Lasioderma serricorne (F.) (Fabricius, 1792) (Coleoptera: Anobiidae) is a cosmopolitan plague popularly known as a tobacco beetle that attacks a wide variety of stored agricultural products, like soybeans, escavating galleries in the grains while feeding and consequently generating losses to the producers by the loss of quality and value of the seeds. Due to the risks of intoxication and environment contamination with chemical residues, as well as the emergence of resistant individuals, other approaches to the control of L. serricorne have been sought. The host plant kairomones are molecules with potential for application as food attractants in traps for monitoring and capture insects. On the other hand, the evaluation of essential oils (EO) of native plants cultivated locally, can contribute to the discovery of useful compounds as natural repellents or bio-insecticides, also generating tools useful in integrated pest management (IPM). The objective of this study was to investigate and identify the volatile organic compounds released by stored soybeans from 3 varieties cultivated in Brazil with attractiveness to adults L. serricorne (soybean marketed in large supermarket chains in Maceió-AL and two varieties EMBRAPA BRS284 and BRS360RR) and to test the EO activity of the mature fruits of Schinus terebinthifolius, in order to promote the prospection of natural compounds with potential for application in the integrated management of this pest in storage environments. The attractiveness of grains and extracts prepared by dynamic headspace collection was evaluated in 4-arm olfactometer behavioral bioassays, while the isolation and identification of the bioactive compounds were carried out using gas chromatography coupled to electroanthennography (GC-EAG) and gas chromatography coupled to mass spectrometry (GC-MS). Five EAG-active compounds were identified in the extracts of soybeans: 1-octen- 3-ol, 3-octanol, 1- nonanol, linalool and limonene. The behavioral response of L. serricorne in 4-arm olfactometer bioassays to synthetic compounds was statistically significant for 1- octen-3- ol, 3-octanol, 1-nonanol and linalool, while the attraction for the 4 synthetic blend was comparable to that verified for soybeans. The activity of the EO extracted by steam-drag of the mature fruits of S. terebinthifolius (3 replicates) harvested from matrices located on the A. C. Simões Campus of UFAL, Maceió-AL, on L. serricorne adults was tested in 4-arm olfactometer bioassays , in two concentrations (1 and 10 μL), while the EO composition was analyzed by GC-FID and GC-MS. EO repellency was checked at a dose of 10 μL. A total of 14 compounds were identified in S. terebinthifolius EO, with the main components being β-pinene (49.8%), α-pinene (33.49%), 3-carene (5.85%), germacrene-D (2.08%) and bornylene (1.21%). The attractive compounds identified from the soybean grains act as kayromones for L. serricorne, while the S. terebinthifolius EO has repellent activity against this pest, so the results obtained here can be applied in the development of bioproducts for the integrated management of L. serricorne in and around storage environments, favoring the rational use of insecticides. / Lasioderma serricorne (F.) (Fabricius, 1792) (Coleoptera: Anobiidae) é uma praga cosmopolita conhecida popularmente como besourinho do tabaco que ataca uma grande variedade de produtos agrícolas armazenados, dentre eles a soja, escavando galerias nos grãos enquanto se alimentam e consequentemente gerando prejuízos aos produtores pela perda da qualidade e valor das sementes. Devido aos riscos de intoxicação e de contaminação do meio ambiente com resíduos químicos, assim como o surgimento de indivíduos resistentes, outras abordagens para o controle de L. serricorne tem sido buscadas. Os cairomônios das plantas hospedeiras são moléculas com potencial para aplicação como atraentes alimentares em armadilhas para monitoramento e captura de insetos. Por outro lado, a avaliação de óleos essenciais (OE) de plantas nativas cultivadas localmente, pode contribuir para a descoberta de compostos úteis como repelentes ou bioinseticidas naturais, gerando também ferramentas úteis manejo integrado de pragas (MIP). O objetivo desse estudo foi investigar e identificar os compostos orgânicos voláteis liberados pelos grãos de soja armazenados de três variedades cultivadas no Brasil com atratividade para adultos de L. serricorne (soja comercializada em grandes cadeias de supermercados em Maceió-AL e duas variedades EMBRAPA BRS284 e BRS360RR) e testar a atividade do OE dos frutos maduros de Schinus terebinthifolius, a fim de promover a prospecção de compostos naturais com potencial para aplicação no