• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • Tagged with
  • 6
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efecto de Imidacloprid aplicado al follaje y al tronco para el control de Pseudococcidae en naranjos.

Cataldo Adasme, Leandro January 2004 (has links)
Memoria para optar al Título Profesión de Ingeniero Agrónomo Mención: Fruticultura / Pseudococcidae (chanchitos blancos) en naranjos, aplicándolo en enero del 2003 con dos sistemas de aplicación; al follaje (80, 100, 120 cc p.c./Hl) con una motopulverizadora y al tronco con una pistola asperjadora (9 y 12 cc p.c./árbol). Estos tratamientos se contrastaron con Clorpirifos aplicado sólo y vs. un programa de control con Clorpirifos aplicado en enero e Imidacloprid 60 días antes de la cosecha (junio/2003). / A new Imidacloprid formulation (Confidor Forte 200 SL) was evaluated against Pseudococcidae (mealybugs) on orange trees; the application was made in January 2003 utilizing two different spray systems: hand spray gun on the foliage using rates of 80, 100, 120 cc c.p/Hl, and a “pistol” (trigger pump-like) sprayer to apply localized on the bark using 9 and 12 cc c.p./tree. These treatments were compared to Chlorpyriphos applied alone and vs. a program including Chlorpyriphos applied in January and Imidacloprid applied 60 days before harvest (June/2003).
2

Inimigos naturais de cochonilhas (Hemiptera: Sternorrhyncha: Coccoidea) associadas a plantas de importância econômica no estado de São Paulo / Natural enemies of scale insects (Hemiptera: Sternorrhyncha: Coccoidea) associated with economic important plants in the state of São Paulo

Cruz, Maiara Alexandre 28 February 2018 (has links)
Submitted by MAIARA ALEXANDRE CRUZ (maiara_agronomia@hotmail.com) on 2018-04-16T14:10:46Z No. of bitstreams: 2 Dissertaçao_Maiara_Alexandre_Cruz.pdf: 2216345 bytes, checksum: c797b70103395ccc0e6fb5cc74a155ef (MD5) DISSERTAÇÃO COMPLETA repositorio.docx: 2205488 bytes, checksum: 87334bbb24da1f49c2f7403a20b4b5ea (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-16T18:24:58Z (GMT) No. of bitstreams: 1 cruz_ma_me_jabo.pdf: 2216345 bytes, checksum: c797b70103395ccc0e6fb5cc74a155ef (MD5) / Made available in DSpace on 2018-04-16T18:24:58Z (GMT). No. of bitstreams: 1 cruz_ma_me_jabo.pdf: 2216345 bytes, checksum: c797b70103395ccc0e6fb5cc74a155ef (MD5) Previous issue date: 2018-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / RESUMO – A agricultura é de suma importância para o desenvolvimento do Brasil. O estado de São Paulo, com significativa produção e produtividade de diversas culturas, é o maior produtor de cana-de-açúcar e citros, e o terceiro em café. No entanto, grandes perdas econômicas e ambientais ocorrem pelo uso indiscriminado de agrotóxicos para controlar insetos-praga, incluindo cochonilhas. Informações sobre insetos benéficos atualmente presentes nas regiões produtoras são fundamentais para o manejo integrado de pragas. Este estudo teve como objetivo fazer um levantamento de inimigos naturais associados a espécies de cochonilhas consideradas pragas, primárias ou secundárias, para as culturas de cana-de-açúcar, citros e café no estado de São Paulo, relacionando à origem de cada espécie; especificidade a presa; e as possíveis adaptações a predação ou parasitismo em relação às características morfológicas macroscópicas das cochonilhas. O levantamento de inimigos naturais associados com dez espécies de cocóideos frequentemente