Submitted by Dominick Jesus (dominickdejesus@hotmail.com) on 2016-02-15T20:10:37Z No. of bitstreams: 2 Dissertação_Sheila Patricia Carvalho Fernandes.pdf: 975862 bytes, checksum: 1989b9a6d2fbfe8fad8f98c3c4a679c8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-15T20:10:37Z (GMT). No. of bitstreams: 2 Dissertação_Sheila Patricia Carvalho Fernandes.pdf: 975862 bytes, checksum: 1989b9a6d2fbfe8fad8f98c3c4a679c8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2010-02-05 / We investigated and characterized the richness of insect galls associated with Burseraceae at Ducke Forest Reserve, Manaus, Amazonas, Brazil. We collected galls monthly on plants previously identified, mapped and marked in the Reserve, from January to June 2009. The galls were taken to laboratory for emergence of adults, count of density and analyses of the associated fauna. Ninety eight galls morphotypes were found associated with 15 Protium species. The majority of galls occurred on leaves, but some were found on petioles. Protium divaricatum supported the highest galls richness with 17 morphotypes. The density of galls per leaflet ranged from 1 to 220. The population fluctuation varied with the gall morphotype and the Protium species, being that P. nitidifolium and P. altsonii supported the highest density in January and June, respectively. The success of emergence was low, only in four morphotypes was possible obtaining the adults. The galls were induced by Diptera and Hemiptera specimens. Cecidomyiidae specimens induced the majority of the galls. The associated fauna was composed by inquilines, predators and parasitoids of Hymenoptera, Diptera and Thysanoptera. The Hymenoptera, represented by eight families, composed the parasitoids fauna. This research corroborates the highest richness of gall-inducing insects in Amazon ecosystems, evidenced by the high diversity of galls found associated with only one plant genus at Ducke Forest Reserve. / O presente estudo objetivou inventariar e caracterizar as galhas de insetos associadas à Burseraceae na Reserva Florestal Ducke, Manaus, Amazonas, Brasil. Foram realizadas coletas mensais de janeiro a junho de 2009. As espécies de Burseraceae estavam previamente identificadas, mapeadas e sinalizadas na Reserva. As galhas coletadas foram levadas ao laboratório para a emergência dos adultos, verificação da abundância e entomofauna associada. Foram encontrados 98 morfotipos de galhas associados a 15 espécies de Burseraceae, todas em Protium. A maioria das galhas ocorreu nas folhas, porém também foram observadas galhas em pecíolo. Protium divaricatum apresentou a maior riqueza de galhas com 17 morfotipos. A abundância de galhas por folíolo variou de 1 a 220. A abundância das galhas variou com o morfotipo de galha e a espécie de Protium, sendo que P. nitidifolium e P. altsonii tiveram as maiores abundâncias em janeiro e junho, respectivamente. Representantes de Diptera e Hemiptera foram os que induziram galhas em Protium na Reserva. Cecidomyiidae foi a família dominante dentre os galhadores. A fauna associada foi composta de inquilinos, predadores e parasitóides representados por Diptera, Hymenoptera e Thysanoptera. Os Hymenoptera, composto por 8 famílias, compuseram a fauna de parasitóides. O estudo confirma a elevada riqueza de insetos galhadores presente em ecossistemas amazônicos, evidenciada pela elevada quantidade de galhas encontradas associadas a apenas um gênero de planta na Reserva Florestal Ducke.