manejo integrado dessa praga em ambientes de armazenamento. A atratividade dos grãos e de extratos preparados por coleta dinâmica do headspace dos grãos foi avaliada em bioensaios comportamentais em olfatômetro de 4 braços, enquanto o isolamento e identificação dos compostos bioativos foram realizados pelas técnicas de cromatografia gasosa acoplada à eletroantenografia (CG-EAG) e cromatografia gasosa acoplada à espectrometria de massas (CG-EM). Cinco compostos EAG-ativos foram identificados nos extratos dos grãos de soja: 1-octen- 3-ol, 3-octanol, 1-nonanol, linalol e limoneno. A resposta comportamental de L. serricorne em bioensaios em olfatômetro de 4 braços aos compostos sintéticos foi estatisticamente significativa para 1-octen- 3-ol, 3-octanol, 1- nonanol e linalol, enquanto a atração pela mistura dos 4 compostos sintéticos foi comparável à verificada para os grãos de soja. A atividade do OE extraído por arraste a vapor dos frutos maduros de S. terebinthifolius (3 repetições) colhidos de matrizes localizadas no campus A. C. Simões da UFAL, Maceió-AL, sobre adultos de L. serricorne foi testada em bioensaios em olfatômetro de 4 braços, em duas concentrações (1 e 10μL), enquanto a composição do OE foi analisada por CG-FID e CG-EM. Foi verificada repelência do OE na dose de 10 μL. Foram identificados 14 compostos no OE de S. terebinthifolius, sendo os componentes principais: β-pineno (49,8 %), α-pineno (33,49 %), 3-careno (5,85 %), germancreno-D (2,08 %) e bornileno (1,21 %). Os compostos atrativos identificados a partir dos grãos de soja atuam como cairomônios para L. serricorne, enquanto o OE de S. terebinthifolius possui atividade repelente contra essa praga, portanto os resultados aqui obtidos podem ser aplicados no desenvolvimento de bioprodutos para o manejo integrado de L. serricorne dentro e ao redor de ambientes de armazenamento, favorecendo a utilização racional de inseticidas.

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<p>  </p> <p>Environmental conditions, like light quality and herbivory, can induce changes in plant physiology. Light quality can be manipulated using LEDs (light emitting diodes) to improve crop quality and yield in horticultural production. The manipulation of light quality has also been utilized in the management of agricultural insect pests. Previous research has provided evidence that changes in light quality can have effects on the growth and chemistry of cannabis crops (<em>Cannabis spp.</em>). Varieties of cannabis are grown for the production of the valued cannabinoids CBD and THC. Pest of cannabis include herbivorous arthropods that reduce hemp yield and quality. Arthropod herbivory can induce chemical and physical changes in plants. This thesis further investigates the role of light quality on both cannabis biology and the crop-pest interaction between cannabis and the cannabis aphid (<em>Phorodon cannabis</em>). In the experiments described herein, the effects of light quality and <em>P. cannabis </em>herbivory on cannabis were assessed by measuring impact on biomass accumulation, yield, and the production of CBD and THC. The effects of light quality on the life history traits of <em>P. cannabis </em>were also measured. Cannabis grown under red-blue light quality saw a reduction in vegetative growth but no reduction in yield. Light treatments had no measured effect on the concentrations of CBD and THC in the cannabis buds. Aphid herbivory decreased bud yield but increased vegetative growth. Aphid herbivory reduced the concentration of both CBD and THC in cannabis bud tissue. Under blue-rich light quality, <em>P. cannabis </em>experienced higher reproductive rates when compared to red-blue and full-spectrum lighting. </p>

Since many years, the agro-technical programs such as '3 reduction 3 increase', '1 must 5 reduction' and System of Rice Intensification (SRI) have been carried out with definite results. Recently, IPM program (integrated pest management) – a more comprehensive measure (using all possible techniques and methods to keep the pest populations below a level causing economic injury) – has been firstly piloted on a large scale in the Mekong Delta. This paper presents the main results of piloting IPM program in 2,610 hectares during 2014-2017 in Hau Giang province. As results, farmers have better economic benefit in production; the quality of rice has been gradually improved and can overcome the technical barriers of advanced countries in rice trade such as US, EU and Japan. In addition, the environmental and ecological consequences can be avoided due to overuse of fertilizer and pesticide. Field ecosystems will be gradually restored. / Từ nhiều năm nay những chương trình kỹ thuật nông nghiệp như '3 giảm 3 tăng', '1 phải 5 giảm' và hệ thống canh tác lúa cải tiến (SRI) đã được áp dụng và đã có những kết quả nhất định. Còn chương trình quản lý dịch hại tổng hợp IPM - một biện pháp tổng hợp và tích cực hơn (sử dụng tất cả các kỹ thuật và biện pháp thích hợp có thể được, nhằm duy trì mật độ của các loài gây hại dưới mức gây ra những thiệt hại kinh tế) – được thực nghiệm đầu tiên trên diện rộng ở Đồng bằng sông Cửu Long. Bài báo này trình bày những kết quả chính trong thử nghiệm ở 2.610 ha lúa trong thời gian 2014-2017 ở ở tỉnh Hậu giang. Kết quả là quản lý dịch hại ở ngưỡng cho phép, người nông dân có lợi hơn về kinh tế trong sản xuất, chất lượng gạo từng bước được cải thiện và có khả năng vượt qua các hàng rào kỹ thuật trong thương mại lúa gạo của các nước tiên tiến như USA, châu Âu, Nhật Bản. Ngoài ra tránh được hệ quả về môi trường sinh thái do sử dụng quá mức phân bón hóa học và ô nhiễm do thuốc bảo vệ thực vật và hệ sinh thái đồng ruộng dần được phục hồi.

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

Tesis por compendio / Delottococcus aberiae (Hemiptera: Pseudococcidae) es un pseudocóccido invasor originario del África subsahariana que fue detectado causando graves daños en cítricos del este de España en el año 2009. Debido al desconocimiento existente sobre esta especie, la gestión de D. aberiae se ha llevado a cabo mediante el uso de tratamientos químicos autorizados contra este tipo de insectos. Sin embargo, la última Directiva Europea (2009/128/EC) sobre el uso sostenible de productos fitosanitarios estipula que la aplicación de plaguicidas en el ámbito agrícola debe reducirse, promoviendo estrategias de manejo más sostenibles como es la aplicación del control biológico de plagas. Además, cuando una especie invasora llega por primera vez a un territorio es necesario estudiar su biología, comportamiento, daños causados y posibilidades de control. En esta tesis se presentan por primera vez estos estudios de biología y comportamiento de la plaga así como un análisis de los daños producidos por D. aberiae. También se han realizado estudios con el objetivo de implementar la aplicación de un programa de control biológico clásico sobre esta especie en cítricos en España. Para analizar la biología y comportamiento de D. aberiae se han muestreado durante tres años varias parcelas de cítricos con poblaciones de D. aberiae en la Comunidad Valenciana. En estas parcelas se han recogido muestras y contabilizado todos los pseudocóccidos presentes, su estadío de desarrollo y el estrato y órgano del árbol donde se encontraban. El periodo de daños al fruto fue estudiado en semicampo y campo mediante la infestación artificial con D. aberiae de frutos de distintos tamaños de diámetro. Por último se estudió el comportamiento y las posibilidades de control biológico de D. aberiae muestreando diversas parcelas de cítricos en su zona de origen (Sudáfrica). Los resultados mostraron que la abundancia de las poblaciones de D. aberiae en cítricos es elevada en primavera y verano, reduciéndose a niveles mucho más bajos en otoño e invierno. Además el insecto completa varias generaciones a lo largo del año, estando dos de ellas muy claramente definidas y siendo las que dan lugar a elevadas poblaciones de la plaga. En cuanto a su distribución, D. aberiae se instaló principalmente en la copa del árbol y se observaron migraciones entre los distintos órganos, mostrando una clara preferencia por el fruto en desarrollo. Entre febrero y septiembre parte de las poblaciones de D. aberiae se encontraron en tronco y suelo, existiendo movimientos de subida y de bajada a la copa en función de la fenología de la planta y las condiciones climáticas. La comparativa entre técnicas de muestreo reveló que las trampas de cartón corrugado proporcionan una medida cuantitativa de la abundancia de D. aberiae en las parcelas. Por su parte, las trampas pegajosas, provistas de hembras de D. aberiae, fueron capaces de detectar los principales vuelos de machos. Por otro lado, D. aberiae causó daños directos al fruto (deformación y/o reducción de tamaño) al alimentarse del ovario de la flor o de los primeros estados de desarrollo de éste. Estos daños son posiblemente debidos a su interferencia con el proceso de división celular. Por último, en Sudáfrica, lugar de origen de la plaga, los mayores niveles poblaciones de D. aberiae se encontraron en verano y la tasa de parasitismo fue máxima en otoño. Entre el complejo de enemigos naturales de D. aberiae encontrados destacaron dos especies, Anagyrus sp. nov. 1 (Hymenoptera: Encyrtidae) y Allotropa sp. nov. (Hymenoptera: Platygastridae). Ambos parasitoides podrían tener un papel importante en un programa