Search

The current whitefly invasion is becoming a growing threat to coconut palms in Sri Lanka and will severely influence coconut production in the country. To effectively manage this problem, it is crucial toidentify the specific species that have invaded the coconut palms in the country to accordingly provide appropriate solutions. The taxonomy of the whitefly is mainly based on the characters of the pupae. Thus, a field survey was conducted in 2023 to identify the key whitefly species that invaded the coconut palms and their host range in Sri Lanka. The colonies of infested whiteflies were collected from coconut palms in different coconut-growing areas of Sri Lanka, and the pupae were slide-mounted and identified up to species level using taxonomic keys. Further, diagnostic characters of each species and host range were documented. The whitefly species found on the coconut palms (Cocos nucifera) were identified as Aleurodicus rugioperculatus, Aleurodicus dispersus, and Aleurotrachelus atratus. A. atratus was discovered only from the C. nucifera. A. dispersus and A. rugioperculatus were reported from 5 and 24 host plant species including the coconut from 5 and 18 different families respectively.

The current whitefly invasion is becoming a growing threat to coconut palms in Sri Lanka and will severely influence coconut production in the country. To effectively manage this problem, it is crucial toidentify the specific species that have invaded the coconut palms in the country to accordingly provide appropriate solutions. The taxonomy of the whitefly is mainly based on the characters of the pupae. Thus, a field survey was conducted in 2023 to identify the key whitefly species that invaded the coconut palms and their host range in Sri Lanka. The colonies of infested whiteflies were collected from coconut palms in different coconut-growing areas of Sri Lanka, and the pupae were slide-mounted and identified up to species level using taxonomic keys. Further, diagnostic characters of each species and host range were documented. The whitefly species found on the coconut palms (Cocos nucifera) were identified as Aleurodicus rugioperculatus, Aleurodicus dispersus, and Aleurotrachelus atratus. A. atratus was discovered only from the C. nucifera. A. dispersus and A. rugioperculatus were reported from 5 and 24 host plant species including the coconut from 5 and 18 different families respectively.

The current whitefly invasion is becoming a growing threat to coconut palms in Sri Lanka and will severely influence coconut production in the country. To effectively manage this problem, it is crucial toidentify the specific species that have invaded the coconut palms in the country to accordingly provide appropriate solutions. The taxonomy of the whitefly is mainly based on the characters of the pupae. Thus, a field survey was conducted in 2023 to identify the key whitefly species that invaded the coconut palms and their host range in Sri Lanka. The colonies of infested whiteflies were collected from coconut palms in different coconut-growing areas of Sri Lanka, and the pupae were slide-mounted and identified up to species level using taxonomic keys. Further, diagnostic characters of each species and host range were documented. The whitefly species found on the coconut palms (Cocos nucifera) were identified as Aleurodicus rugioperculatus, Aleurodicus dispersus, and Aleurotrachelus atratus. A. atratus was discovered only from the C. nucifera. A. dispersus and A. rugioperculatus were reported from 5 and 24 host plant species including the coconut from 5 and 18 different families respectively.

Sap-sucking insects, including whiteflies, are amongst the most devastating and widely distributed organisms on the planet. They are often highly invasive and endosymbiont communities within these insects help them adapt to new or changing environments. Bemisia tabaci (Gennadius; Hemiptera: Aleyrodidae) whitefly species are vectors of more than 500 known plant-viruses and harbour highly diverse endosymbionts communities. To date, however, whitefly–endosymbiont interactions, community structure and their spatio-temporal changes are still poorly understood. In this study, we investigated the spatio-temporal changes in the composition and diversity of bacterial endosymbionts in the agricultural crop pest whitefly species, Bemisia tabaci sub-Saharan Africa 1-subgroup 1 and 2 (SSA1-SG1 and SSA1-SG2). 16S rRNA amplicon sequencing analysis was carried out to characterise endosymbiont compositionsin field-collected SSA1 (SSA1-SG1 and SSA1-SG2) populations infesting cassava in Uganda in 1997 and 2017. We detected Portiera, Arsenophonus, Wolbachia, Hamiltonella and Hemipteriphilus, with Arsenophonus and Wolbachia infections being predominant. Hemipteriphilus and Hamiltonella frequencies were very low and were detected in seven and two samples, respectively. Bacterial diversity based on three independent parameters including Simpson index, number of haplotypes and Bray–Curtis dissimilarity matrix was significantly higher in 1997 than in 2017. This period also coincided with the advent of super-abundant cassava-whitefly populations on cassava crops in Uganda. We discuss how endosymbionts may influence the biology and behaviour of whiteflies leading to population explosions.

The invasion success of a species in an agrosystem is greatly influenced by environmental factors such as the use of insecticides, by the intrinsic evolutionary capabilities of the species, and also by interactions with resident species. On the island of La Réunion, the successive invasions of MEAM1 and MED whitefly species over the last 20 years have not only led an increased use of insecticides, but have also challenged the resident IO species. To trace the evolution of the 3 species, and the distribution of the kdr mutation (resistance to pyrethroid) in the para-type voltage-gated sodium channel, we genotyped 41 populations (using neutral nuclear markers) and look at the prevalence of the kdr allele. MEAM1 was predominantly present in agrosystems showing quasi fixation of the resistant kdr allele whereas IO was mainly in natural environments and did not have any resistant allele. Hybridization between the two former species was detected in low frequency but has not led to introgression of resistant alleles in the resident species so far. MED showed a limited distribution in agrosystems but all individuals displayed a resistant allele. These highly contrasting patterns of distribution and resistant mutations between invasive and resident whitefly species are further discussed.

Cassava crops hold high agricultural importance in Paraná State, Brazil. However, cassava root production is adversely impacted by pests. Aleyrodids, in particular, cause great damage to cassava fields, necessitating better knowledge of predators found in these agroecosystems and novel biological control strategies for integrated pest management. This study reports the first occurrence of the predatory lady beetle Delphastus argentinicus Nunenmacher, preying on all life stages of whiteflies in cassava fields. Given the economic and social importance of cassava crops in Brazil and the deleterious potential of aleyrodid species, it is recommended to conduct behavioral and bioecological studies assessing the application of D. argentinicus as a biocontrol agent in integrated pest management programs.