This thesis is an investigation of several aspects of diapause in the swede midge, Contarinia nasturtii (Kieffer). After developing methodology for induction and quantification of diapause entry in the laboratory, heritability of diapause entry was assessed for sibling larvae reared under diapause-inducing conditions. The diapause-quantification technique was efficient, but diapause frequencies were highly variable across studies employing similar diapause-inducing conditions. The diapause entry trait may be weakly heritable. A field study was conducted on diapause entry and emergence patterns. Diapause frequency was inversely correlated with photoperiod and absolute maximum air temperature. Photoperiod did not influence emergence timing. Two emergence phenotypes were observed before mid-July and a third minor emergence phenotype may exist in mid-to-late August. Approximately one third of emergence in the field was attributed to larvae in diapause for two or more years. Avenues of future research on diapause regulation in both the laboratory and field are discussed. / Natural Science and Engineering Research Council (CGS-M), Ontario Ministry of Agriculture, Food, and Rural Affairs (University of Guelph Sustainable Production Program)

Made available in DSpace on 2014-06-12T15:05:50Z (GMT). No. of bitstreams: 2 arquivo4755_1.pdf: 1131987 bytes, checksum: 7b790470ca813ab410db112dc4203a5e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / O ataque por inimigos naturais é um dos fatores de mortalidade mais importantes dos insetos herbívoros, exercendo um forte controle sobre as populações destes organismos. Diversas estratégias de defesas evoluíram entre os herbívoros como resposta à pressão intensa exercida pelo terceiro nível trófico. Particularmente, o significado adaptativo do hábito dos indutores de galhas é constituir um refúgio de proteção contra a dessecação e o ataque por inimigos naturais. Por outro lado, a função protetora das galhas é controversa, visto que a diversidade de parasitóides, predadores e inquilinos associados aos insetos indutores de galhas é enorme. O objetivo geral deste trabalho foi compreender as relações tróficas estabelecidas no sistema composto pelos insetos galhadores, sua planta-hospedeira, Miconia prasina (Melastomataceae) e seus inimigos naturais em quatro fragmentos de floresta Atlântica nordestina. Foram observadas em M. prasina galhas entomógenas do tipo elíptica, esférica e fusiforme nos quatro fragmentos estudados; uma peciolar apenas no Refúgio Charles Darwin; um tipo na gema axilar em Cachoeira e Capoeirão e a galha discóide apenas em Cachoeira em dezembro de 2003. Mensalmente o parasitismo e a predação das galhas esféricas e fusiformes foi acompanhado. Durante um ano, 1007 galhas foram coletadas, destas 762 foram esféricas e 245 fusiformes. A taxa total de predação das galhas foi de 2,28%. A ocorrência dos parasitóides acompanhou os picos populacionais dos galhadores, sendo encontrado em maiores quantidades nos meses de junho e julho. Duas espécies de parasitóides (Hymenoptera) ocorreram em 39,69% das galhas esféricas e fusiformes nos quatro fragmentos. A Mata de Capoeirão e o Refúgio Charles Darwin apresentaram as maiores taxas de predação anual 5,14% e 2,03% respectivamente. A maior taxa de parasitismo foi obtida em Capoeirão (45,28%), porém não houve diferença significativa em relação aos outros fragmentos. A estrutura externa e interna da galha da gema axilar de Miconia prasina (Sw.) DC (Melastomataceae) foi estudada de exemplares provenientes da Mata de Cachoeira e da Mata de Capoeirão. A galha é verde escura, piriforme e possui uma câmara larval. Do ponto de vista anatômico, a galha apresenta na camada mais externa tricomas estrelados, cutícula delgada e epiderme uniestratificada. A região intermediária é composta por células colenquimáticas e parenquimáticas. Um sistema vascular com aspecto sinuoso também está localizado nesta porção. Ao redor da câmara larval, é observado o tecido nutritivo com conteúdo celular conspícuo representado por gotículas lipídicas. A análise anatômica da galha da gema em M. prasina evidenciou alguns caracteres já descritos para outras galhas da família Melastomataceae

Swede midge (Contarinia nasturtii, Diptera: Cecidomyiidae) is a small invasive fly that is currently threatening Brassica vegetable and oilseed production in the Northeastern U.S. and Canada. Larvae feed on plant meristems, resulting in deformed leaves, stems, and heads. Extremely low damage thresholds for heading Brassica vegetables, multiple overlapping generations, and lack of effective organic insecticide options present serious challenges for managing this pest. Pheromone mating disruption (PMD), which involves confusing male insects with unnaturally large doses of sex pheromones, is particularly promising for swede midge management because it prevents mating and subsequent oviposition. One major challenge to PMD for swede midge management is that the chiral female pheromone blend, a 1:2:0.02 blend of (2S, 9S)-diacetoxyundecane, (2S, 10S)-diacetoxyundecane and (S)-2-acetoxyundecane, is expensive