de control biológico contra D. aberiae en España. Por ahora, Anagyrus sp. nov. 1 parece el mejor candidato por sus mayores tasas de parasitismo en Sudáfrica. / Delottococcus aberiae (Hemiptera: Pseudococcidae) is an invasive mealybug native to sub-Saharan Africa that was detected causing significant damage to citrus fruits in eastern Spain in 2009. Due to the lack of knowledge about this species, the management of D. aberiae has been carried out by the application of authorized insecticides against mealybugs. However, the latest European Directive (2009/128 / EC) on the sustainable use of pesticides stipulates that chemical treatments in agroecosystems must be reduced, promoting more sustainable management strategies such as the application of biological control methodologies. In addition, when an invasive species arrives for the first time in a territory it is necessary to study its biology, behavior, damage caused and control possibilities. This thesis presents for the first time these studies of biology and behavior of the pest as well as a characterization of the damage produced by D. aberiae. The possibilities of implementing a classical biological control program against this species in citrus in Spain have also been studied. To analyze the biology and behavior of D. aberiae, several citrus orchards infested with the mealybug have been sampled for three years in the Valencian Community (eastern Spain). Samples have been collected periodically and the number of mealybugs, their developmental stage as well as the infested stratum and organ where they were present have being recorded. The period of damage to the fruit was studied in semi-field and field conditions by the artificial infestation with D. aberiae of fruits of different diameter. Finally, the behavior and possibilities of biological control of D. aberiae were studied by sampling several citrus orchards in the native area of the mealybug (South Africa). Results showed that the density of D. aberiae populations in citrus orchards is high in spring and summer, decreasing to lower levels in autumn and winter. In addition, the insect completes several generations throughout the year and two of them are clearly defined and result in high population levels. Regarding its distribution, D. aberiae was mostly installed in the canopy of the tree and migrations were observed between different organs, showing a clear preference for the developing fruit. From February to September some mealybugs were found in the trunk and soil, moving upwards or downwards depending on the phenology of the plant and the climatic conditions. The comparison between sampling techniques revealed that corrugated cardboard band traps provide a quantitative measurement of D. aberiae density in the orchards. On the other hand, sticky traps, baited with D. aberiae females were able to detect the main male flight periods. D. aberiae caused direct damage to the fruit (deformation and/or reduction in size) by feeding on the ovary of the flower or on small fruits in development. These damages are probably due to their interference with the process of cell division. Finally, in South Africa, native area of the pest, the highest density levels of D. aberiae were found in summer and the highest parasitism rates occurred in autumn. Among the complex of D. aberiae natural enemies, the two most abundant species were Anagyrus sp. nov. 1 (Hymenoptera: Encyrtidae) and Allotropa sp. nov. (Hymenoptera: Platygastridae). Both parasitoids could play an important role in a biological control program against D. aberiae in Spain. For now, Anagyrus sp. nov. 1 seems the best candidate because of its higher rates of parasitism in South Africa. / Delottococcus aberiae (Hemiptera: Pseudococcidae) és un pseudocòccid invasor originari de l'Àfrica subsahariana que va ser detectat causant greus danys en cítrics de l'est d'Espanya l'any 2009. A causa del desconeixement existent sobre aquesta espècie, la gestió de D. aberiae s'ha dut a terme mitjançant l'ús de tractaments químics autoritzats contra aquest tipus d'insectes. No obstant això, l'última Directiva Europea (2009/128/EC) sobre l'ús sostenible de productes fitosanitaris estipula que l'aplicació de plaguicides en l'àmbit agrícola ha de reduir-se, promovent estratègies de maneig més sostenibles com és l'aplicació del control biològic de plagues. A més, quan una espècie invasora arriba per primera vegada a un territori és necessari estudiar la seua biologia, comportament, danys causats i possibilitats de control. En aquesta tesi es presenten per primera vegada els estudis de biologia i comportament de la plaga així com una anàlisi dels danys produïts per D. aberiae. També s'han realitzat