies registradas. A distribuição geográfica de três espécies é ampliada.

The genome of the pea aphid shows remarkable levels of gene duplication and equally remarkable gene absences that shed light on aspects of aphid biology, most especially its symbiosis with Buchnera., Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems., Author Summary Aphids are common pests of crops and ornamental plants. Facilitated by their ancient association with intracellular symbiotic bacteria that synthesize essential amino acids, aphids feed on phloem (sap). Exploitation of a diversity of long-lived woody and short-lived herbaceous hosts by many aphid species is a result of specializations that allow aphids to discover and exploit suitable host plants. Such specializations include production by a single genotype of multiple alternative phenotypes including asexual, sexual, winged, and unwinged forms. We have generated a draft genome sequence of the pea aphid, an aphid that is a model for the study of symbiosis, development, and host plant specialization. Some of the many highlights of our genome analysis include an expanded total gene set with remarkable levels of gene duplication, as well as aphid-lineage-specific gene losses. We find that the pea aphid genome contains all genes required for epigenetic regulation by methylation, that genes encoding the synthesis of a number of essential amino acids are distributed between the genomes of the pea aphid and its symbiont, Buchnera aphidicola, and that many genes encoding immune system components are absent. These genome data will form the basis for future aphid research and have already underpinned a variety of genome-wide approaches to understanding aphid biology.

Flea beetles are characterized by their tendency to jump. They can also fly. First, the effects of starvation on flight activity in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae) were determined. After starving P. nemorum for five days a greater number of individuals of both sexes flew than when fed continuously for the same period. In addition, the effect of the mating status of females of P. nemorum on their movement was determined. Mated females were more active than virgin females. It is concluded that starvation stimulates the flight activity of both sexes and mating activates the movement of females of P. nemorum.

In the south-west of France the protected butterfly Euphydryas aurinia occurs mainly in two habitat types: humid herbaceous vegetations and dry grasslands, where it is supposed to use Succisa pratensis and Scabiosa columbaria respectively as larval host-plants. Our observations from 2005 to 2009 in the western part of the Gironde department showed the frequent use of another host-plant: Lonicera periclymenum. This part of the Gironde is covered by evenaged maritime pine stands. Larval nests were mainly observed in Molinia caerulea dominated clearcuttings and firebreaks, and at pine stand edges., Dans le Sud-Ouest de la France, Euphydryas aurinia, un papillon de jour protégé, colonise principalement deux types d’habitats : des milieux herbacés humides et des pelouses sèches. Les plantes-hôtes généralement admises pour les chenilles sont respectivement Succisa pratensis pour le premier type d’habitat et Scabiosa columbaria pour le second. Nos observations, réalisées entre 2005 et 2009 dans la partie ouest du département de la Gironde, ont montré l’utilisation fréquente d’une autre plante-hôte : Lonicera periclymenum. Cette partie de la Gironde est principalement occupée par des plantations de pins maritimes et les nids de chenilles ont été observés dans des coupes rases et des pare-feux dominés par la Molinie et en bordure des peuplements de pins.

Trichogramma species (Hymenoptera: Trichogrammatidae) are haplo-diploid egg parasitoids that are frequently used as biological control agents against lepidopteran pests. These wasps display two reproductive modes, including arrhenotoky (bisexuality) and thelytoky (unisexuality). Thelytokous forms are often associated with the presence of endosymbiotic Wolbachia bacteria. The use of thelytokous wasps has long been considered as a way to enhance the efficacy of biological control. The present study investigates the potential of a thelytokous Wolbachia-infected and an arrhenotokous uninfected Trichogramma brassicae Bezdenko strain as inundative biocontrol agents by evaluating their functional response towards different egg densities of the factitious host, the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae). The results revealed a type II functional response for both strains in which parasitism efficiency decreases with host egg density because of an increasing host handling time. A model with an indicator variable was used to compare the parameters of Holling's disc equation in different data sets. It was demonstrated that the two strains did not differ in host attack rate. However, the Wolbachia-infected strain did have an increased host handling time when compared to the bisexual strain. Some applied aspects of the findings are discussed.

Attacks by herbivores elicit changes in the bouquet of volatiles released by plants. These herbivore-induced plant volatiles (HIPVs) have been interpreted as being indirect defenses. However, given that no studies have yet investigated whether HIPVs benefit the fitness of a plant, their defensive function remains to be established. Moreover, herbivores, pathogens, pollinators and competitors also respond to HIPVs and, in addition, neighbouring plants in native populations also emit volatiles that provide a background odour. These considerations enrich the evolutionary context of HIPVs and complicate predictions about their adaptive value. Molecular advances in our understanding of HIPV signaling and biosynthesis is enabling the creation of HIPV-'mute' and possibly HIPV-'deaf' plants. As we discuss here, such plants could be used for unbiased examination of the fitness value of HIPV emissions under natural conditions.

Root-feeding insects can affect the performance of aboveground insect herbivores when they are forced to feed on the same host plant. Here we explored whether the oviposition behaviour of two closely related herbivorous species (cabbage butterflies; Lepidoptera: Pieridae) is influenced by root-feeding insects, when they are given the chance to choose between host plants with and without root herbivores. Considering that egg load is an important physiological factor influencing the foraging behaviour of insects, we also examined whether root-feeding insects differentially influence oviposition preference in butterflies with low and high egg loads. Oviposition preference in both butterfly species with low and high egg loads was monitored using host plants with and without root herbivores. To ascertain the status of butterfly age with low and high egg loads, the oviducts of a separate group of butterflies was dissected to record the number of immature and mature eggs in butterflies of various ages. Pieris brassicae L. butterflies with low egg loads preferred plants without root herbivores over plants with root herbivores, and laid more egg clutches on the leaves of plants that were not attacked by root herbivores. Butterflies with comparatively high egg loads also selected a larger proportion of plants without root herbivores, but laid a similar number of egg clutches on the plant shoots independent of the presence or absence of root herbivores belowground. Independent of the age and egg load, Pieris rapae L. butterflies selected a larger proportion of plants not attacked by root herbivores to lay eggs, but the number of eggs laid was similar in plants with and without root herbivores. This study shows that belowground insects can influence behavioural decisions of aboveground insect herbivores. Interestingly, the strength of these interactions depends on the physiological state of the insects which is probably correlated with their perception of environmental quality.

Plants under herbivore attack are able to initiate indirect defense by synthesizing and releasing complex blends of volatiles that attract natural enemies of the herbivore. However, little is known about how plants respond to infestation by multiple herbivores, particularly if these belong to different feeding guilds. Here, we report the interference by a phloem-feeding insect, the whitefly Bemisia tabaci , with indirect plant defenses induced by spider mites ( Tetranychus urticae ) in Lima bean ( Phaseolus lunatus ) plants. Additional whitefly infestation of spider-mite infested plants resulted in a reduced attraction of predatory mites ( Phytoseiulus persimilis ) compared to attraction to plants infested by spider mites only. This interference is shown to result from the reduction in ( E )-β-ocimene emission from plants infested by both spider mites and whiteflies. When using exogenous salicylic acid (SA) application to mimic B. tabaci infestation, we observed similar results in behavioral and chemical analyses. Phytohormone and gene-expression analyses revealed that B. tabaci infestation, as well as SA application, inhibited spider mite-induced jasmonic acid (JA) production and reduced the expression of two JA-regulated genes, one of which encodes for the P. lunatus enzyme β-ocimene synthase that catalyzes the synthesis of ( E )-β-ocimene. Remarkably, B. tabaci infestation concurrently inhibited SA production induced by spider mites. We therefore conclude that in dual-infested Lima bean plants the suppression of the JA signaling pathway by whitefly feeding is not due to enhanced SA levels.