to synthesize due to the structural complexity of the compounds. Here, we explored three ways to reduce the cost of swede midge PMD: the use of lower-cost racemic pheromones containing all possible stereoisomers, single-component blends, and the possibility of using timed pheromone dispensers by testing for diel patterns of midge reproductive behavior. Although we found that males were not attracted to blends containing the racemic stereoisomers of the main pheromone component, (2S, 10S)-diacetoxyundecane, racemic blends functioned equally as well as chiral blends in confusing males and altering female behavior in PMD systems. We observed 95% and 87% reductions in males caught in monitoring traps in three-component chiral and racemic PMD plots of broccoli, respectively. In addition to confusing males, we also found that females altered their reproductive behavior in response to both chiral and racemic pheromones. Females released pheromones more frequently when exposed to three-component chiral and racemic blends, and were less likely to mate afterward. Single-pheromone treatments containing either chiral or racemic 2,10-diacetoxyundecane neither confused males nor influenced female behavior. We identified a total of eight hours during the day and night when midges do not exhibit mate-seeking behavior, during which programmable PMD dispensers could be turned off to save pheromone inputs. We found that up to 81% of females released pheromones to attract males for mating in the early morning shortly after dawn. Most females emerged in the morning as well, releasing pheromones soon after eclosing. Because midges are receptive to mates shortly after emergence, they may mate at their emergence site. Overall, we found relatively high levels of crop damage in our pheromone-treated plots, likely due to the migration of mated females into our plots. If midges mate at emergence sites, rotation of Brassica vegetable crops may result in overwintered midges emerging in fields where host plants are not currently grown. Further research is needed to determine where midges mate in order to determine where to install PMD dispensers.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a key pest of wheat, Triticum aestivum L. (Poaceae), in the Canadian Prairies. The larvae destroy wheat kernels, resulting in reduction of quality and quantity of wheat. Deployment of antixenotic wheat lines, which suppress oviposition of wheat midge, can reduce damage in wheat fields. The objectives of this thesis were to explore the interactions between wheat midge and spring wheat with emphasis on oviposition behavior and to explore the antixenosis of wheat to oviposition from the point of view of genetics and crop breeding. In this research, a doubled-haploid spring wheat population was studied, which was the progeny of a cross between a susceptible wheat cultivar ‘Roblin’ and a resistant (antixenotic and antibiotic) wheat line ‘Key 10’. Oviposition of wheat midge on wheat spikes in the laboratory was affected by visual and chemical cues. The visual contrast between wheat spikes and the background color in the laboratory was important in modifying oviposition of wheat midge on wheat spikes. Low contrast resulted in low egg density on wheat spikes in the laboratory. The egg density on wheat spikes in the laboratory decreased when the background color of the spikes was red or black; while yellow and blue backgrounds did not decrease egg density on the spikes. The laboratory study provided evidence that wheat midge oviposition was affected by volatiles emitted by wheat spikes. The volatiles of spikes of a post-anthesis susceptible wheat cultivar, ‘Roblin’, and a pre-anthesis resistant wheat line, ‘Key 10’, significantly suppressed the oviposition of wheat midge in the laboratory. It is hypothesized that these volatiles might be a factor in antixenosis of wheat against wheat midge in the doubled-haploid population studied. It is suggested that the differences of oviposition behavior in susceptible and antixenotic wheats, which was observed in the laboratory, might be due to volatiles emitted by wheat spikes. However, other factors such as tactile cues might also be involved. The observation of oviposition behavior in the laboratory on the susceptible wheat cultivar ‘Roblin’ showed that wheat midge started ovipositing sooner, stayed longer, laid more eggs and left the spike sooner after the last oviposition than on the antixenotic line ‘Key 10’. However, the time required for laying one egg was similar when wheat midge was on the susceptible or resistant wheat. The observed antennation behavior of wheat midge while probing the wheat spike might indicate that wheat midge probed for chemical cues emitted by the host plant. The observed ovipositor tapping and dragging on the wheat spike surface while probing the spike suggested that there might be receptors at the tip of the ovipositor which receive tactile cues from the plant surface, guiding oviposition. The correlations between morphological traits of bread wheat spikes and antixenosis in the laboratory were not high enough to