In this study, potential banker plant systems against the cabbage whitefly Aleyrodes proletella Linnaeus (Hemiptera: Aleyrodidae) were developed under controlled conditions. The two most promising banker plant systems, that is, the parasitoid Encarsia tricolor Förster (Hymenoptera: Aphelinidae) either with Aleyrodes lonicerae Walker on European columbine (columbine system) or with Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) on Hokkaido squash (pumpkin system), were further evaluated in the field. Although the pumpkin system produced three times more parasitoids than the columbine system, both banker plants led to an 1.5-fold increase in A. proletella parasitism rates. However, only the pumpkin system increased the abundance of syrphid larvae on cabbage by 61.5% and reduced A. proletella populations on average by 4.4%–25.8% depending on the respective assessment date. In conclusion, the pumpkin system revealed to be a promising (supplementary) control measure against A. proletella. Options for further improvement and standardization of the pumpkin system as well as a potential implementation in cabbage production are discussed. © 2020 The Authors. Journal of Applied Entomology published by Wiley-VCH GmbH

The cabbage whitefly Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae) is an important pest of a wide range of vegetable Brassicas. Since the control of this pest is still challenging, new approaches such as the use of resistant cultivars are required. For this, we screened 16 commercialised Brussels sprout cultivars for resistance against this species. Antibiosis was tested with no-choice experiments in a climate chamber, using reproduction, mortality, longevity, developmental time and weight as parameters. Antixenosis was screened in three choice experiments with circular design in a greenhouse to detect cultivar preferences. A field trial with both antibiosis and antixenosis tests was done to verify results under natural conditions. Finally, for several cultivars, also the leaf glucosinolate concentrations were analysed. Cabbage whiteflies showed on certain cultivars significantly increased mortality, prolonged developmental times and reduced weights. Besides, some cultivars were significantly less infested. However, the incidence of antibiosis and antixenosis as well as the glucosinolate patterns were partly inconsistent. Although a number of moderately resistant cultivars could be identified, the detected resistance is certainly not strong and consistent enough as an exclusive measure of a plant protection strategy but might become a component of a multi-layered strategy against cabbage whiteflies.

Invasive species are a leading and growing threat to our nation's agricultural and natural resources. Thousands of exotic species have been introduced into the U.S., and the estimated damage and management costs of invasive species exceed $138 billion per year. In response to this threat, the Utah Plant Pest Diagnostic Lab (UPPDL) and Utah State University (USU) Extension created the Utah First Detector Program to prepare citizen responders with the knowledge and skills necessary to identify invasive insects, collect and submit high quality samples to the UPPDL, and notify the appropriate authorities when necessary. The UPPDL and USU Extension work closely with other federal and state agencies, such as the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine (USDA APHIS PPQ) Program, USDA Forest Service, and Utah Department of Agriculture and Food (UDAF), to address invasive pest threats. The Utah First Detector Program is, in part, an extension of the Utah Cooperative Agricultural Pest Survey (CAPS) Program, which is part of the larger national CAPS program. For more information about the Utah CAPS program, visit http://utahpests.usu.edu/caps. The target audience for the Utah First Detector Program includes Master Gardeners, Extension personnel, state agricultural inspectors, certified arborists, tree and lawncare professionals, forestry and natural resource professionals, conservationists, and others with an interest in pest detection and response.

Studies confirming adaptive sex allocation, or a flexible relative investment in males and females, have been extensive in Hymenoptera, and have been used to predict the quality of biological control agents, to theorize how eusociality is maintained, and to predict population dynamics. Most hymenopterans are haplodiploid, in which females are derived from fertilized eggs and males from unfertilized eggs, so haplodiploid mothers may have a greater ability to adaptively adjust sex allocation. Thysanoptera and Aleyrodidae are also haplodiploid organisms, many of them being important agricultural pests, but less comprehensive studies on sex allocation have been performed with these taxa. Both taxa are also mostly herbivorous, drawing in new elements that may affect sex allocation patterns. This review is a summary of all studies of Aleyrodidae and Thysanoptera sex ratios as affected by temperature, host plant and nutrition, conspecifics, competitors, bacterial and viral endosymbionts, predators, parasitoids and other pathogens. Sex ratio influences were found in studies testing effects of temperature, host plant, conspecifics, competitors, bacterial endosymbionts and a fungal pathogen. Viruses, predators and parasitoids were not found to affect sex ratios in Aleyrodidae and Thysanoptera, although not many studies have collected the data to assess these potential factors. Because sex ratio studies in Thysanoptera and Aleyrodidae have only recorded secondary, adult or operational sex ratios instead of primary sex ratios, differential developmental mortality is left as a confounding variable, and it is difficult to determine whether sex ratio changes are due to sex allocation. To conclude whether sex allocation of mothers is taking place, the primary sex ratios need to be recorded, so we have also included methods for tools, including cytogenetics and survival assays, to find primary sex ratios or confirm differential developmental mortality in these haplodiploid organisms

Despite being a polyphagous insect, Bemisia tabaci (Gennadius) shows a marked preference for certain hosts, which in turn may depend upon the particular whitefly biotype involved. The objective of this research was to compare preference towards a selected group of host crops, by two biotypes of Bemisia tabaci, New World in Costa Rica, and MEAM1 in Florida. Therefore, choice experiments were conducted in greenhouses both at Turrialba (Costa Rica) and Immokalee (Florida), in April and June-September, 1998, respectively. The same crops and varieties were exposed to the New World and MEAM1 biotypes, which predominate in each one of these locations, respectively. Host species included green beans (Phaseolus vulgaris), bell pepper (Capsicum annuum), eggplant (Solanum melongena), cucumber (Cucumis sativus), tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). Seedlings were transplanted in large pots, which were distributed on the greenhouse floor. B. tabaci adults were released in the late afternoon, and the number of individuals on each plant was recorded the next morning. In Turrialba, tobacco was greatly preferred by New World biotype adults, followed by eggplant, whereas the MEAM1 biotype in Florida preferred green beans and eggplant. Thus, both biotypes showed a strong and significant preference for eggplant, which suggests its possible utility as a trap crop., Bemisia tabaci (Gennadius) muestra una gran polifagia, pero también una marcada preferencia por ciertos hospedantes, lo cual puede depender del biotipo específico involucrado. El objetivo de la presente investigación fue comparar la preferencia hacia un grupo selecto de cultivos hospedantes, por parte de dos biotipos de Bemisia tabaci, el New World en Costa Rica, y el MEAM1 en Florida. Para ello, se realizaron experimentos de preferencia, en invernaderos, tanto en Turrialba (Costa Rica) como en Immokalee (Florida), en abril y junio-setiembre de 1998, respectivamente. Se expusieron los mismos cultivos y variedades a los biotipos New World y MEAM1, predominantes en cada una de esas localidades, respectivamente. Se incluyeron la vainica (Phaseolus vulgaris), el chile dulce (Capsicum annuum), la berenjena (Solanum melongena), el pepino (Cucumis sativus), el tabaco (Nicotiana tabacum) y el tomate (Solanum lycopersicum). Los potes con plántulas de cada uno de los hospedantes se colocaron sobre el piso del invernadero, espaciados entre sí. Se liberaron los adultos de B. tabaci en el área experimental, y después se registraron los números de individuos en cada planta. En Turrialba el tabaco fue el cultivo preferido por el biotipo New World, seguido por la berenjena, mientras que en Florida el biotipo MEAM1 prefirió la vainica y la berenjena. No obstante, a pesar de estas diferencias, ambos biotipos exhibieron una fuerte y significativa preferencia por la berenjena, lo cual abre la posibilidad para su utilización como cultivo trampa.