associados a estas plantas foi realizado em 15 municípios, situados nas mesorregiões de São José do Rio Preto, Ribeirão Preto, Araraquara e Campinas. As coletas foram realizadas entre agosto de 2016 e agosto de 2017, de maneira aleatória, em áreas urbana e rural. Nesse período, foram coletadas 52 espécies de inimigos naturais. Para cochonilhas da cana-de-açúcar, todas as associações são novos relatos para o estado de São Paulo; e, Anagyrus saccharicola Timberlake, 1932 e Mariola flava Noyes, 1980 (Hymenoptera: Encyrtidae) sâo registrados pela primeira vez para o para o país. Entre as cochonilhas que frequentemente infestam citros e café, e seus respectivos inimigos nturais. 21 novas associações foram registradas. Dentre os predadores obtidos, Pseudoazya nana (Marshall, 1912) (Coleoptera: Coccinelidae), e, os parasitoides Arrhenophagus chionaspidis Aurivillius, 1888, Coccidoxenoides perminutus Girault, 1915 (Hymenoptera: Encyrtidae), Coccophagus basalis Compere, 1939 (Hymenoptera: Aphelinidae), são registrados pela primeira vez para o estado de São Paulo. Para o Brasil são registrados: Coccophagus flavifrons Howard, 1885 e Coccophagus rusti Compere, 1928 ((Hymenoptera: Aphelinidae). / ABSTRAT– Agriculture is of great importance for the development of Brazil. The state of São Paulo, with significant production and productivity of several crops, is the largest producer of sugarcane and citrus, and the third in coffee. However, major economic and environmental losses occur through the indiscriminate use of pesticides to control pest insects, including scale insects. Information on beneficial insects currently present in producing regions is essential for integrated pest management. The objective of this study was to survey natural enemies associated with scale insects species considered as primary or secondary pests for sugarcane, citrus and coffee crops in the state of São Paulo, relating to the origin of each species; specificity prey; and the possible adaptations to predation or parasitism in relation to the macroscopic morphological characteristics of scale insects. The survey of natural enemies associated with ten coccoid species frequently associated with these plantations was carried out in 15 municipalities located in the mesoregions of São José do Rio Preto, Ribeirão Preto, Araraquara and Campinas, in the main sugarcane producing regions, citrus and state coffee. The collections were carried out between August 2016 and August 2017, in a random manner, in urban and rural areas. During this period, 52 species of natural enemies were collected. For sugarcane scale insects, all associations are new reports for the state of São Paulo; and, Anagyrus saccharicola Timberlake, 1932 and Mariola flava Noyes, 1980 (Hymenoptera: Encyrtidae) are recorded for the first time to the country. Among the scale insects that frequently infest citrus and coffee, and their respective nemes. 21 new associations were registered. Among the predators obtained, Pseudoazya nana (Marshall, 1912) (Coleoptera: Coccinelidae), and the parasitoids Arrhenophagus chionaspidis Aurivillius, 1888, Coccidoxenoides perminutus Girault, 1915 (Hymenoptera: Encyrtidae), Coccophagus basalis Compere, 1939 (Hymenoptera: Aphelinidae), are registered for the first time to the state of São Paulo. For Brazil are recorded: Coccophagus flavifrons Howard, 1885 and Coccophagus rusti Compere, 1928 ((Hymenoptera: Aphelinidae).
3