conclude that those traits were associated with antixenosis. However, more research on fine scale morphological traits of the spike may reveal relationships with antixenosis. Based on data from a laboratory trial and trials in the field over two field seasons, it was concluded that the antixenosis to wheat midge in the doubled-haploid population was probably conferred by two genes with complementary interactions among genes, and a heritability of 67%. In the two field seasons, the least preferred line received 13% and 11% as many eggs as on ‘Roblin’; ‘Key 10’ received 57% and 20% as may eggs as on ‘Roblin’. Our study did not provide evidence for linkage between antixenosis genes and the antibiosis gene, Sm1, which is associated with death of larvae of wheat midge. The antixenosis of spring wheat against wheat midge can be considered as a promising mechanism for suppressing wheat midge oviposition in the field. More research is required to reveal additional genetic information which would help crop breeders in production of cultivars antixenotic to wheat midge.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a key pest of wheat, Triticum aestivum L. (Poaceae), in the Canadian Prairies. The larvae destroy wheat kernels, resulting in reduction of quality and quantity of wheat. Deployment of antixenotic wheat lines, which suppress oviposition of wheat midge, can reduce damage in wheat fields. The objectives of this thesis were to explore the interactions between wheat midge and spring wheat with emphasis on oviposition behavior and to explore the antixenosis of wheat to oviposition from the point of view of genetics and crop breeding. In this research, a doubled-haploid spring wheat population was studied, which was the progeny of a cross between a susceptible wheat cultivar ‘Roblin’ and a resistant (antixenotic and antibiotic) wheat line ‘Key 10’. Oviposition of wheat midge on wheat spikes in the laboratory was affected by visual and chemical cues. The visual contrast between wheat spikes and the background color in the laboratory was important in modifying oviposition of wheat midge on wheat spikes. Low contrast resulted in low egg density on wheat spikes in the laboratory. The egg density on wheat spikes in the laboratory decreased when the background color of the spikes was red or black; while yellow and blue backgrounds did not decrease egg density on the spikes. The laboratory study provided evidence that wheat midge oviposition was affected by volatiles emitted by wheat spikes. The volatiles of spikes of a post-anthesis susceptible wheat cultivar, ‘Roblin’, and a pre-anthesis resistant wheat line, ‘Key 10’, significantly suppressed the oviposition of wheat midge in the laboratory. It is hypothesized that these volatiles might be a factor in antixenosis of wheat against wheat midge in the doubled-haploid population studied. It is suggested that the differences of oviposition behavior in susceptible and antixenotic wheats, which was observed in the laboratory, might be due to volatiles emitted by wheat spikes. However, other factors such as tactile cues might also be involved. The observation of oviposition behavior in the laboratory on the susceptible wheat cultivar ‘Roblin’ showed that wheat midge started ovipositing sooner, stayed longer, laid more eggs and left the spike sooner after the last oviposition than on the antixenotic line ‘Key 10’. However, the time required for laying one egg was similar when wheat midge was on the susceptible or resistant wheat. The observed antennation behavior of wheat midge while probing the wheat spike might indicate that wheat midge probed for chemical cues emitted by the host plant. The observed ovipositor tapping and dragging on the wheat spike surface while probing the spike suggested that there might be receptors at the tip of the ovipositor which receive tactile cues from the plant surface, guiding oviposition. The correlations between morphological traits of bread wheat spikes and antixenosis in the laboratory were not high enough to conclude that those traits were associated with antixenosis. However, more research on fine scale morphological traits of the spike may reveal relationships with antixenosis. Based on data from a laboratory trial and trials in the field over two field seasons, it was concluded that the antixenosis to wheat midge in the doubled-haploid population was probably conferred by two genes with complementary interactions among genes, and a heritability of 67%. In the two field seasons, the least preferred line received 13% and 11% as many eggs as on ‘Roblin’; ‘Key 10’ received 57% and 20% as may eggs as on ‘Roblin’. Our study did not provide evidence for linkage between antixenosis genes and the antibiosis gene, Sm1, which is associated with death of larvae of wheat midge. The antixenosis of spring wheat against wheat midge can be considered as a promising mechanism for suppressing wheat midge oviposition in the field. More research is required to reveal additional genetic information which would help crop breeders in production of cultivars antixenotic to wheat midge.

Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-31T00:27:30Z No. of bitstreams: 1 414902.pdf: 35625932 bytes, checksum: cca8a05543524fdf753fb225fec9ff84 (MD5) / Made available in DSpace on 2018-01-31T00:27:30Z (GMT). No. of bitstreams: 1 414902.pdf: 35625932 bytes, checksum: cca8a05543524fdf753fb225fec9ff84 (MD5) Previous issue date: 1999-09-09 / CAPES / FUJB / Nas restingas da Barra de Maricá, ltaipuaçu e Carapebus foram encontradas 108 espécies de Cecidomyiinae associadas a 53 espécies de plantas distribuídas em 42 gêneros e 32 famílias. Noventa e três espécies de Cecidomyiinae eram cecidógenas, 4 predadoras, 5 inquilinas de galhas e 6 tinham larvas livres. As espécies galhadoras estavam associadas a 47 espécies de plantas (36 gêneros e 28 famílias). A maioria das galhas era foliar (63), 13 desenvolveram-se a partir das gemas, 9 ocorreram na inflorescência, botão ou pedúnculo floral, 3 no fruto e 1 na gavinha. As Myrtaceae destacaram-se como a família de planta com maior riqueza de galhas, seguidas das Burseraceae, Nyctaginaceae, Sapotaceae, Erythroxylaceae, Malpighiaceae e Solanaceae. Onze gêneros novos e quatorze novas espécies de Cecidomyiinae foram descritos (larva, pupa, macho, fêmea e galha), larva de três espécies e pupa de duas outras foram descritas, duas novas combinações foram propostas e novos registros de plantas hospedeiras e de localidades foram assinalados. Na restinga da Barra de Maricá foram encontradas 79 espécies de Cecidomyiinae, em Carapebus 64 e em ltaipuaçu 41. O índice de Sorensen revelou que a restinga da Barra de Maricá e de Itaipuaçu são mais similares entre si quanto à fauna de Cecidomyiinae, confirmando uma relação positiva entre proximidade geográfica e similaridade faunística. / At "restingas" of Barra de Maricá, Itaipuaçu and Carapebus, 108 species of Cecidomyiinae were found in association with 53 plant species distributed among 42 genera and 32 families. 93 Cecidomyiinae species were cecidogenous, 4 predators, 5 inquilines of galls and 6 had free living larvae . Gall maker species were associated with 47 plant species (36 genera and 28 families). The majority of the galls were leaf ones (63); 13 developed from bud; 9 occurred in inflorescence, closed flower or flower peduncle; 3 in fruits and 1 in clasper. The Myrtaceae were the first plant family in richness of galls followed by Burseraceae, Nyctaginaceae, Sapotaceae, Erythroxylaceae, Malpighiaceae and Solanaceae. 11 new genera and 14 new species of Cecidomyiinae were described (larva, pupa, male, female and gall), larva of 3 species and pupae of 2 others were described, 2 new combinations were proposed and new records of host plants and Iocalities registered. 79 Cecidomyiinae species were found at "restinga" of Barra de Maricá, 64 at Carapebus e 41 at Itaipuaçu. Sorensen index revealed that the "restingas" of Barra de Maricá and ltaipuçu are more similar in Cecidomyidae fauna, confirming a positive relation between geographical proximity and fauna similarity.

Les relations complexes qui unissent les insectes phytophages et les plantes peuvent être étudiées par des approches interdisciplinaires à diverses échelles. Ces études peuvent avoir un intérêt appliqué, dans l'agriculture notamment. Au cours de cette thèse, nous avons mené une étude interdisciplinaire sur la biologie de la cécidomyie des fleurs du manguier, Procontarinia mangiferae (Felt) (Diptera : Cecidomyiidae), un bio-agresseur monophage et invasif responsable de dégâts économiques majeurs dans plusieurs zones de production du monde. L'objectif était d'améliorer les connaissances sur la biologie de cette espèce à l'île de la Réunion : (1) en évaluant sa diversité génétique et les facteurs écologiques et biologiques qui peuvent expliquer la structuration génétique de ses populations ; (2) en étudiant en milieu naturel ou contrôlé les caractéristiques de sa diapause, qui lui permettent de maintenir des populations d'une saison de floraison à la suivante ; (3) en étudiant par modélisation la dispersion des femelles dans un verger lors de sa colonisation, en prenant en compte les capacités de vol et la distribution spatiale et temporelle des stades sensibles du manguier au sein du verger. Les résultats ont montré que l'espèce P. mangiferae se reproduisait à la fois sur les inflorescences et sur les jeunes feuilles, qu'elle était présente toute l'année et sur tous les sites échantillonnés sur l'île, quelles que soient les conditions culturales ou climatiques. Ses populations sont apparues structurées en deux clusters sympatriques, dont un était plus fréquent dans la zone de culture du manguier. Ensuite, nous avons prouvé l'existence d'une diapause facultative induite toute l’année, avec cependant un taux d'induction de diapause supérieur en été. Cette diapause du troisième stade larvaire se déroule dans le sol et dure entre six semaines et plus d'un an. Les températures fraiches déclenchent les émergences des individus en diapause et permettent de synchroniser l'émergence des