estudis amb l'objectiu d'implementar l'aplicació d'un programa de control biològic clàssic sobre aquesta espècie en cítrics a Espanya. Per a analitzar la biologia i comportament de D. aberiae s'han mostrejat durant tres anys diverses parcel·les de cítrics amb poblacions de D. aberiae a la Comunitat Valenciana. En aquestes parcel·les s'han recollit mostres i comptabilitzat tots els pseudocòccids presents, el seu estadi de desenvolupament i l'estrat i òrgan de l'arbre on es trobaven. El període de danys al fruit va ser estudiat en semicamp i camp mitjançant la infestació artificial amb D. aberiae de fruits de diferents mides de diàmetre. Finalment es va estudiar el comportament i les possibilitats de control biològic de D. aberiae mostrejant diverses parcel·les de cítrics en la seua zona d'origen (Sud-àfrica). Els resultats van mostrar que l'abundància de les poblacions de D. aberiae en cítrics és elevada a la primavera i estiu, reduint-se a nivells molt més baixos a la tardor i hivern. A més l'insecte completa diverses generacions al llarg de l'any, estant dos d'elles molt clarament definides i sent les que donen lloc a elevades poblacions de la plaga. Quant a la seua distribució, D. aberiae es va instal·lar principalment en la copa de l'arbre i es van observar migracions entre els diferents òrgans, mostrant una clara preferència pel fruit en desenvolupament. Entre febrer i setembre part de les poblacions de D. aberiae es van trobar en tronc i sòl, existint moviments de pujada i de baixada a la copa en funció de la fenología de la planta i les condicions climàtiques. La comparativa entre tècniques de mostreig va revelar que les trampes de cartró corrugat proporcionen una mesura quantitativa de l'abundància de D. aberiae en les parcel·les. Per la seua banda, les trampes apegaloses proveïdes de femelles de D. aberiae van aconseguir detectar els principals vols de mascles. D'altra banda, D. aberiae va causar danys directes al fruit (deformació i/o reducció de mida) en l'alimentar-se de l'ovari de la flor o dels primers estats de desenvolupament d'aquest. Aquest danys són possiblement deguts a la seua interferència amb el procés de divisió cel·lular. Finalment, a Sud-àfrica, lloc d'origen de la plaga, els majors nivells poblacionals de D. aberiae es van trobar a l'estiu i la taxa de parasitisme va ser màxima a la tardor. Entre el complex d'enemics naturals de D. aberiae trobats van destacar dues espècies, Anagyrus sp. nov. 1 (Hymenoptera: Encyrtidae) i Allotropa sp. nov. (Hymenoptera: Platygastridae). Tots dos parasitoides podrien tindre un paper important en un programa de control biològic contra D. aberiae a Espanya. Per ara, Anagyrus sp. nov. 1 sembla el millor candidat per les seues majors taxes de parasitisme a Sud-àfrica. / Martínez Blay, V. (2018). Biology and management, by application of classical biological control, of the invasive mealybug Delotoccoccus aberiae (Hemiptera:Pseudococcidae) in citrus orchards in Spain [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/106363 / Compendio

<p dir="ltr">The striped cucumber beetle (<i>Acalymma vittatum</i>) is a leading pest across a variety of cucurbit crops in eastern North America. These beetles can rapidly infest and damage a field, leading to frequent insecticide applications to manage them. Chemical control is effective at reducing beetle populations, but it also causes detrimental non-target effects on pollinators, which are essential for cucurbit yield. Developing a holistic IPM (integrated pest management) approach is necessary to manage pests while avoiding non-target effects in cucurbit production systems. </p><p dir="ltr">A unique and well-characterized behavior of striped cucumber beetles is their olfactory attraction to both plant volatiles and their species-specific aggregation pheromone, vittatalactone. The interacting effects of combining these olfactory stimuli for cucumber beetle attraction have not previously been tested. I expected when presented with plant volatiles and pheromone together, the striped cucumber beetles will show synergistic attraction, resulting in enhanced attraction stronger than the sums of the separate effects. Along with targeting striped cucumber beetles, I expected to elicit cross-attraction of related cucurbit pests (e.g., spotted cucumber beetle) to these same signals based on previous findings indicating cross-attraction. The expected cross attraction may be due to the reliance on olfactory cues to inform the related insects on preferrable host plants and nutrition. </p><p dir="ltr">Cucurbit systems are also highly reliant on pollination services for high-quality fruit; thus, the feasibility of these semiochemical tools depends on their influence on pollinator behavior. I expect pollinators to be attracted to floral volatiles but not vittatalactone or individual plant volatiles without the full complement of floral scent (e.g., indole, leaf volatiles). Altogether, this research aims to develop a targeted management tool for striped cucumber beetles and other cucurbit pests, while avoiding pollinator distraction or other detrimental effects.