Survey of different mealybug species and attending ants and their management in Virginia vineyards

Chalise, Pragya 01 November 2023 (has links)
Mealybugs (Order Hemiptera: Superfamily Coccoidea) represent a persistent problem in grape-growing regions globally, with a notable increase in infestations in recent times. The current study investigates the species composition and seasonal dynamics of mealybugs in vineyards. Pseudococcus maritimus and Ferissia gilli remain the dominant species, while Pseudococcus viburni was also spotted during two separate instances and Planococcus ficus remained absent. Commercially available pheromone delta traps and adhesive bands were deployed to capture the male mealybugs, while numerically higher efficacy was observed in the adhesive band trap. Notably, the placement of adhesive band traps on the cordon and trunk revealed differential male mealybug captures, probably indicating their movement within the vines. The research also divulges into the life cycle of mealybugs and their population densities during the sampling season. The main highlight has been the lower population density of earlier nymphal stages of the first generation of mealybugs followed by the colonization of grapevines by the second-generation crawlers. Adults of second generations give rise to the overwintering stages of mealybugs. Traditionally the research also explores the species and seasonal population dynamics of ants along with mealybugs and their management in Virginia vineyards. The activity of fifteen genera of ants in the vineyard was recorded, with some of the dominant ant genera like Tetramorium, Crematogaster, and Lasius were recorded in the vineyard actively tending and defending the mealybugs and moving them around. Fruit cluster infestation was also higher in the control treatment in comparison to sugar dispenser and ant bait dispenser treatments. This comprehensive assessment of ant diversity further deepens our understanding of the intricate ecosystem within vineyards. A spray trial using three different insecticides with distinct modes of action (Buprofezin, Bifenthrin, and Spirotetramat) in two of the commercial vineyards. Preliminary results indicate that on some days after treatment, insecticides effectively controlled mealybug populations, offering a glimmer of hope to vineyard owners grappling with infestations. Mealybugs pose a significant threat to grape cultivation, and this research provides valuable insights that can help vineyard owners and grape growers develop more targeted and effective control strategies. Species identification, understanding their behavior, and exploring potential allies in the fight against mealybugs are all crucial steps toward maintaining the health and productivity of vineyards in Virginia. While challenges remain in the battle against mealybugs, this research marks a significant step forward in safeguarding grape cultivation in Virginia and potentially reshaping strategies for controlling these persistent pests in vineyards. Growers and researchers alike eagerly await further developments and the practical application of these findings to protect the flourishing vineyards of the region. / Doctor of Philosophy / Mealybugs are common grapevine pests, recently causing a nuisance in vineyards across the United States and Canada. Some of the previously documented species of mealybugs common in the eastern part of the States include grape mealybug, obscure mealybug, Gill's mealybug, and long-tailed mealybugs. The research has mainly addressed the mealybugs and their tending ant species and their management in vineyards in Virginia. The study identifies grape mealybug and Gill's mealybug as the dominant species with occasional sightings of obscure mealybug and a lack of vine mealybug throughout the sampled vineyard sites. The male mealybugs were monitored using commercially available pheromone delta traps and adhesive band traps. Placement of adhesive band traps in the cordon and trunk of grapevines revealed different male mealybug capture data suggesting their movement within the grapevines. Two generations of mealybugs including the first generation with lower population density emerging out from the overwintering life-stage and the subsequent second generation responsible for colonizing different parts of the grapevines and producing overwintering life-stages were observed. Fifteen genera of ants were sampled from the vineyard via pitfall trap with some ants like pavement ants, acrobat ants, and medium garden ants actively tending and protecting the mealybugs. The use of sugar dispensers in the vineyards also led to lower fruit cluster infestations with mealybugs in comparison to the area without dispensers. The insecticidal spray trial using three different insecticides was also effective in controlling populations of mealybugs on some of the dates after treatment. The research offers valuable insights for grape growers, aiding in the development of effective control strategies for mealybug control. It emphasizes the importance of identifying the species present, understanding their behavior, and exploring potential allies and insecticide options in pest management.
4

A molecular phylogenetic study and the use of DNA barcoding to determine its efficacy for identification of economically important scale insects (Hemiptera: Coccoidea) of South Africa

Sethusa, Mamadi Theresa 15 July 2014 (has links)
Ph.D. (Zoology) / Scale insects, plant pests of quarantine importance, with specialised anatomy and unresolved phylogenetic relationships, are responsible for major economic losses to South Africa and its trading partners. These losses may reach critical levels if the pests are not timely identified and controlled. They are currently identified based on published keys of adult females, a process that takes three days to two weeks depending on the family and the life stage of interception. In addition, agricultural commodities are often contaminated with different life stages, males or damaged specimen of these pests, making identification difficult or impossible. As a result, shipments of agricultural produce are often rejected and trade disrupted. Furthermore, pest invasions do not only occur by importation via formal channels. At times pests cross boarders as contaminants of undeclared material and may again spread on their own as they naturally expand their range. This expansion may be negatively or positively influenced by other factors such as climate change. Resolving the challenges associated with identification, phylogenetic relationships and the limited knowledge of the effects of climate change on distribution range of scale insects are the main goals of this study. Specifically (i) the development of a rapid method of species identification, (ii) the relationship between and within three major scale insect families the Coccoidea, Diaspididae and Pseudococcidae and (iii) the effect of climate change on the future distribution range of scale insects in South Africa were explored...
5

Biología y control del cotonet Planococcus citri (Homoptera: Pseudococcidae) en huertos de cítricos