adultes avec la période de floraison du manguier. Enfin, nous avons montré que des femelles immigrantes étaient capables de coloniser l'ensemble des arbres d'un verger. Le vol d'arrivée des femelles dans le verger et le vol actif au sein du verger se sont avérés influencés respectivement par l'abondance et par l'attractivité de la ressource. Les connaissances obtenues sur la biologie de P. mangiferae et sur ses relations avec le manguier ouvrent des pistes pour le développement de stratégies de gestion agroécologique de ce bio-agresseur. / Phytophagous insects and plants are linked by complex relationships. Insect-plant interaction researches involve several biological disciplines at different levels of analysis. These insect–plant relationships are of crucial importance from an applied point of view, notably for agriculture. In this work, an interdisciplinary approach has been used to study on the mango blossom gall midge, Procontarinia mangiferae (Felt) (Diptera: Cecidomyiidae), an invasive insect pest specific to mango causing major economic damages worldwide. The objective was to improve our knowledge of the biology of this species in the subtropical Reunion Island (i) by describing its genetic diversity and investigate the ecological and biological determinants of the genetic structure of its populations, (ii) by carrying out field and controlled experiments to understand the diapause strategies involved in maintaining populations from one flowering season to the next one, (iii) by modeling the arrival and dispersion of females within an orchard in relation with their flight capacity and with the spatial and temporal distribution of the mango susceptible resources. The results showed that the single species P. mangiferae, feeding on both inflorescences and young leaves, was present all year round and in all the sampled sites on the island, regardless of the climatic and cultural conditions. Populations in Reunion Island appeared structured into two clusters in sympatry, one cluster being more frequent in the cultivated mango area. Secondly, we demonstrated the occurrence of facultative diapause all year round, with the highest rate of diapause observed in summer. The diapause allowed a developmental arrest at the 3rd larval instar in the soil, lasting between six weeks to more than one year. The decrease of temperature at the beginning of winter triggered off the emergence of diapausing individuals and synchronized adult emergence with the mango flowering period. Thirdly, non-native female gall midges were able to colonize all the trees of an orchard. Their arrival flight and trivial flight were oriented by the abundance and by the attractiveness of the mango resources, respectively. The knowledge obtained on the biological cycle of P. mangiferae and on its relationships with the mango tree should be useful to develop new agroecological pest management strategies.

Tesis por compendio / [EN] Aphis spiraecola Patch. (Hemiptera: Aphididae) is a key pest of clementines. Biological control of A. spiraecola is still poorly known and efforts were based on the use and conservation of parasitoids but it did not success. With all this said, the aims of this thesis were: i) to disentangle the reasons behind the low parasitism of A. spiraecola; ii) to determine when and how predators can control A. spiraecola populations; and, finally, iii) to evaluate whether a ground cover of Poaceae plants can enhance the biological control of this aphid in clementines by improving the establishment of its predators. In the first objective we sampled four orchards and determine the parasitoid complex and parasitism (and hyper-) rates weekly. Binodoxys angelicae Haliday (Hymenoptera: Braconidae) was the unique primary parasitoid emerged from mummies of A. spiraecola. At least six hymenopteran hyperparasitoid species were identified attacking this primary parasitoid: Syrphophagus aphidivorus (Mayr) (Encyrtidae), Alloxysta sp. (Forster) (Figitidae), Asaphes sp. (Walker) (Pteromalidae), Pachyneuron aphidis (Bouché) (Pteromalidae), Dendrocerus sp. (Ratzeburg) (Megaspilidae) and Phaenoglyphis villosa (Hartig) (Figitidae). We developed a DNA-based approach to untangle the structure of the aphid-parasitoid food web in citrus. This methodology confirmed that all six species hyperparasitized B. angelicae And they dominated this food web and they were abundant from the beginning of the season. Thus, hyperparasitism probably explains the low impact of B. angelicae on A. spiraecola populations. For the second objective we sampled three clementine orchards to determine the effect of aphid predators on A. spiraecola colonies over a three-year period. Life parameters of A. spiraecola colonies varied among the orchards over the three years. The maximum number of aphids and the longevity of A. spiraecola colonies were negatively correlated with the time of first attack by predators. More importantly, the percentage of shoots occupied by A. spiraecola (damages) remained