</p><p dir="ltr">To measure the efficacy of using olfactory signals as attractants, clear sticky cards were deployed in the field with combinations of pheromone paired with volatiles (floral and/or leaf), as well as the individual components, to quantify pest responses. Simultaneously, a pan trap sampling method was implemented to measure pollinator responses to the same semiochemical combinations. The results of the study demonstrate that striped cucumber beetles are strongly attracted to volatile lures containing pheromones, floral volatiles, and combinations of the two, although the combined pheromone and floral volatile treatments did not synergize beetle attraction. </p><p dir="ltr">Though combined lures did not synergize attraction, this data demonstrates additive effects on beetle behavior. The findings also highlight the importance of understanding seasonal disparities between the behavior of early and late generations of striped cucumber beetles. Temporal variation in attraction demonstrated by the pests is crucial to understand when to implement lure-based management strategies. Two years of testing floral volatile and herbivory-induced plant volatile (HIPV) lure treatments on key cucurbit pollinators showed varying levels of attraction. There was no attraction of focal cucurbit bees to the striped cucumber beetle pheromone, but there were differences in the response of pollinators to plant volatile components. </p><p dir="ltr">Cucurbits require high pollination activity for successful fruit, though the most important bees in pollinating this system are bees belonging to the genera, <i>Apis</i> and <i>Eucera</i>. Along with these bee groups, other bees such as those belonging to <i>Melissodes</i>, <i>Lasioglossum</i>, and <i>Bombus</i> are also known important pollinators. <i>Lasioglossum</i> bees showed a strong attraction to the full-floral blend, TIC (1,2,4-trimethoxybenzene, indole, (E)-cinnamaldehyde), but no preference for indole or HIPVs. <i>Melissodes</i> bees were most attracted to methyl salicylate and TIC, whereas <i>Eucera</i> bees exhibited strong attraction to ocimene and TIC. These findings suggest that different pollinator taxa have unique preferences for plant volatiles, highlighting the importance of optimizing lure combinations to avoid disrupting pollination activities in cucurbit production.</p><p dir="ltr">Additionally, this study revealed that other key cucurbit pests, such as spotted cucumber beetles and western corn rootworms, also showed strong attraction to the tested volatile components. These findings suggest that the selected volatiles may have broader implications for pest management beyond striped cucumber beetles. Further research is needed to fully understand the efficacy and refine formulations of these volatile lures to implement in IPM.</p>

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (obscure mealybug), is a common and serious pest of apples and pears in South Africa. Consumer and regulatory pressure to produce commodities under sustainable and ecologically compatible conditions has rendered chemical control options increasingly limited. Information on the seasonal occurrence of pests is but one of the vital components of an effective and sustainable integrated pest management system needed for planning the initiation of monitoring and determining when damage can be expected. It is also important to identify which orchards are at risk of developing mealybug infestations while development of effective and early monitoring tools for mealybug populations will help growers in making decisions with regards to pest management and crop suitability for various markets. It is also essential to determine the presence and efficacy of naturally occurring biological control agents in orchards so as to ascertain the potential of biological control as a viable alternative in orchards. However, under the current integrated pest management protocol, it has been difficult to determine this, due to the sporadic and relatively low incidence of mealybug infestations in some orchards, or by simply relying on naturally occurring field populations of biocontrol agents. Knowledge of the environmental conditions under which P. viburni population levels may become destructive is also essential for