Despite being a polyphagous insect, Bemisia tabaci (Gennadius) shows a marked preference for certain hosts, which in turn may depend upon the particular whitefly biotype involved. The objective of this research was to compare preference towards a selected group of host crops, by two biotypes of Bemisia tabaci, New World in Costa Rica, and MEAM1 in Florida. Therefore, choice experiments were conducted in greenhouses both at Turrialba (Costa Rica) and Immokalee (Florida), in April and June-September, 1998, respectively. The same crops and varieties were exposed to the New World and MEAM1 biotypes, which predominate in each one of these locations, respectively. Host species included green beans (Phaseolus vulgaris), bell pepper (Capsicum annuum), eggplant (Solanum melongena), cucumber (Cucumis sativus), tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). Seedlings were transplanted in large pots, which were distributed on the greenhouse floor. B. tabaci adults were released in the late afternoon, and the number of individuals on each plant was recorded the next morning. In Turrialba, tobacco was greatly preferred by New World biotype adults, followed by eggplant, whereas the MEAM1 biotype in Florida preferred green beans and eggplant. Thus, both biotypes showed a strong and significant preference for eggplant, which suggests its possible utility as a trap crop., Bemisia tabaci (Gennadius) muestra una gran polifagia, pero también una marcada preferencia por ciertos hospedantes, lo cual puede depender del biotipo específico involucrado. El objetivo de la presente investigación fue comparar la preferencia hacia un grupo selecto de cultivos hospedantes, por parte de dos biotipos de Bemisia tabaci, el New World en Costa Rica, y el MEAM1 en Florida. Para ello, se realizaron experimentos de preferencia, en invernaderos, tanto en Turrialba (Costa Rica) como en Immokalee (Florida), en abril y junio-setiembre de 1998, respectivamente. Se expusieron los mismos cultivos y variedades a los biotipos New World y MEAM1, predominantes en cada una de esas localidades, respectivamente. Se incluyeron la vainica (Phaseolus vulgaris), el chile dulce (Capsicum annuum), la berenjena (Solanum melongena), el pepino (Cucumis sativus), el tabaco (Nicotiana tabacum) y el tomate (Solanum lycopersicum). Los potes con plántulas de cada uno de los hospedantes se colocaron sobre el piso del invernadero, espaciados entre sí. Se liberaron los adultos de B. tabaci en el área experimental, y después se registraron los números de individuos en cada planta. En Turrialba el tabaco fue el cultivo preferido por el biotipo New World, seguido por la berenjena, mientras que en Florida el biotipo MEAM1 prefirió la vainica y la berenjena. No obstante, a pesar de estas diferencias, ambos biotipos exhibieron una fuerte y significativa preferencia por la berenjena, lo cual abre la posibilidad para su utilización como cultivo trampa.

Studies confirming adaptive sex allocation, or a flexible relative investment in males and females, have been extensive in Hymenoptera, and have been used to predict the quality of biological control agents, to theorize how eusociality is maintained, and to predict population dynamics. Most hymenopterans are haplodiploid, in which females are derived from fertilized eggs and males from unfertilized eggs, so haplodiploid mothers may have a greater ability to adaptively adjust sex allocation. Thysanoptera and Aleyrodidae are also haplodiploid organisms, many of them being important agricultural pests, but less comprehensive studies on sex allocation have been performed with these taxa. Both taxa are also mostly herbivorous, drawing in new elements that may affect sex allocation patterns. This review is a summary of all studies of Aleyrodidae and Thysanoptera sex ratios as affected by temperature, host plant and nutrition, conspecifics, competitors, bacterial and viral endosymbionts, predators, parasitoids and other pathogens. Sex ratio influences were found in studies testing effects of temperature, host plant, conspecifics, competitors, bacterial endosymbionts and a fungal pathogen. Viruses, predators and parasitoids were not found to affect sex ratios in Aleyrodidae and Thysanoptera, although not many studies have collected the data to assess these potential factors. Because sex ratio studies in Thysanoptera and Aleyrodidae have only recorded secondary, adult or operational sex ratios instead of primary sex ratios, differential developmental mortality is left as a confounding variable, and it is difficult to determine whether sex ratio changes are due to sex allocation. To conclude whether sex allocation of mothers is taking place, the primary sex ratios need to be recorded, so we have also included methods for tools, including cytogenetics and survival assays, to find primary sex ratios or confirm differential developmental mortality in these haplodiploid organisms

The aim of this study was to characterize the spatial distribution of citrus black fly (Aleurocanthus woglumi) in citrus orchard in agroforestry plantation in Pará State, Brazil. The experimental area is located in Capitão Poço, Northeastern Pará. Twelve samples were taken monthly where the presence or absence of the pest in the experimental area were evaluated. From each sampling point (plant) we obtained the value of the variable and the coordinates (latitude and longitude). By the parameters of semivariogram models the surveys were interpolated by kriging method which provided us spatial distribution maps of the areas of higher and lower infestation of the black fly. The results showed that the spatial distribution of black fly takes place predominantly in clusters with spatial dependence described by the spherical model, forming clusters from 15.5 to 34 m (range of the model)., O objetivo deste trabalho foi caracterizar a distribuição espacial da mosca-negra-dos-citros (Aleurocanthus woglumi) em pomar de citros em plantio agroflorestal no Estado do Pará. A área experimental está localizada no município de Capitão Poço, região nordeste do Estado do Pará, onde foram realizadas amostragens mensais, avaliando a presença ou ausência da praga na área experimental. De cada ponto de amostragem (planta) obteve-se o valor da variável e as coordenadas (latitude e longitude). Através dos parâmetros dos modelos do semivariograma, foram interpolados os levantamentos através da krigagem que nos forneceu mapas da distribuição espacial mostrando as áreas de maior e menor infestação de mosca negra. Os resultados mostram que a distribuição espacial da praga dá-se, predominantemente, em agrupamentos com dependência espacial descrita pelo modelo esférico, formando reboleiras de 15,5 a 34 m (alcance do modelo).