below or close to the intervention threshold when colonies were attacked prior to ~200 degree days (DD) since the beginning of the aphid colonization. These results suggest that: i) the presence of predators at the beginning of the season should be considered to develop new intervention thresholds and ii) biological control programs should promote the early presence of predators in clementine orchards. To promote the early presence of predators in clementine orchards, in the third objective we evaluated ground cover management. This ground cover management may provide alternative preys to natural enemies. The effect of a sown ground cover (based on Poaceae plants) on the biological control of A. spiraecola was evaluated in four orchards with ground cover management compared with four orchards with bare soil management. This sown Poaceae cover coexists with a complex of wild plants that might also affect biological control of A. spiraecola. Finally, we compared the presence of A. spiraecola and its natural enemies in these orchards. While Poaceae plants represented ~66% of the ground cover, the rest of the cover comprised mainly Malva sp. (13%), Oxalis sp. (5%) and Sonchus sp. (2%). Poaceae plants harbored aphids which appeared sooner in the system than citrus aphids. These aphids serve as alternative prey/hosts for natural enemies. By contrast, Malva sp. and Sonchus sp. harbored aphids with potential to become citrus pest. Although these wild plants may act as reservoirs for A. spiraecola as well as other aphid species that can disrupt the biocontrol services of natural enemies, overall, the sown cover was effective in terms of biological control of A. spiraecola in the citrus canopy. It promoted the early presence of predators in citrus canopies. These attacks resulted in satisfactory aphid control, because citrus orchards with ground cover never exceeded the aphid economic threshold. / [ES] Aphis spiraecola Patch. (Hemiptera: Aphididae) es una de las plagas claves en el cultivo de clementinos. Los esfuerzos realizados hasta la fecha se han centrado en el uso y conservación de parasitoides aunque se desconocen las causas de su baja eficacia. Por todo ello, los objetivos de esta tesis han sido i) desentrañar las razones por las que se dan bajos niveles de parasitismo de A. spiraecola ii) determinar cuándo y cómo los depredadores pueden controlar las poblaciones de A. spiraecola y finalmente iii) determinar si una cubierta de poáceas puede mejorar el control biológico de este pulgón en clementinos mediante la mejora en el establecimiento de sus depredadores. En el primer objetivo se muestrearon semanalmente cuatro parcelas y se identificó el complejo de parasitoides y las tasas de parasitismo (e hiperparasitismo). Los porcentajes de parasitismo fueron bajos (~menos del 5%) y Binodoxys angelicae Haliday (Hymenoptera: Braconidae) fue el único parasitoide primario emergido de las momias de A. spiraecola. Se identificaron al menos seis especies de hiperparasitoides atacando este parasitoide primario: Syrphophagus aphidivorus (Mayr) (Encyrtidae), Alloxysta sp. (Forster) (Figitidae), Asaphes sp. (Walker) (Pteromalidae), Pachyneuron aphidis (Bouché) (Pteromalidae), Dendrocerus sp. (Ratzeburg) (Megaspilidae) y Phaenoglyphis villosa (Hartig) (Figitidae). Se desarrolló un método basado en la detección de ADN con el cual se confirmó que todas las especies de hiperparasitoides hiperparasitan B. angelicae. Los hiperparasitoides dominaron esta red trófica y fueron abundantes desde el inicio de la estación. De este modo, el hiperparasitismo probablemente explica el bajo impacto que B. angelicae tiene sobre las poblaciones de A. spiraecola. Para el segundo objetivo se muestrearon tres campos de clementinos donde se determinó el efecto de los depredadores en las colonias de A. spiraecola. Los parámetros de vida de las colonias de A. spiraecola variaron entre los diferentes cultivos los tres años. El máximo número de pulgones y la longevidad de las colonias de A. spiraecola se correlacionaron negativamente con el momento del primer ataque del depredador a la colonia. Cabe destacar que el porcentaje de brotes ocupados por A. spiraecola permaneció por debajo o cerca del umbral de tratamiento cuando las colonias fueron atacadas antes de los 200 grados días (GD) desde el inicio de formación de la colonia. Estos resultados sugieren: i) la presencia de depredadores al inicio de la temporada de pulgón debes ser considerado para el desarrollo de nuevos umbrales de tratamiento y ii) los programas de control biológico deben promover el adelanto de la presencia de depredadores en los campos de clementinos. Para promover la presencia anticipada de depredadores en los campos de clementinos, como tercer objetivo se evaluó el manejo de cubiertas vegetales a base de poáceas. Con este manejo se persigue aportar presas alternativas para los enemigos naturales de A. spiraecola. Para ello, se compararon cuatro campos de cítricos con cubierta vegetal frente