timing the release of insectary reared natural enemies as well as understanding the population ecology of this pest and its natural enemies. Information was gathered regarding the seasonal phenology of P. viburni and its natural enemies in pome fruit orchards in the Western Cape Province during the 2007/08 and 2008/09 growing seasons. Seasonal population studies showed that P. viburni has multiple overlapping generations with all life stages present throughout the year. The highest orchard infestations occurred during the summer period until early winter (January to early June). This was followed by a decrease in population from late June to November, before another increase in December. Presence-absence sampling of mealybugs on the host plant revealed that woody parts of the tree, such as the trunk and old stems were the most preferred sites for mealybug habitation, due to the availability of protected refuge sites. Migration of mealybug populations to newer growth and the upper sections of the tree crown, such as the new stems, leaves and eventually the fruit, was observed from December throughout the summer period until the early winter in June. Fruit colonization in both apples and pears commenced in January, when the fruit had developed a size sufficient for P. viburni to penetrate and occupy spaces such as the fruit core, calyx and stem end. There was no evidence of P. viburni occurring beneath the soil surface or on the roots of host trees. Two natural enemies of mealybugs, namely Pseudaphycus maculipennis (Mercet) and Coccidoxenoides perminutus (Girault), were found to be active in apple and pear orchards in the Western Cape. However, the status of C. perminutus as a parasite of P. viburni still needs to be verified despite evidence of emergence from P. viburni mummies, which was not sufficient enough to suggest that it is a useful biological control agent. Seasonal abundance trends of the two natural enemies revealed that their lifecycle is synchronized with that of the host. However, there was no evidence of P. maculipennis activity in Ceres. No predators were found during the course of this study. The rate of P. viburni parasitism at harvest was 46.52%, with P. maculipennis and C. perminutus constituting 98.966% and 1.034% of the parasitoids recovered from mealybug mummies, respectively. Studies on the use of pheromone traps as early monitoring tools for P. viburni showed that there was a positive and significant relationship between the fruit infestation and number of P. viburni adult males caught in pheromone-baited traps (r2 = 0.454). The action threshold level was estimated to be 2.5 male P. viburni caught per trap per fortnight at an economic threshold of 2% fruit infestation. / AFRIKAANSE OPSOMMING: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (ligrooswitluis), is ‘n algemene en ernstige plaag van appels en pere in Suid-Afrika. Druk deur verbruikers en regulasies om kommoditeite onder volhoubare en ekologies verenigbare toestande te produseer het chemiese beheeropsies toenemend beperk. Inligting oor die seisoenale voorkoms van plae is een van die essensiële komponente van ‘n effektiewe en volhoubare geïntegreerde plaagbestuurprogram. Dit is in die aanvanklike beplanning van monitering en om te bepaal wanneer skade verwag kan word. Dit is ook belangrik om boorde vroegtydig te identifiseer wat die risiko het om witluisbesmettings te ontwikkel. Die ontwikkeling van effektiewe en vroeë moniteringstegnieke vir witluisbevolkings sal produsente help met besluitneming rakende plaagbestuur en die geskiktheid van gewasse vir verskeie markte. Dit is ook noodsaaklik om die teenwoordigheid en effektiwiteit van biologiese beheer agente wat natuurlik in boorde voorkom te bepaal ten einde die potensiaal van biologiese beheer as ‘n lewensvatbare alternatief vas te stel. Onder die huidige geïntegreerde plaagbestuurprotokol was dit egter moeilik om laasgenoemde te bepaal weens die sporadiese en relatiewe lae voorkoms van witluisbesmettings in sommige boorde of deur bloot staat te maak op die veldpopulasies van biologiese beheer agente wat natuurlik voorkom. Kennis van die omgewingstoestande waaronder P. viburni bevolkingsvlakke skadelik raak is ook noodsaaklik vir die beplanning van vrylating van biologiese beheer agente, asook om die bevolkingsekologie van hierdie plaag en sy natuurlike vyande te verstaan. Inligting oor die seisoenale fenologie van P. viburni en sy natuurlike vyande in sagtevrugte boorde in die Westelike Kaapprovinsie is gedurende die 2007/08 en 2008/09 groeiseisoene versamel. Seisoenale bevolkingstudies het getoon dat P. viburni verskeie oorvleuelende generasies het met alle stadia teenwoordig regdeur die jaar.