The post-embryonic development of Caligo illioneus (Cramer, 1775) (Lepidoptera, Nymphalidae, Brassolinae) feeding on leaves of Heliconia bihai (L.) L. (Heliconiaceae), in laboratory. This study involved the following aspects: determination of larval (duration the instars, in days) and pupal stadia; the sex ratio and the viability of the eggs under laboratory conditions. Eggs and larvaes of C. illioneus were collected in leaves of H. wagneriana Petersen and maintained in the laboratory to register the dates of biological events (hatching, ecdysis, death, pupation and emergence of adults), and larvae behavior. The post-embryonic period (in days, average ± standard error) was 54,58 ± 0,44. The larval period had 40,00 ± 0,43 days and this period were represented by five instars: L1= 7,88 ± 0,23; L2= 6,42 ± 0,16; L3= 5,19 ± 0,25; L4= 7,04 ± 0,19 and L5= 13,46 ± 0,28 (the active larval period was 12,46 ± 0,28 followed by an one day prepupal period). The pupal instar was 14,58 ± 0,20 and the inactive period of the post-embryonic development was 15,58 ± 0,20. Were obtained 26 adults (the sex ratio was 0,46), that represented 56,52% of the eggs viability and 76,47% of the neonates. The morphometric analysis indicates that it is possible estimate the larval development phase based on the width of cephalic capsules, considering intervals values (in mm): L1= 1,457―1,605; L2= 1,951―2,272; L3= 3,139―3,488; L4= 4,970―5,600; L5= 7,423―8,557. The biological control agents, that naturally parasitized the imatures (egg and pupae) of C. illioneus were specimens of Conura maculata (Fabricius, 1758) (Hymenoptera: Chalcididae: Chalcidini) pupae parasitoids and a singly puparium (Diptera). For one egg were recorded specimens of Eulophidae (Hymenoptera) egg parasitoids. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Desenvolvimento pós-embrionário de Caligo illioneus (Cramer, 1775) (Lepidoptera, Nymphalidae, Brassolinae) alimentando-se de folhas de Heliconia bihai (L.) L. (Heliconiaceae), em laboratório. Este estudo foi desenvolvido visando os seguintes aspectos: a determinação dos estádios (duração de instares, em dias) dos períodos larval e pupal; a razão sexual e a viabilidade dos ovos, em condições de laboratório. Ovos e larvas de C. illioneus foram coletados em folhas de H. wagneriana Petersen e acompanhados em laboratório para o registro dos eventos biológicos (eclosão, ecdises, mortes, pupação e emergência dos adultos) e observação do com portamento de cinco larvas. O período pós-embrionário teve uma duração (média ± erro-padrão), em dias de 54,58 ± 0,44. O período larval foi de 40,00 ± 0,43 dias, sendo representado por cinco instares: L1= 7,88 ± 0,23; L2= 6,42 ± 0,16; L3= 5,19 ± 0,25; L4= 7,04 ± 0,19 e L5= 13,46 ± 0,28 (sendo o período larval ativo de 12,46 ± 0,28, seguido de apenas um dia de prepupa). O período pupal foi de 14,58 ± 0,20 e o período inativo do desenvolvimento pós-embrionário foi de 15,58 ± 0,20. Ao final do acompanhamento, foram obtidos 26 adultos (razão sexual de 0,46), o que representou uma viabilidade de 56,52% do total de ovos e de 76,47% dos neonatos obtidos. A análise morfométrica demonstrou que a indicação da fase de desenvolvimento larval de C. illioneus pode ser realizada com base na largura das cápsulas cefálicas, considerando os seguintes intervalos (em mm): L1= 1,457―1,605; L2= 1,951―2,272; L3= 3,139―3,488; L4= 4,970―5,600; L5= 7,423―8,557). Os agentes de controle biológico que naturalmente parasitaram os imaturos (ovo e pupa) da espécie C. illioneus foram parasitóides de pupa: Conura maculata (Fabricius, 1758) (Hymenoptera: Chalcididae: Chalcidini) e um único pupário de Diptera. Apenas um ovo estava parasitado por espécimes da família Eulophidae (Hymenoptera).

In the course of a study on Cressa cretica, an endangered plant living in transient salt marshes, we detected a parasitism involving the rare weevi l Sharpia rubida. The consequences fo r the reprodu ction of the plant may be dramatic, since up to about 90% of the flower buds are destroyed. Ovipos ition and larval developm ent of Sharpia rubida occur in the flower buds between the end of July and the end of Aug ust. The fourth-instar larvae pupate in the soil. Adults emerge in September and overwinter in the surrounding vegetation.

Root herbivores and plant mutualists, such as arbuscular mycorrhizal fungi (AMF), have a significant effect on the structure and dynamic of plant communities. Nevertheless, the interactions between the two groups of organisms in natural ecosystems are far from understood. We carried out an inoculation experiment to examine the effect of two root herbivores, Pratylenchus penetrans and P. dunensis (Nematoda), on the composition of the AMF communities associated with two populations of the dune grass Ammophila arenaria. The outcome of the interaction in terms of plant and nematode performance was also analyzed. The total percentage of AMF colonization was not affected by the presence of root-feeders, but they did alter the composition of the AMF communities inside the roots. These changes were dependent on the root-feeder species and the original AMF community: the most severe alterations were observed in the mycorrhizal plants from Wales attacked by P. penetrans. Plant growth was impaired in plants from Wales inoculated with AMF and P. dunensis, which suggests a highly species-specific synergistic interaction with negative consequences for the plant. Root infection by the nematodes was reduced in all mycorrhizal plants when compared to non-mycorrhizal plants. However, a significant reduction of the final number of nematodes was observed only in the mycorrhizal plants from one population. http://www.sciencedirect.com/science/article/B7GVS-4SSP7BN-3/1/fa6c5c650a18615fab2d9cdc479ebf24