Martínez Ferrer, María Teresa 11 April 2013 (has links)
Planococcus citri se considera una plaga importante de los cítricos en todo el mundo. El manejo de este fitófago se basa en los principios de la Producción Integrada, que requiere conocimientos precisos sobre la biología, ciclo estacional y comportamiento de las poblaciones de P. citri. Entre los años 1992 a 1998 se ha realizado un seguimiento de las poblaciones de P. citri y de sus enemigos naturales en diversas parcelas de cítricos tratadas y no tratadas con productos fitosanitarios. Estos seguimientos se han realizado tanto en diferentes partes del árbol como con trampas pegajosas con feromona sexual. En la zona de estudio, P. citri desarrolló cinco generaciones al año. La temperatura crítica de desarrollo y la integral térmica de P. citri fueron 8,3°C y 562,4°C-día, respectivamente. Las larvas de primera edad invadieron el cáliz de los frutos en los meses de mayo a julio, alcanzando en julio valores elevados en porcentaje de cálices invadidos, con una media del 72. P. citri invadió el fruto desde el cáliz a partir del mes de agosto, con una media de parcelas y años de un 22 de frutos atacados exteriormente. La población de P. citri fluctuó durante los años sucesivos, en parcelas no tratadas, manteniéndose entre un 10 y un 30 de frutos atacados. Los pesticidas organofosforados aplicados en primavera controlaron satisfactoriamente la población de P. citri. Hemos determinado que los umbrales de tratamiento son, en primavera, un 70 de cálices de los frutos ocupados y en agosto y septiembre, un 20 de frutos ocupados. La población de P. citri mostró una pauta de distribución agregativa bajo el cáliz de los frutos, sobre los frutos y en el tronco, con el índice de Taylor b de 1,45, 1,41 y 1,42 respectivamente. Se aconseja muestrear unos 130 frutos mediante un muestreo enumerativo en el caso de poblaciones bajas y medias, y 200 frutos mediante un muestreo binomial para poblaciones elevadas. El control biológico ejerció una función muy importante en la regulación de .... / Martínez Ferrer, MT. (2003). Biología y control del cotonet Planococcus citri (Homoptera: Pseudococcidae) en huertos de cítricos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/27775
6

Biology and management of the invasive mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae) in urban landscapes

Beltrà Ivars, Aleixandre 06 May 2014 (has links)
Phenacoccus peruvianus (Hemiptera: Pseudococcidae) is an invasive mealybug of Neotropical origin, first reported in the Mediterranean Basin in Almeria (Spain) in 1999. In the following years the mealybug spread into other Mediterranean regions and has also been recorded in Portugal and France, as well as in Sicily, Corsica and the Balearic Islands. Phenacoccus peruvianus is a polyphagous species and damages economically important ornamental plants. Since this was a relatively unknown species, during the first years of invasion, the mealybug was managed by the application of chemical treatments with wide-spectrum pesticides. However, the latest European directive on pesticide use reduces or even forbids pesticide applications in a wide range of urban green areas, giving significant priority to biological control (European Parliament and Council 2009). This thesis sets the basis for introducing biological control into a P. peruvianus management program in urban landscapes, focusing on its characterization, sampling, biology and control. In order to facilitate the identification of this and other mealybug species, we characterised 33 mealybug populations infesting crops and ornamental plants in Eastern Spain, using a combination of molecular and morphological techniques. This characterisation led to the identification of ten mealybug species and made routine identification possible through DNA sequencing or the use of derived species-specific molecular tools. The sequences obtained also add to the phylogenetic knowledge of the Pseudococcidae family and provide insight into the invasion history of some species. Phenacoccus peruvianus populations were high in bougainvillea plants during spring and summer, declining to almost undetectable levels in autumn and winter. The mealybug was mainly found in bracts and there were no significant migrations between plant strata. Phenacoccus peruvianus showed a high aggregated distribution on bracts, leaves and twigs. We recommend a binomial sampling of 200 leaves and an action threshold of 55% infested leaves for IPM purposes in urban landscapes. Its most abundant natural enemies were found to be the primary parasitoids Acerophagus n. sp. near coccois and Leptomastix epona Walker (Hymenoptera: Encyrtidae). We also identified several predator species from the Anthocoridae, Coccinellidae, Chamaemyiidae, and Chrysopidae families. Phenacoccus peruvianus populations were lower during the second and third year of the survey, coinciding with an increase in the parasitoid Acerophagus sp. populations, which displaced the native L. epona. Differential female offspring and resource preemption are discussed as the main reasons for this displacement. To obtain further information on the biology of the new parasitoid Acerophagus sp. we determined some traits of its reproductive and feeding strategies. Acerophagus sp. egg load reached its maximum when it was 5 days old with almost 30 mature eggs. Phenacoccus peruvianus second and third nymphal instars and adults were suitable for parasitism and efficient encapsulation was low (10.76 ± 0.31 %). The parasitoid always preferred older instars when different host instars were available. Acerophagus sp. developed as a solitary parasitoid in the second instar and as a gregarious parasitoid in older instars (2¿4 parasitoids per host). Moreover, it reproduced parthenogenetically and all the emerged offspring were females. Immature development lasted between 20 and 22 days at 25°C and 65% HR. Under these conditions, adults lived for longer than 20 days when fed on honey, but fewer than 3 days when fed on naturally occurring sugar sources (host honeydew and Bougainvillea glabra flowers). / Beltrà Ivars, A. (2014). Biology and management of the invasive mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae) in urban landscapes [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37233

Page generated in 0.0272 seconds