behavior as a potential target for novel monitoring and pest control tools. Yellow sticky traps have been commonly used for monitoring whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect whitefly capture. Therefore, the use of light-emitting diodes (LEDs) can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out to investigate the efficacy of LED-equipped yellow sticky traps in the capturing mechanism of adult whiteflies Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). This study has taken place in a little glass greenhouse at the Argentine Agricultural Experiment Station (EEA) of the National Institute for Agricultural Technology (INTA) of Concordia, Province of Entre Rios (Argentina), where rearing insect cages were placed together with tobacco plants, Solanum tabacum L. and beans Phaseolus vulgaris L. from June to July, 2013. The yellow sticky traps covered an area of 64 cm2 and were supplemented with LEDs of different wavelengths, namely, greenLEDs (525 nm) and UV LEDs (380 nm), in addition to a control treatment without LEDs. The trials showed that T. vaporariorum adults on average preferred (p>0.05) traps equipped with green LEDs (525nm) (134 ± 7.4 adults/trap) compared to traps equipped with UV LEDs (105 ± 7.4 adults/trap) and traps without LEDs (85.17 ± 7.4 adults/trap). The results show that T. vaporariorum adults are attracted to yellow sticky traps attached to green LEDs, which could have a promising use in greenhouses for the identification, monitoring, and control of whiteflies., Teniendo en cuenta que algunos adultos de insectos muestran preferencia a ciertas longitudes de onda, se ha considerado este comportamiento para desarrollar herramientas de monitoreo y estrategias de control de insectos plaga. Como ejemplo de ello, las tarjetas adhesivas amarillas han sido ampliamente usadas para monitorear población de moscas blancas a campo como invernadero. Este estudio tuvo como objetivo evaluar la efectividad de trampas adhesivas amarillas provistas con luces emitidas por diodos (LEDs) para el trampeo de adultos moscas blancas Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). Los ensayos se llevaron a cabo en la EEA INTA Concordia en condiciones de umbráculo, donde se ubicaron jaulas de cría con plantas de tabaco, Solanum tabacum (L.) y poroto, Phaseolus vulgaris L. desde Junio hasta Julio del 2013. Las trampas adhesivas amarillas tuvieron una superficie de 64cm2 provistas con (LEDs) de diferentes longitudes de onda promedio (525 nm verde y 380 nm UV) y sin LED como testigo. Los ensayos mostraron que los adultos de mosca blanca fueron significativamente (p >0,05) más atraídos por las trampas equipadas con LED 525nm verde (134 ± 7,4 adultos/tarjeta) comparadas con trampas equipadas con LED 380 nm UV (105 ± 7,4 adultos/tarjeta) y trampas sin LED (85,17 ± 7,4 adultos/tarjeta). Estos resultados muestran que los adultos de T. vaporariorum son atraídos a trampas dotadas con LED verde, las cuales podrían tener un promisorio uso en invernadero como detección, monitoreo y control de mosca blanca.

The aim of this study was to characterize the spatial distribution of citrus black fly (Aleurocanthus woglumi) in citrus orchard in agroforestry plantation in Pará State, Brazil. The experimental area is located in Capitão Poço, Northeastern Pará. Twelve samples were taken monthly where the presence or absence of the pest in the experimental area were evaluated. From each sampling point (plant) we obtained the value of the variable and the coordinates (latitude and longitude). By the parameters of semivariogram models the surveys were interpolated by kriging method which provided us spatial distribution maps of the areas of higher and lower infestation of the black fly. The results showed that the spatial distribution of black fly takes place predominantly in clusters with spatial dependence described by the spherical model, forming clusters from 15.5 to 34 m (range of the model)., O objetivo deste trabalho foi caracterizar a distribuição espacial da mosca-negra-dos-citros (Aleurocanthus woglumi) em pomar de citros em plantio agroflorestal no Estado do Pará. A área experimental está localizada no município de Capitão Poço, região nordeste do Estado do Pará, onde foram realizadas amostragens mensais, avaliando a presença ou ausência da praga na área experimental. De cada ponto de amostragem (planta) obteve-se o valor da variável e as coordenadas (latitude e longitude). Através dos parâmetros dos modelos do semivariograma, foram interpolados os levantamentos através da krigagem que nos forneceu mapas da distribuição espacial mostrando as áreas de maior e menor infestação de mosca negra. Os resultados mostram que a distribuição espacial da praga dá-se, predominantemente, em agrupamentos com dependência espacial descrita pelo modelo esférico, formando reboleiras de 15,5 a 34 m (alcance do modelo).

behavior as a potential target for novel monitoring and pest control tools. Yellow sticky traps have been commonly used for monitoring whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect whitefly capture. Therefore, the use of light-emitting diodes (LEDs) can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out to investigate the efficacy of LED-equipped yellow sticky traps in the capturing mechanism of adult whiteflies Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). This study has taken place in a little glass greenhouse at the Argentine Agricultural Experiment Station (EEA) of the National Institute for Agricultural Technology (INTA) of Concordia, Province of Entre Rios (Argentina), where rearing insect cages were placed together with tobacco plants, Solanum tabacum L. and beans Phaseolus vulgaris L. from June to July, 2013. The yellow sticky traps covered an area of 64 cm2 and were supplemented with LEDs of different wavelengths, namely, greenLEDs (525 nm) and UV LEDs (380 nm), in addition to a control treatment without LEDs. The trials showed that T. vaporariorum adults on average preferred (p>0.05) traps equipped with green LEDs (525nm) (134 ± 7.4 adults/trap) compared to traps equipped with UV LEDs (105 ± 7.4 adults/trap) and traps without LEDs (85.17 ± 7.4 adults/trap). The results show that T. vaporariorum adults are attracted to yellow sticky traps attached to green LEDs, which could have a promising use in greenhouses for the identification, monitoring, and control of whiteflies., Teniendo en cuenta que algunos adultos de insectos muestran preferencia a ciertas longitudes de onda, se ha considerado este comportamiento para desarrollar herramientas de monitoreo y estrategias de control de insectos plaga. Como ejemplo de ello, las tarjetas adhesivas amarillas han sido ampliamente usadas para monitorear población de moscas blancas a campo como invernadero. Este estudio tuvo como objetivo evaluar la efectividad de trampas adhesivas amarillas provistas con luces emitidas por diodos (LEDs) para el trampeo de adultos moscas blancas Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). Los ensayos se llevaron a cabo en la EEA INTA Concordia en condiciones de umbráculo, donde se ubicaron jaulas de cría con plantas de tabaco, Solanum tabacum (L.) y poroto, Phaseolus vulgaris L. desde Junio hasta Julio del 2013. Las trampas adhesivas amarillas tuvieron una superficie de 64cm2 provistas con (LEDs) de diferentes longitudes de onda promedio (525 nm verde y 380 nm UV) y sin LED como testigo. Los ensayos mostraron que los adultos de mosca blanca fueron significativamente (p >0,05) más atraídos por las trampas equipadas con LED 525nm verde (134 ± 7,4 adultos/tarjeta) comparadas con trampas equipadas con LED 380 nm UV (105 ± 7,4 adultos/tarjeta) y trampas sin LED (85,17 ± 7,4 adultos/tarjeta). Estos resultados muestran que los adultos de T. vaporariorum son atraídos a trampas dotadas con LED verde, las cuales podrían tener un promisorio uso en invernadero como detección, monitoreo y control de mosca blanca.

Sap-sucking insects (Hemiptera: Sternorrhyncha and Thysanoptera: Thripidae) collected in Java, Sumatra and Sulawesi were identified. From 28 samples collected on 9 crop and ornamental host-plant species, 21 species of sap-sucking insects were identified, 12 (57%) of which were new island distribution records. This suggests that the Indonesian insect fauna has not been documented for a long time. The new distribution records are: from Java, Lepidosaphes gloverii (Packard) (Diaspididae); from Sumatra, Clavaspidiotus apicalis Takagi (Diaspididae); and from Sulawesi, Coccus hesperidum L. (Coccidae), Saissetia coffeae (Walker) (Coccidae), Aulacaspis yasumatsui Takagi (Diaspididae), Hemiberlesia palmae (Cockerell) (Diaspididae), Lepidosaphes tokionis (Kuwana) (Diaspididae), Microparlatoria fici (Takahashi) (Diaspididae), Pseudaulacaspis cockerelli (Cooley) (Diaspididae), Icerya aegyptiaca (Douglas) (Monophlebidae), I. pulchra (Leonardi) (Monophlebidae) and Selenothrips rubrocinctus (Giard) (Thripidae). Clavaspidiotus apicalis could become a potentially invasive pest of citrus.