The differences of prevalence among species of micro-fungi that parasitize a same host-plant species ; how to evaluate their statistical significance, using a newly designed test. Beyond simply recording the list of parasitic microfungi that occur within a given region -which is a first necessity -some quantitative aspects regarding the distribution of species may also be of additional interest. Among these aspects, the differences between the occurring frequencies of different species of microfungi that parasitize a same host-plant species feature special interest. The subject, however, raises a specific issue regarding the testing for statistical significance of the differences between the recorded occurrence frequencies, since the common practice, while sampling parasitic micro-fungi, involves the census of fungi occurring on host but almost never the complementary census of the absences of the same fungi. Accordingly, enumerative census are available only and not the corresponding frequencies. As knowing those frequencies is mandatory for common statistical tests to be performed, some special adaptation of those tests has to be considered beforehand. Accordingly, a modified x2 test has then been designed (see the Appendice in English) to assess appropriately the statistical significance of the gaps between the frequencies of occurrence of different species of fungi parasitizing a same host-species. This relevant methodology is then applied to the data collected during a survey of the distributions of Erysiphales, Peronosporales, Ustilaginales and Uredinales in Southern Burgundy (mainly Saône-et-Loire department). The most obvious (statistically significant) differences between the levels of occurrence of different micro-fungi species parasitic on a same given host-plant species are thus disclosed and a particular attention is devoted to the comparison between the respective frequencies of autoecious and heteroecious Rust-species that parasitize a same host-plant species. Autoecious species are generally considered more evolved than heteroecious ones and, accordingly, are logically expected to take benefit from the easier completion of their simpler, one-host life-cycle. Surprisingly, this expected advantage does not reveal statistically significant when occurrence frequencies are compared between heteroecious and autoecious species occurring on a same host, at least on the basis of our recorded data. This trend, however, needs to be substantiate by further investigations based on additionnai similar works in the same and several other regions., Au-delà du simple recensement des espèces de champignons parasites des plantes sauvages, des aspects plus quantitatifs de leurs distributions méritent d'être considérés. Il est en particulier intéressant de mettre en évidence les différences de fréquences d'occurrence entre espèces fongiques parasites d'une même espèce végétale-hôte et de pouvoir s'assurer objectivement de la signification statistique de telles différences. Quelques points méthodologiques préalables à une étude rationnelle de cette question sont abordés avant analyse des résultats obtenus à partir d'un premier échantillonnage de plus de 200 espèces de rouilles, oïdiums, charbons et mildious récoltés sur 286 espèces de plantes-hôtes en Bourgogne méridionale. La signification évolutive qui peut être hypothétiquement attachée aux écarts entre fréquences relatives d'occurrence des rouilles sur une même espèce-hôte est ensuite discutée en liaison avec le caractère hétéroïque ou autoïque des espèces concernées., Béguinot Jean. Différences de fréquences d'occurrence entre espèces de micromycètes parasitant une même espèce de plante-hôte ; procédure d'appréciation statistique. In: Bulletin mensuel de la Société linnéenne de Lyon, 77ᵉ année, n°7-8, Septembre-octobre 2008. pp. 99-112.

Induction of plant defences by early season herbivores can mediate interspecific herbivore competition. We have investigated plant-mediated competition between three herbivorous insects through studies at different levels of biological integration. We have addressed (i) gene expression; (ii) insect behaviour and performance under laboratory conditions; and (iii) population dynamics under field conditions. We studied the expression of genes encoding a trypsin inhibitor and genes that are involved in glucosinolate biosynthesis in response to early season herbivory by Pieris rapae caterpillars in Brassica oleracea plants. Furthermore, we studied the interaction of these transcriptional responses with responses to secondary herbivory by the two specialist herbivores, P. rapae and Plutella xylostella, and the generalist Mamestra brassicae. P. rapae-induced responses strongly interacted with plant responses to secondary herbivory. Sequential feeding by specialist herbivores resulted in enhanced or similar expression levels of defence-related genes compared to primary herbivory by specialists. Secondary herbivory by the generalist M. brassicae resulted in lower gene expression levels than in response to primary herbivory by this generalist. Larval performance of both specialist and generalist herbivores was negatively affected by P. rapae-induced plant responses. However, in the field the specialist P. xylostella was more abundant on P. rapae-induced plants and preferred these plants over undamaged plants in oviposition experiments. In contrast, the generalist M. brassicae was more abundant on control plants and preferred undamaged plants for oviposition. P. rapae did not discriminate between plants damaged by conspecifics or undamaged plants. Our study shows that early season herbivory differentially affects transcriptional responses involved in plant defence to secondary herbivores and their population development dependent upon their degree of host plant specialization.