a cuatro con suelo desnudo. En los campos con cubierta sembrada apareció además de las poáceas sembradas, un complejo de plantas salvajes que podrían afectar también el control biológico de A. spiraecola. Las poáceas representaron un 66% de la cubierta vegetal. Las poáceas y Oxalis sp. albergaron respectivamente pulgones estenófagos de plantas poáceas y Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae). Estas especies de pulgones aparecieron más pronto en el ecosistema que los pulgones de cítricos y sirvieron como presas/hospederos alternativos para los enemigos naturales. Al contrario, Malva sp. y Sonchus sp. albergaron especies de pulgón que podrían ser potenciales plagas de cítricos. El efecto total de la cubierta sembrada resultó positivo para el control de A. spiraecola. Por lo tanto, las parcelas de cítricos con cubierta vegetal tendieron a no / [CA] Aphis spiraecola Patch. (Hemiptera: Aphididae) és una de les plagues clau en el cultiu de clementins. Els esforços realitzats fins ara s'han centrat en el us i conservació de parasitoids encara que es desconeix les causes de la seua baixa eficàcia. Tenint en compte estos antecedents, els objectius d'esta tesis foren: i) desentrampar les raons per les quals els parasitoids no són efectius; ii) determinar quan i com els depredadors poden controlar les poblacions d'A. spiraecola; i finalment iii) determinar si una coberta de poàcies pot millorar el control biològic d'este àfid en clementins mitjançant la millora en el establiment del seus depredadors. En el primer objectiu es van mostrejar setmanalment quatre parcel·les i s'identificà el complex de parasitoids i les taxes de parasitisme (i hiperparasitisme). Binodoxys angelicae Haliday (Hymenoptera: Braconidae) va ser l'únic parasitoid primari emergit de les mòmies d'A. spiraecola. Se van identificar al menys sis especies d' hiperparasitoids atacant este parasitoid primari: Syrphophagus aphidivorus (Mayr) (Encyrtidae), Alloxysta sp. (Forster) (Figitidae), Asaphes sp. (Walker) (Pteromalidae), Pachyneuron aphidis (Bouché) (Pteromalidae), Dendrocerus sp. (Ratzeburg) (Megaspilidae) i Phaenoglyphis villosa (Hartig) (Figitidae). Se desenvolupà un mètode basat en la detecció de DNA amb el que es confirmà que totes les especies d'hiperparasitoids hiperparasiten B. angelicae. Els hiperparasitoids dominaren aquesta xarxa tròfica i foren abundants a l'inici de l'estació. Per tant, l'hiperparasitisme podria explicar el baix impacte que B. angelicae té sobre les poblacions d'A. spiraecola. Per al segon objectiu es mostrejaren tres camps de clementins on es determinà l'efecte dels depredadors en les colònies d'A. spiraecola. Els paràmetres de vida de les colònies d'A. spiraecola variaren entre les tres parcel·les els tres anys. El màxim número d'àfids i la longevitat de les colònies d'A. spiraecola es correlacionaren negativament amb el moment del primer atac del depredador a la colònia. Caldria destacar que el percentatge de brots ocupats per A. spiraecola es mantingué per baix o prop del llindar de tractament quan les colònies foren atacades abans dels ~200 graus dia (GD) des de l'inici de formació de la colònia. Estos resultats sugereixen que: i) la presència de depredadors a l'inici de la estació de l'àfid podria ser considerada per al desenvolupament de nous llindars de tractament i ii) els programes de control biològic deurien promoure l'avançament de la presència de depredadors en els camps de clementins. Per promoure la l'avançament de la presència de depredadors en els camps de clementins, com tercer objectiu s'avaluà el maneig de cobertes vegetals basades en poàcies. Amb aquest maneig es persegueix aportar preses alternatives per als enemics naturals d'A. spiraecola. Se compararen quatre camps de clementins amb coberta vegetal front a quatre amb sol nu. En els camps amb coberta sembrada creix, junt a les Poáceas sembrades, un conjunt de plantes salvatges que podrien afectar també el control biològic d'A. spiraecola. S'investigà quines especies de plantes componien la coberta vegetal així com les especies d'àfids que les habitaven. Les poàcies representaren un 66% de la coberta vegetal, sent les plantes salvatges més abundants Malva sp. (13%), Oxalis sp. (5%) i Sonchus sp. (2%). Les poàcies hostejaren àfids estenòfags de poàcies. Estes espècies d'àfid aparegueren més prompte en l'ecosistema que aquells àfids associats a cítrics. Al contrari, Malva sp. i Sonchus sp. hostejaren especies d'àfids que podrien ser potencials plagues de cítrics. Este últim grup pot atenuar l'atac dels enemics naturals a les poblacions d'A. spiraecola que habiten les copes. Encara així, l'efecte total de la coberta sembrada a base de poàcies va resultar positiu per al control d'A. spiraecola. En conseqüència les parcel·les de cítrics am / Gómez Marco, F. (2015). Integrated Pest Management of Aphis spiraecola (Hemiptera: Aphididae) in clementines: enhancing its biological control [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53732 / Compendio