Sap-sucking insects (Hemiptera: Sternorrhyncha and Thysanoptera: Thripidae) collected in Java, Sumatra and Sulawesi were identified. From 28 samples collected on 9 crop and ornamental host-plant species, 21 species of sap-sucking insects were identified, 12 (57%) of which were new island distribution records. This suggests that the Indonesian insect fauna has not been documented for a long time. The new distribution records are: from Java, Lepidosaphes gloverii (Packard) (Diaspididae); from Sumatra, Clavaspidiotus apicalis Takagi (Diaspididae); and from Sulawesi, Coccus hesperidum L. (Coccidae), Saissetia coffeae (Walker) (Coccidae), Aulacaspis yasumatsui Takagi (Diaspididae), Hemiberlesia palmae (Cockerell) (Diaspididae), Lepidosaphes tokionis (Kuwana) (Diaspididae), Microparlatoria fici (Takahashi) (Diaspididae), Pseudaulacaspis cockerelli (Cooley) (Diaspididae), Icerya aegyptiaca (Douglas) (Monophlebidae), I. pulchra (Leonardi) (Monophlebidae) and Selenothrips rubrocinctus (Giard) (Thripidae). Clavaspidiotus apicalis could become a potentially invasive pest of citrus.

Reported first record of Aleurotrachelus globulariae from the Iberian Peninsula., Se cita por primera vez la especie Aleurotrachelus globulariae para la Península Ibérica.

Reported first record of Aleurotrachelus globulariae from the Iberian Peninsula., Se cita por primera vez la especie Aleurotrachelus globulariae para la Península Ibérica.

Extreme economic effects globally of various populations of the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) led to an in depth study of the morphology of that species as well as that of numerous other species of whiteflies in the genus Bemisia Quaintance and Baker and other similar appearing species. The data collected are presented here as illustrations of the puparia (fourth instar nymphal stages) and discussions of morphology as it relates to species and generic separations within this closely knit group of insects. A brief history of the pest outbreaks of B. tabaci is given and an overview of the important morphological characteristics of aleyrodine whiteflies is provided. Each of the eighty illustrations is accompanied by a discussion of the more important aspects of morphology and how it relates to other populations or species with similar structure and characteristics.

An important part of citrus production at Pará state is planted by Agroforestry System (AFS), that presents, amongst major phytosanitary problems, the citrus blackfly, that by severe attacks cause estimated redution of 80% in its� production. Beside that, it constitutes a quarentenary pest of maximun alert level A2. Given the relevance of this sucking insect and the lack of basic knowledge, as well pest studies associated to agroforestry planting, the objective of this study was to evaluate the abiotic factors influence on blackfly infestation in citrus planting by agroforestry planting at Pará state. This study was carried out at Capitão Poço county, northeast mesoregion of Pará. 12 samplings were made evaluating the presence or abscence of Aleurocanthus woglumi Ashby alive nymphs and/or adults. Correlation analisys was carried out to evaluate abiotic parameters (temperature and precipitation) and kriging maps to evaluate Teca plants shading effects on the pest under study infestation. Amongst the main results obtained, there was pest infestation in every evaluated moth; there was temperature influence onto citrus blackfly population regulation and high precipitations reduced the number of plants with A. woglumi presence. Still, it can be inferred that the citrus blackfly infestations present preference for moderate shading intensity. However, changes occuring by the forestry species introduction onto agricultural cultivations must be better investigated., Importante parcela da produção de citros no estado Pará é plantada em Sistema Agroflorestal (SAF), que apresenta, dentre os principais problemas fitossanitários, a mosca-negra-dos-citros que em ataques severos acarretam redução estimada de 80% na produção. Além de se constitui praga quarentenária presente ou A2 de alerta máximo. Dada a relevância desse inseto sugador e a falta de conhecimentos básicos, bem como estudos da praga associados a plantios agroflorestais, objetivou-se com o presente trabalho avaliar a influência de fatores abióticos na infestação de mosca negra em plantio de citros em sistema agroflorestal no estado do Pará. O presente trabalho foi desenvolvido em área localizada no município de Capitão Poço, mesorregião do Nordeste Paraense. Fez-se 12 amostragens avaliando-se a presença ou ausência de ninfas e/ou adultos vivos de Aleurocanthus woglumi Ashby. Fez-se análise de correlação para avaliar os parâmetros abióticos (temperatura e precipitação) e mapas de Krigagem para avaliar o efeito do sombreamento das plantas de teca na infestação da praga em estudo. Dentre os principais resultados obtidos, verificou-se a infestação da praga em todos os meses avaliados; houve influência da temperatura na regulação da população de mosca-negra-dos-citros e precipitações elevadas reduziram o número de plantas com presença de A. woglumi. Ainda, pode-se inferir que às infestações da mosca-negra-dos-citros apresentam preferência por intensidade moderada de sombreamento, no entanto, as mudanças ocasionadas pela introdução de espécies florestais em cultivos agrícolas, devem ser melhor investigadas.

An annotated list is given of whitefly species of the Netherlands, occurring in the open, indoors in greenhouses and living rooms and those intercepted during import inspections. In this paper over 50 species are mentioned, 14 of which occur in the open, 6 species have been only found in greenhouses and 42 species have been intercepted during quarantine inspections. The majority of the observations stem from the period 1970-2010. Aleurotuba jelinekii and Siphoninus immaculatus are new for the Netherlands, occurring outdoors. Due to regular introductions of species living on traded plants the chance that new species will establish is enhancing.

An annotated list is given of whitefly species of the Netherlands, occurring in the open, indoors in greenhouses and living rooms and those intercepted during import inspections. In this paper over 50 species are mentioned, 14 of which occur in the open, 6 species have been only found in greenhouses and 42 species have been intercepted during quarantine inspections. The majority of the observations stem from the period 1970-2010. Aleurotuba jelinekii and Siphoninus immaculatus are new for the Netherlands, occurring outdoors. Due to regular introductions of species living on traded plants the chance that new species will establish is enhancing.

A mosca-negra-dos-citros, Aleurocanthus woglumi Ashby, é uma séria praga da cultura dos citros e de outras frutíferas de importância econômica. Constitui-se praga quarentenária presente ou A2 de alerta máximo, restringindo o comércio com outras regiões livres de sua presença. A partir de sua primeira ocorrência, no ano de 2001 na cidade de Belém, houve sua rápida disseminação para outros estados e regiões citrícolas do Brasil. Por ser uma praga exótica, conhecimentos básicos são escassos para se implementar o manejo adequado do inseto em território brasileiro. Desse modo, o objetivo do presente estudo é o de disponibilizar informações a respeito de aspectos importantes de A. woglumi, como: histórico e distribuição geográfica, bioecologia, plantas hospedeiras, métodos de controle adotados, dentre outros, a fim de se fornecer subsídios para futuras pesquisas sobre a mosca-negra-dos-citros no Brasil., Citrus blackfly, Aleurocanthus woglumi Ashby, is a serious pest of citrus culture and other economically important fruit crops. It is a present quarantine pest or A2 maximum alert restricting trades with other regions free of its presence. Since the first occurrence of the citrus blackfly in Belém in 2001 its dissemination was quickly to other States and regions of citrus production in Brazil. As an exotic pest, basic knowledge is scarce in order to establish the appropriate management to the insect in Brazil. Thus, the aim of the present study was to provide information about important aspects of A. woglumi, such as: history and geographical distribution, bioecology, host plants, appropriate control methods, among others, in order to provide subsidies for futures researches about the citrus blackfly in Brazil.