Root herbivores can indirectly affect aboveground herbivores by altering the food quality of the plant. However, it is largely unknown whether plant genotypes differ in their response to root herbivores, leading to variable defensive phenotypes. In this study, we investigated whether root-feeding insect larvae (Agriotes sp. larvae, wireworms) induce different responses in Plantago lanceolata plants from lines selected for low and high levels of iridoid glycosides (IG). In the absence of wireworms, plants of the “high-IG line” contained approximately twofold higher levels of total IG and threefold higher levels of catalpol (one of the IG) in leaves than plants from the “low-IG line,” whereas both lines had similar levels of IG in roots. In response to wireworms, roots of plants from both lines showed increased concentrations of catalpol. Leaves of “low-IG line” plants increased catalpol concentrations in response to wireworms, whereas catalpol concentrations of leaves of “high-IG line” plants decreased. In contrast, glucose concentrations in roots of “low-IG” plants decreased, while they increased in “high-IG” plants after feeding by wireworms. The leaf volatile profile differed between the lines, but was not affected by root herbivores. In the field, leaf damage by herbivores was higher in wireworm-induced compared to noninduced “low-IG” plants and lower in wireworm-induced compared to noninduced “high-IG” plants, despite induction of catalpol in leaves of the “low-IG” plants and reduction in “high-IG” plants. This pattern might arise if damage is caused mainly by specialist herbivores for which catalpol may act as feeding stimulant rather than as deterrent. The present study documents for the first time that intraspecific variation in plant defense affects the outcome of plant-mediated interactions between root and shoot herbivores.

Lepidopterism by Hylesia nigricans (Berg) moth is recorded for the first time in southern Brazil. Preventive strategies of control are proposed based on information on the biology and ecology of this moth. É registrado pela primeira vez o lepidopterismo provocado pela mariposa Hylesia nigricans (Berg) para o sul do Brasil. São apresentados alguns aspectos da biologia da espécie e relatadas medidas como estratégia preventiva de controle.

Interactions between butterflies and caterpillars in the genus Pieris and plants in the family Brassicaceae are among the best explored in the field of insect-plant biology. However, we report here for the first time that Pieris brassicae, commonly assumed to be a typical folivore, actually prefers to feed on flowers of three Brassica nigra genotypes rather than on their leaves. First- and second-instar caterpillars were observed to feed primarily on leaves, whereas late second and early third instars migrated via the small leaves of the flower branches to the flower buds and flowers. Once flower feeding began, no further leaf feeding was observed. We investigated growth rates of caterpillars having access exclusively to either leaves of flowering plants or flowers. In addition, we analyzed glucosinolate concentrations in leaves and flowers. Late-second- and early-third-instar P. brassicae caterpillars moved upward into the inflorescences of B. nigra and fed on buds and flowers until the end of the final (fifth) instar, after which they entered into the wandering stage, leaving the plant in search of a pupation site. Flower feeding sustained a significantly higher growth rate than leaf feeding. Flowers contained levels of glucosinolates up to five times higher than those of leaves. Five glucosinolates were identified: the aliphatic sinigrin, the aromatic phenylethylglucosinolate, and three indole glucosinolates: glucobrassicin, 4-methoxyglucobrassicin, and 4-hydroxyglucobrassicin. Tissue type and genotype were the most important factors affecting levels of identified glucosinolates. Sinigrin was by far the most abundant compound in all three genotypes. Sinigrin, 4-hydroxyglucobrassicin, and phenylethylglucosinolate were present at significantly higher levels in flowers than in leaves. In response to caterpillar feeding, sinigrin levels in both leaves and flowers were significantly higher than in undamaged plants, whereas 4-hydroxyglucobrassicin leaf levels were lower. Our results show that feeding on flower tissues, containing higher concentrations of glucosinolates, provides P. brassicae with a nutritional benefit in terms of higher growth rate. This preference appears to be in contrast to published negative effects of volatile glucosinolate breakdown products on the closely related Pieris rapae.

Plasmid transfer among isolates of Rhizobium leguminosarum bv. viciae in heavy metal contaminated soils from a long-term experiment in Braunschweig, Germany, was investigated under laboratory conditions. Three replicate samples each of four sterilized soils with total Zn contents of 54, 104, 208 and 340 mg kg −1 were inoculated with an equal number (1×10 5 cells g −1 soil) of seven different, well-characterized isolates of R. leguminosarum bv. viciae . Four of the isolates were from an uncontaminated control plot (total Zn 54 mg kg −1 ) and three were from a metal-contaminated plot (total Zn 340 mg kg −1 ). After 1 year the population size was between 10 6 and 10 7 g −1 soil, and remained at this level in all but the most contaminated soil. In the soil from the most contaminated plot no initial increase in rhizobial numbers was seen, and the population declined after 1 year to −1 soil after 4 years. One isolate originally from uncontaminated soil that had five large plasmids (no. 2-8-27) was the most abundant type re-isolated from all of the soils. Isolates originally from the metal-contaminated soils were only recovered in the most contaminated soil. After 1 year, four isolates with plasmid profiles distinct from those inoculated into the soils were recovered. One isolate in the control soil appeared to have lost a plasmid. Three isolates from heavy metal contaminated soils (one isolate from the soil with total Zn 208 mg kg −1 and two isolates from the soil with total Zn 340 mg kg −1 ) had all acquired one plasmid. Plasmid transfer was confirmed using the distinct ITS–RFLP types of the isolates and DNA hybridization using probes specific to the transferred plasmid. The transconjugant of 2-8-27 which had gained a plasmid was found in one replicate after 2 years of the most contaminated soil but comprised more than 50% of the isolates. A similar type appeared in a separate replicate of the most contaminated soil after 3 years and persisted in both of these soils until the final sampling after 4 years. After 2 years isolates were recovered from four of the soil replicates with the chromosomal type of 2-8-27 which appeared to have lost one plasmid, but these were not recovered subsequently. Isolate 2-8-27 was among the isolates most sensitive to Zn in laboratory assays, whereas isolate 7-13-1 showed greater zinc tolerance. Acquisition of the plasmid conferred enhanced Zn tolerance to the recipients, but transconjugant isolates were not as metal tolerant as 7-13-1, the putative donor. Laboratory matings between 2-8-27 and 7-13-1 in the presence of Zn resulted in the conjugal transfer of the same small plasmid from 7-13-1 to isolate 2-8-27 and the transconjugant had enhanced metal tolerance. Our results show that transfer of naturally-occurring plasmids among rhizobial strains is stimulated by increased metal concentrations in soil. We further demonstrate that the transfer of naturally-occurring plasmids is important in conferring enhanced tolerance to elevated zinc concentrations in rhizobia.

In nature, plants defend themselves by production of allelochemicals that are toxic to herbivores. There may be considerable genetic variation in the expression of chemical defenses because of various selection pressures. In this study, we examined the development of the small cabbage butterfly, Pieris rapae, and its gregarious pupal ectoparasitoid, Pteromalus puparum, when reared on three wild populations (Kimmeridge, Old Harry, Winspit) of cabbage, Brassica oleracea, and a Brussels sprout cultivar. Wild plant populations were obtained from seeds of plants that grow naturally along the south coast of Dorset, England. Significant differences in concentrations of allelochemicals (glucosinolates) were found in leaves of plants damaged by P. rapae. Total glucosinolate concentrations in Winspit plants, the population with the highest total glucosinolate concentration, were approximately four times higher than in the cultivar, the strain with the lowest total glucosinolate concentration. Pupal mass of P. rapae and adult body mass of Pt. puparum were highest when reared on the cultivar and lowest when developing on Kimmeridge plants, the wild strain with the lowest total glucosinolate concentration. Development of male parasitoids was also more negatively affected than female parasitoids. Our results reveal that plant quality, at least for the development of 'adapted' oligophagous herbivores, such as P. rapae, is not based on total glucosinolate content. The only glucosinolate compound that corresponded with the performance of P. rapae was the indole glucosinolate, neoglucobrassicin. Our results show that performance of ectoparasitoids may closely reflect constraints on the development of the host.

It is widely reported that plants emit volatile compounds when they are attacked by herbivorous insects, which may be used by parasitoids and predators to locate their host or prey. The study of herbivore-induced plant volatiles and their role in mediating interactions between plants, herbivores and their natural enemies have been primarily based on aboveground systems, generally ignoring the potential interactions between above and belowground infochemical- and food webs. This study examines whether herbivory by Delia radicum feeding on roots of Brassica nigra (black mustard) affects the behaviour of Cotesia glomerata, a parasitoid of the leaf herbivore Pieris brassicae, mediated by changes in plant volatiles. In a semi-field experiment with root-damaged and root-undamaged plants C. glomerata prefers to oviposit in hosts feeding on root-undamaged plants. In addition, in a flight-cage experiment the parasitoid also prefers to search for hosts on plants without root herbivores. Plants exposed to root herbivory were shown to emit a volatile blend characterized by high levels of specific sulphur volatile compounds, which are reported to be highly toxic for insects, combined with low levels of several compounds, i.e. beta-farnesene, reported to act as attractants for herbivorous and carnivorous insects. Our results provide evidence that the foraging behaviour of a parasitoid of an aboveground herbivore can be influenced by belowground herbivores through changes in the plant volatile blend. Such indirect interactions may have profound consequences for the evolution of host selection behaviour in parasitoids, and may play an important role in the structuring and functioning of communities.