An annotated list is given of whitefly species of the Netherlands, occurring in the open, indoors in greenhouses and living rooms and those intercepted during import inspections. In this paper over 50 species are mentioned, 14 of which occur in the open, 6 species have been only found in greenhouses and 42 species have been intercepted during quarantine inspections. The majority of the observations stem from the period 1970-2010. Aleurotuba jelinekii and Siphoninus immaculatus are new for the Netherlands, occurring outdoors. Due to regular introductions of species living on traded plants the chance that new species will establish is enhancing.

Au cours de mon expérience, je me suis intéressé à différents aspects de l'écologie des bioagresseurs allant de l'étude de leurs traits de vie jusqu'à leurs interactions avec l'agroécosystème. Les organismes que j'ai étudiés sont variés : depuis différentes espèces de mouches des fruits, d'aleurodes, de nématodes phytophages jusqu'au charançon du bananier. Deux axes principaux ont structuré mes recherches : un premier concernant la biodémographie et le comportement des bioagresseurs, et un second sur les interactions entre espèces en étudiant en particulier plusieurs espèces envahissantes. Dans le premier axe, j'ai conduit une série de travaux dans lesquels j'ai étudié les traits de vie de différentes espèces au laboratoire et mis en évidence sur le terrain leurs relations avec certains facteurs environnementaux (température, pluviosité, gamme et type de plantes hôtes, type de sol...). Une partie des travaux de ce premier axe a également porté sur la mise au point de systèmes de piégeage contre certains de ces bioagresseurs, et l'étude des biais en termes de structure en âge des populations capturées par ces systèmes. Enfin, des études sur les comportements liés à dispersion du charançon du bananier ont été menées. Dans le second axe, j'ai étudié le lien entre les traits de vie de ravageurs envahissants (mouches des fruits et biotypes d'aleurode) et leur aptitude à l'invasion dans une communauté résidente. Certains traits de vie comme une durée de vie plus longue, une plus grande taille des adultes et des oeufs, permettent une meilleure aptitude à la compétition interspécifique (par exploitation et interférence). L'étude de la distribution géographique de différentes espèces en compétition (mouches des fruits, aleurodes et nématodes phytophages) en fonction des différents facteurs environnementaux a permis de caractériser leurs niches écologiques. Celles-ci conditionnent les possibilités de coexistence des espèces, notamment pour les espèces de bioagresseurs envahis

Eight new state records and the three newly described species are the subject of this publication. Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae: Aleyrodinae) were collected from 2003 through 2009 within the Las Vegas area of Clark County, Nevada to determine the occurrence of newly established species and host range and distribution. Prior to 2003 the following ten whiteflies were known to be established in Nevada: Aleuroglandulus subtilis Bondar, Aleuroplatus berbericolus Quaintance and Baker, Aleyrodes spiraeoides Quaintance, Bemisia tabaci (Gennadius), Dialeurodes citri (Ashmead), Siphoninus phillyreae (Haliday), Tetraleurodes mori (Quaintance), Trialeurodes abutiloneus (Haldeman), Trialeurodes packardi (Morrill), and Trialeurodes vaporariorum (Westwood). Based on collections made after 2003, eleven additional whitefly species were found in Nevada. Of these the following eight were described species from California and other western U.S. states: Aleuroparadoxus arctostaphyli Russell, Aleuroplatus gelatinosus (Cockerell), Aleuropleurocelus ceanothi (Sampson), Aleuropleurocelus nigrans (Bemis), Tetraleurodes quercicola Nakahara, Trialeurodes corollis (Penny), Trialeurodes eriodictyonis Russell, and Trialeurodes glacialis (Bemis). Three new species are described and illustrated: Aleuropleurocelus nevadensis Dooley sp. nov., Tetraleurodes quercophyllae Dooley sp. nov., and Trialeurodes pseudoblongifoliae Dooley sp. nov.

Au cours de mon expérience, je me suis intéressé à différents aspects de l'écologie des bioagresseurs allant de l'étude de leurs traits de vie jusqu'à leurs interactions avec l'agroécosystème. Les organismes que j'ai étudiés sont variés : depuis différentes espèces de mouches des fruits, d'aleurodes, de nématodes phytophages jusqu'au charançon du bananier. Deux axes principaux ont structuré mes recherches : un premier concernant la biodémographie et le comportement des bioagresseurs, et un second sur les interactions entre espèces en étudiant en particulier plusieurs espèces envahissantes. Dans le premier axe, j'ai conduit une série de travaux dans lesquels j'ai étudié les traits de vie de différentes espèces au laboratoire et mis en évidence sur le terrain leurs relations avec certains facteurs environnementaux (température, pluviosité, gamme et type de plantes hôtes, type de sol...). Une partie des travaux de ce premier axe a également porté sur la mise au point de systèmes de piégeage contre certains de ces bioagresseurs, et l'étude des biais en termes de structure en âge des populations capturées par ces systèmes. Enfin, des études sur les comportements liés à dispersion du charançon du bananier ont été menées. Dans le second axe, j'ai étudié le lien entre les traits de vie de ravageurs envahissants (mouches des fruits et biotypes d'aleurode) et leur aptitude à l'invasion dans une communauté résidente. Certains traits de vie comme une durée de vie plus longue, une plus grande taille des adultes et des oeufs, permettent une meilleure aptitude à la compétition interspécifique (par exploitation et interférence). L'étude de la distribution géographique de différentes espèces en compétition (mouches des fruits, aleurodes et nématodes phytophages) en fonction des différents facteurs environnementaux a permis de caractériser leurs niches écologiques. Celles-ci conditionnent les possibilités de coexistence des espèces, notamment pour les espèces de bioagresseurs envahis

Integrated Pest Management reduces the use of chemicals and therewith the impact of greenhouse horticulture on the environment. It improves working conditions and enables access of Ethiopian products on the world market. In response to such concerns the Ethiopian Horticulture Producers and Exporters Organization (EPHEA) has taken the initiative to develop a Code of Practice, of which Integrated Pest Management forms an integral part. The development of this Integrated Pest Management approach is supported through the Ethiopia-Netherlands Horticulture Partnership Programme.