Online databases are becoming a standard tool to study taxonomy, biodiversity, and ecology. We have developed a comprehensive database for the family Tetranychidae (spider mites). The Tetranychidae is one of the most important families of the Acari in terms of economic impact, because it comprises several agricultural pest species of major relevance, such as the cosmopolitan Tetranychus urticae. The aim of the web site is to gather information on all described spider mites in the world. The main goal is to provide a synthetic view of the biodiversity of this mite family. 1,280 literature references are included, from 1758 to present. 1,257 species, more than 11,745 host plants, and 5,380 geographical data are recorded in 17 tables. The database includes taxonomic data relating the history of nomenclature, geographical distribution, and host plants for all species examined. Three types of query are available to retrieve this information: (1) 'By Species' allows to search on species names and synonyms; (2) 'Advanced' performs a cross search including taxonomical, geographical, and host-plant information; and (3) 'Bibliography' allows searching references combining one, two, or three authors, and it displays all nomenclatural, host plant, and geographical data for the selected reference.

Com o objetivo de estabelecer a duração do desenvolvimento pós-embrionário e dos instares, foram coletados ovos de Anteos menippe em folhas de Cassia ferruginea e levados ao laboratório para o registro das datas das ecdises. O desenvolvimento pós-embrionário durou (média ± erro-padrão) 25,7 ± 0,4 dias. O período larval (15,9 ± 0,3 dias) representou 61,7% do desenvolvimento e contou com cinco instares: L1= 2,2 ± 0,1; L2= 1,7 ± 0,2; L3= 2,0 ± 0,1; L4= 3,4 ± 0,1 e L5= 6,4 ± 0,3. Este último ínstar contou com uma fase ativa (5,4 ± 0,3 dias) e prepupa (1 dia). O período pupal foi de 9,9 ± 0,2 dias. O período de inatividade (prepupa + pupa) foi de 10,9 ± 0,2 dias representando 42,2% do desenvolvimento pós-embrionário, sendo o período ativo (larval ativo) 57,8% do desenvolvimento. A viabilidade de ovos foi de 91,6% e a sobrevivência, a partir do número de lagartas neonatas foi de 59,8%. In order to determine the duration of the post-embryonic development and its instars, eggs of Anteos menippe were collected from Cassia ferruginea leaves and were taken into the laboratory to register the dates of ecdysis. The post-embryonic development was (in days average ± standard error) 25.7 ± 0.4, the larval period 15.9 ± 0.3 represented 61.7% of the development and had five instars: L1 = 2.2 ± 0.1, L2 = 1.7 ± 0.2, L3 = 2.0 ± 0.1, L4 = 3.4 ± 0.1 and L5 = 6.4 ± 0.3. This last instar had an active phase (5.4 ± 0.3) and a prepupal phase (1 day long). The pupal period was 9.9 ± 0.2. The inactivity period (prepupa + pupa) 10.9 ± 0.2 days represented 42.2% of the post-embryonic development, and the active phase 57.8%. The egg viability was 91.6% and the survival, starting from neonate larvae, was 59.8%.

O conhecimento científico sobre a associação de Thysanoptera com plantas nativas ou cultivadas na região Neotropical é praticamente inexistente. Este trabalho objetivou identificar as espécies de tripes e as plantas por eles visitadas ou utilizadas como hospedeiras em uma unidade de conservação, o Parque Estadual de Itapuã (30°22'S 51°02'W), Viamão, Rio Grande do Sul, Brasil. Entre junho de 1999 e maio de 2001, ramos (n=1.274), flores (n=774) e touceiras de gramíneas (n=596) foram sistematicamente amostradas em 20 pontos em quatro transectos estandardizados. O total de 72 espécies de plantas pertencentes a 26 famílias foram identificadas, 60 das quais foram registradas como hospedeiras. Do total de 9.602 espécimes de tripes, 4.900 (50%) foram registrados em flores, 3.764 (39%) em ramos e 938 (10%) nas touceiras de gramíneas. Para 6.533 dos espécimes (4.480 imaturos e 2.053 adultos), foi possível identificar a planta na qual foram coletados. De uma riqueza total de 61 espécies de tripes, 35 foram registradas em flores, 36 em ramos e 14 em touceiras de gramíneas. As espécies de tripes mais abundantes e as plantas que apresentaram a mais alta diversidade de tripes são comentadas. The scientific knowledge about the association of Thysanoptera with native or cultivated plants in the Neotropical region is practically nonentity. This work aimed at identifying the thrips species and the plants visited by them or used as hosts in a Conservation Unit, the "Parque Estadual de Itapuã" (30°22'S 51°02'W), Viamão, Rio Grande do Sul, Southern Brazil. Between June 1999 and May 2001, branches (n=1,274), flowers (n=774) and grass tussocks (n=596) were systematically sampled at 20 points in four standardized transects. A total of 72 plant species belonging to 26 families were identified, 60 of those were registered as host plants. From a total of 9,602 thrips specimens, 4,900 (50%) were registered in flowers, 3,764 (39%) in branches and 938 (10%) in grass tussocks. For 6,533 of the specimens (4,480 immatures and 2,053 adults), it was possible to identify the plant on which they were collected. Of a total richness of 61 species of thrips, 35 were recorded in flowers, 36 in branches and 14 in grass tussocks. The most abundant thrips species and the plant species that showed the higher thrips diversity are commented upon.

Rediscoveiy of the genus Pyrgacris to the Réunion island : description of the male of P. descampsi Kevan, 1975 (Orthoptera, Caelifera). Until now, only two original specimens belonging to the Pyrgacris genus were known : one male from Mauritius, described as P. relictus Descamps, 1968, and one female from Réunion. In spite of the lack of distinguishing traits between these two specimens, the female was subsequently named P. descampsi Kevan, 1975. The recent discovery of a Pyrgacris population in Réunion allows to show that the Pyrgacris from Réunion and Mauritius are clearly distinct species and that P. descampsi must be kept. The justification for higher rank taxa, created to include the Pyrgacris genus, is discussed. The extinction threat to this remarkable genus and more generally to the palmicolous entomofauna of Mascarene Islands is emphasized., A ce jour, le genre Pyrgacris Descamps, 1968, n'était connu que par deux spécimens anciens : un mâle provenant de l'île Maurice et décrit sous le nom de P. relictus Descamps, 1968, et une femelle provenant de l'île de la Réunion. En dépit de l'absence de caractères discriminant le mâle de la femelle, cette dernière a été nommée P. descampsi Kevan, 1975. La récente découverte d'une population de Pyrgacris à la Réunion permet aujourd'hui d'établir que les Pyrgacris de cette île sont bien distincts de ceux de l'île Maurice. Il semble justifié de conserver le nom de Kevan, P. descampsi, pour désigner cette espèce. La justification des taxons d'ordre supérieur érigés pour contenir le genre Pyrgacris est discutée. Enfin, la situation particulièrement critique de ce genre remarquable et des autres espèces palmicoles endémiques des Mascareignes est évoquée., Hugel Sylvain. Redécouverte du genre Pyrgacris à l'île de la Réunion : description du mâle de P. descampsi Kevan, 1975 (Orthoptera, Caelifera). In: Bulletin de la Société entomologique de France, volume 110 (2), juin 2005. pp. 153-159.

1. Plants and insects are part of a complex multitrophic environment, in which they closely interact. However, most of the studies have been focused mainly on bi-tritrophic above-ground subsystems, hindering our understanding of the processes that affect multitrophic interactions in a more realistic framework. 2. We studied whether root herbivory by the fly Delia radicum can influence the development of the leaf feeder Pieris brassicae, its parasitoid Cotesia glomerata and its hyperparasitoid Lysibia nana, through changes in primary and secondary plant compounds. 3. In the presence of root herbivory, the development time of the leaf herbivore and the parasitoid significantly increased, and the adult size of the parasitoid and the hyperparasitoid were significantly reduced. The effects were stronger at low root fly densities than at high densities. 4. Higher glucosinolate (sinigrin) levels were recorded in plants exposed to below-ground herbivory, suggesting that the reduced performance of the above-ground insects was via reduced plant quality. Sinigrin contents were highest in plants exposed to low root fly densities, intermediate in plants exposed to high root fly densities and lowest in plants that were not exposed to root herbivory. 5. Our results show, for the first time, that root herbivory via changes in plant quality can reduce the performance of an above-ground multitrophic level food chain. This underlines the importance of integrating a broader range of above- and below-ground organisms to facilitate a better understanding of complex multitrophic interactions and interrelationships. [KEYWORDS: above–below-ground interactions ; Cotesia glomerata ; Lysibia nana ; Pieris brassicae ; plant–insect interactions]