In komkommer, aubergine en paprika is de wittevliegbestrijding aanzienlijk verbeterd sinds de introductie van de generalistische roofmijt Amblyseius swirskii. Op veel tomatenbedrijven gaat de biologische bestrijding van wittevlieg met roofwantsen en sluipwespen echter nog moeizaam in de winter-voorjaar-periode. In dit onderzoek hebben we vijf soorten roofmijten (Amblyseius swirskii, Euseius ovalis, Typhodromalus limonicus, Amslyseius montdorensis, Amslyseius alpinus) en voor soorten rooftripsen (Scolothrips sexmaculatus, Scolothrips longicornis, Scolothrips takahashii, Franklinothrips vespiformis) getest tegen kaswittevlieg in tomaat. In twee kasproeven met roofmijten konden alleen A. mondorensis en T. limonicus zich enige tijd op het gewas handhaven. Na 6 weken waren ook deze soorten verdwenen, ook al was er voldoende prooi beschikbaar. Bij geen enkele soort was er een effect op kaswittevlieg te zien. In het laboratorium bleken alle rooftripsen zich te voeden met eieren en larven van kaswittevlieg op tomatenblad. Géén van deze rooftripsen was echter in staat zich te vestigen op een tomatenplant met witte vlieg en er werd dan ook géén onderdrukkend effect op witte vlieg waargenomen. De slechte vestiging van de rovers is waarschijnlijk toe te schrijven aan de klierharen van tomaat, die bij contact kleverige en toxische stoffen afscheiden, waar kleine predatoren last van hebben.

Unisexual Trichogramma forms have attracted much attention due to their potential advantages as biocontrol agents. Fitness studies have been performed and understanding the cost that Wolbachia may inflict on their hosts will help in deciding if Wolbachia infected (unisexual) forms are indeed better than sexual forms when used in biological control programmes. The influence of Wolbachia on the foraging behaviour (including walking activity and speed) of T. atopovirilia is reported in this paper. Temperature strongly affected T. atopovirilia female walking activity, but Wolbachia infected and uninfected females differed in none of the behavioural components that were measured such as walking activity and walking speed. Walking activity was highest at 25 ºC and differed significantly from that at 20 and 15 ºC. Trichogramma wasps were highly affected at 15 ºC. Behaviour analysis with females showed that female wasps spend most of the time on drilling + ovipositing on host eggs followed by host drumming and walking while drumming. The parasitism rate and number of offspring did not differ significantly between infected and cured Trichogramma females. Biological control implications of these findings are discussed.

PreFeRal is een biologisch middel dat goed werkt tegen wittevlieg in de teelten onder glas. Het middel is goed te gebruiken in de geïntegreerde gewasbescherming, geeft geen residu en heeft geen wachtdagen. Het is te mengen met andere middelen, behalve met fungiciden. Het klaarmaken van de spuitvloeistof kost tijd en na toepassing moet het gewas zo lang mogelijk vochtig blijven

Bladmonsters werden verzameld op rozenbedrijven om vast te stellen welke natuurlijke vijanden op deze waardplant voorkomen. Deze inventarisatie werd uitgevoerd op veertig bedrijven, die al dan niet roofmijten hadden geïntroduceerd. In spinthaarden werden Phytoseiulus persimilis, Amblyseius cucumeris, Amblyseiuscalifornicus, Amblyseius barkeri en Amblyseius andesoni gevonden. In wittevlieghaarden troffen we Encarsia formosa en Eretmocerus eremicus aan. Alleen de kaswittevlieg werd waargenomen, geen tabakswittevlieg. Tijdens latere bedrijfsbezoeken werden nog twee andere soorten roofmijten gevonden: Iphiseius degenerans en Amblyseius aurescens. Soortgelijke bemonsteringen werden ook gedaan op buitenrozen door PPO Bomen. Daarbij werden de volgende soorten roofmijten gevonden: Amblyseiuscalifornicus, Amblyseius rademacheri, Kampimodromus aberrans, Amblyseius andersoni en Euseiusfinlandicus. Vooral de twee laatste bieden perspectief voor de bestrijding van spintmijten in roos en werden gekweekt bij PPO Bomen en later ook bij PPO Glas.

Biological control of Trialeurodes vaporariorum (Westwood) by Encarsia formosa Gahan was tested during three consecutive production cycles (16-28 weeks) on a beef tomato (Solanum lycopersicum L.) crop in a glasshouse and a plastic greenhouse on the Bogota Plateau in Colombia. During the course of this study over the period 1997-1999, the mean temperature was around 16 °C in the plastic greenhouse and around 17 °C in the glasshouse. E. formosa was introduced at a rate of 3 adults per m2 per week in the 1997 production cycle, and at a rate of 3 and 5 pupae per m2 per week in 1998 and 1999, respectively. In 1997, the adult whitefly population increased exponentially to a peak of 76 adults per plant in the plastic greenhouse, while the whitefly population in the glasshouse reached a peak of only 12 adults per plant. The percentage parasitism fluctuated between 42 and 82% in the glasshouse and between 28 and 47% in the plastic greenhouse. In 1998, the T. vaporariorum population could not be brought under control in both greenhouses and reached a peak of 80 and 53 T. vaporariorum adults per plant in the plastic greenhouse and the glasshouse, respectively. Parasitism fluctuated between 55 and 97% in the glasshouse and between 32 and 84% in the plastic greenhouse. In 1999, biological control was successful in both greenhouses. Most of the time, populations of T. vaporariorum were lower than 1.2 adults per plant and parasitism by E. formosa was 80% or higher. We suggest that the higher temperature is the main reason for better parasitism in the glasshouse when compared to the plastic greenhouse. The successful results of 1999 show that biological control is possible under the short day and low temperature conditions of greenhouses situated in the high altitude tropics such as the Bogota Plateau. Recommendations are given for the application of E. formosa based on the results of these experiments.

Biological control of Trialeurodes vaporariorum (Homoptera Aleyrodidae) by Amitus fuscipennis (Hymenoptera Platygastridae) with or without Encarsia formosa (Hymenoptera Aphelinidae) was tested in both a glasshouse and a plastic greenhouse during two consecutive production cycles of a beef tomato crop on the Bogotá Plateau in Colombia. The mean temperature was around 16 °C in the plastic greenhouse and around 17 °C in the glasshouse. A. fuscipennis was introduced at a rate of 5 pupae per m2 per week during the first 13 weeks of the first cycle. During the second cycle, 2.5 pupae of both E. formosa and A. fuscipennis per m2 per week were introduced during the first 13 weeks. During the first cycle, control was obtained for 5 months in the plastic greenhouse and 3 months in the glasshouse, after which the population of T. vaporariorum adults increased to a maximum of 50 adults per plant. Parasitism was initially higher than 80% but then decreased to 56% in the plastic greenhouse and to 20% in the glasshouse. During the second cycle, biological control was successful in both greenhouses. Populations of T. vaporariorum were lower than 1.2 adults per plant and parasitism, caused mainly by E. formosa, was near 90% most of the time. Therefore, E. formosa is recommended to keep populations of T. vaporariorum at low levels in unheated greenhouses on the Bogotá Plateau. When high populations of T. vaporariorum are to be expected or control of high-density spots is required, A. fuscipennis could be a beneficial addition to E. formosa.

Op 25 januari 2007 werd door de LTO een bijeenkomst georganiseerd met als thema 'Gerbera'. Juliette Pijnakker van Wageningen Universiteit hield een voordracht over de 'Bestrijding van kaswittevlieg in gerbera'. Middels een PowerPoint presentatie werden de resultaten van gehouden kooiproeven in 2005 met roofmijten en de vervolgproeven, door haar uiteengezet

We studied the effect of UV-blocked greenhouses made from netting and plastics on the movement and pest status of three important pest of tomatoes: whitefly (Bemisia tabaci), thrips (Ceratothripoides claratris), and aphid (Aphis gossypii). Under UV-blocked greenhouses, fewer whiteflies, aphids, and thrips entered the greenhouse compared with the ones having more UV intensity. Similarly, significantly fewer alate aphids and adult B. tabaci/leaf were counted in greenhouses with low UV intensity. Although thrips were the most abundant pest, they also were significantly less abundant in greenhouses with lower UV intensity. Consequently, significantly lower levels of leaf infestation were recorded under these greenhouse conditions. During open gates experiments, virus infection levels reached 96-100% under UV nonblocking greenhouses compared with 6-10% infection levels in greenhouses where UV irradiation was blocked. In addition, the appearance of virus symptoms was considerably delayed under greenhouses made from the UV-blocking roof material, although the majority of the plants tested positive for the tospovirus, capsicum chlorosis virus (CaCV; AIT isolate). The results are discussed in context of improved management of sucking insect pests of tomatoes in the humid tropics.

Human-mediated bioinvasions provide the opportunity to study the early stages of contact between formerly allopatric, divergent populations of a species. However, when invasive and resident populations are morphologically similar, it may be very difficult to assess their distribution in the field, as well as the extent of ecological overlap and genetic exchanges between invasive and resident populations. We here illustrate the use of data obtained from a set of eight microsatellite markers together with Bayesian clustering methods to document invasions in a group of major tropical pests, Bemisia tabaci, which comprises several morphologically indistinguishable biotypes with different agronomic impacts. We focus on the island of La Réunion, where an invasive biotype (B) has recently been introduced and now interacts with the resident biotype (Ms). The temporal and spatial distribution, host-plant range and genetic structure of both biotypes are investigated. We showed (i) that, without prior information, clustering methods separate two groups of individuals that can safely be identified as the B and Ms biotypes; (ii) that the B biotype has invaded all regions of the island, and showed no signs of genetic founder effect relative to the Ms biotype; (iii) that the B and Ms biotypes coexist in sympatry throughout most of their geographical ranges, although they tend to segregate into different host plants; and finally (iv) that asymmetrical and locus-specific introgression occurs between the two biotypes when they are in syntopy.

Erk Zwinkels heeft na een jaar ervaring met belichte tomatenteelt geconstateerd dat het in het begin van de teelt moeilijk is om biologisch evenwicht op te bouwen. Hij zorgt er nu in de eerste plaats voor om schoon de eerste twee maanden door te komen en dan pas de biologische gewasbescherming rustig op te bouwen. Liever eerst even de tijd nemen om alles schoon te hebben, om later in de teelt vrijwel niet meer te hoeven bijsturen

Five species of whiteflies, Aleurolobus iteae Takahashi, Aleurolobus vitis Danzig, Asterobemisia takahashii Danzig, Bemisiella artemisiae Danzig, and Massilieurodes euryae (Takahashi), are newly recorded from Korea.

Aleuroclava magnoliae (Takahashi), Aleurotrachelus ishigakiensis (Takahashi), Aleyrodes lonicerae Walker, Asterobemisia carpini (Koch), Bemisia afer (Priesner and Hosny), Dialeurolobus pulcher Danzig, Pealius polygoni Takahashi, and Pealius rubi Takahashi are newly recorded from Korea.

In komkommer was de soms matige tripsbestrijding met de standaard roofmijt Neoseiulus (Amblyseius) cucumeris aanleiding om nog eens goed te kijken naar de mogelijkheden voor nieuwe roofmijtsoorten. In 2003 werden negen soorten uit de familie Phytoseiidae (bladbewonende roofmijtsoorten) geselecteerd. Drie soorten scoorden significant beter als bestrijder van trips en bereikten significant hogere roofmijtdichtheden dan de standaard roofmijt N. cucumeris. Dit waren de subtropische soorten Typhlodromalus limonicus, Typhlodromips swirskii en Euseius ovalis. Vooral T. limonicus en T. swirskii bereikten opvallend hoge dichtheden wat resulteerde in een respectievelijk 12 en 9 keer zo grote populatie als bij als N. cucumeris. “Nieuwe” inheemse roofmijtsoorten, afkomstig van Cucurbitaceae, scoorden niet beter dan N. cucumeris. De nieuwe roofmijt T. swirskii was ook op gewasniveau een significant betere bestrijder van trips dan N. cucumeris. Een vergelijkingsproef liet bovendien zien dat T. swirskii in staat is om een populatie N. cucumeris volledig te verdringen.

#Aleurotrachelus atratus# Hempel, 1922, et #Paraleyrodes bondari# Peracchi, 1971, sont signalés pour la première fois des Comores. Les dégâts occasionnés sont très importants sur Cocotier (#Cocos nucifera#). #A. atratus# est de loin l'espèce la plus abondante. Les dégâts sont décrits, leur importance et leur répartition dans l'archipel sont données. L'introduction remonte probablement à quelques années. Quelques auxiliaires ont été observés.

Het PPO onderzocht drie soorten roofmijt op hun effect op kaswittevlieg in komkommer. Typhlodromalus limonicus kwam als beste uit de bus, maar is helaas niet massaal te kweken

The main aim of evolutionary ecology is to explain the adaptation of form, function and behaviour of organisms to their environment. In this thesis, I studied host-handling behaviour of the whitefly parasitoid Encarsia formosa form such an evolutionary point of view. This parasitoid is applied as biological control agent against whitefly pests in greenhouses. Previous studies revealed mechanistic explanations for the parasitoid's behaviour. Here I focussed on functional explanations for the parasitoid's decision to reject, feed upon or parasitise a host. Since host feeding yields nutrients for egg maturation but destroys an opportunity to oviposit, the decision between host feeding and oviposition reflects a life-history trade-off between current and future reproduction.First, manipulation experiments were conducted to seek for evolutionary benefits of destructive host feeding over non-destructive feeding on host-derived honeydew. The first experiments suggested that honeydew could be an advantageous alternative to host feeding. Honeydew did have a positive effect on egg load and estimated number of eggs matured within 20 and 48 hours, whereas a host feeding did not. Host feeding did not positively affect survival when honeydew was supplied. In the second experiments the observation period was extended. Even in the presence of honeydew, host feeding did have a positive effect on the number of ovipositions per hour of foraging per host-feeding attempt, without affecting parasitoid survival or egg volume.To understand the conditions under which E. formosa has evolved, fieldwork was carried out in Costa Rica to quantify natural whitefly densities and distributions. The number of hosts on the lower side of a leaflet of an average plant within an average spot along an average transect could be described by a Poisson distribution with mean and variance equal to 0.241. This mean was most variable at plant level. Spatial dependence between numbers of whiteflies on leaves wa