Thesis (M.Ag.Sci.) -- Department of Entomology,Waite Agricultural Research Institute, University of Adelaide, 1979.

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Mem oria par a optar al Título Profes ional de Ingen iero Agró nomo. Mención: San idad Ve getal / Se evaluó el efecto insecticida de los detergentes de uso agrícola SU 120 y Tecsa Fruta, sobre hembras adultas y ninfas de segundo estado de Pseudococcus longispinus (Targioni y Tozzetti) en laboratorio. La mortalidad (%) a las 24 h se sometió a análisis Probit, para obtener las dosis letales 50 (DL50). Para Tecsa Fruta se utilizó un volumen de aspersión de 9,5 mL de solución, mientras que para SU 120 se evaluaron tres volúmenes (2, 4 y 8 mL de solución), usando Torre de Poter. La mortalidad fue directamente proporcional a la dosis usada en ambos detergentes en todos los volúmenes evaluados. Las DL50 para Tecsa Fruta fueron 17,9 mL p.c/100 mL de solución para hembras y 5,4 para ninfas de segundo estado, mientras que para SU 120 fueron 3,1; 1,6; 1,9 mL p.c/100 mL de solución en hembras adultas y 0,8; 0,5; 0,5 mL p.c./100 mL de solución en ninfas de segundo estado, para los volúmenes de 2, 4 y 8 mL de solución, respectivamente. En ninfas no hubo diferencias significativas entre los volúmenes aplicados, y en hembras adultas los tratamientos con 4 y 8 mL de solución no presentaron diferencias estadísticas, aunque con ambos volúmenes se obtuvieron DL50 inferiores estadísticamente respecto al tratamiento con 2 mL de solución. SU 120 presentó efecto insecticida significativamente mayor que Tecsa Fruta en ninfas de segundo estado y hembras adultas de P. longispinus. Las ninfas de segundo estado fueron más susceptibles que las hembras adultas.

No disponible a texto completo / Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Sanidad Vegetal / En este trabajo se evaluó el efecto de azufre (Azufre floable AN 600, 600 g/ hL), aceite mineral (Purespray 22E, 1,5%) y spinosad (Entrust*, 20 g/ hL) sobre Pseudaphycus flavidulus y Cryptolaemus montrouzieri bajo condiciones de laboratorio. Los productos fueron aplicados usando dos modalidades: aspersión con Torre de Potter a 15 lb/in2 durante 25 segundos e inmersión por 5 segundos en la solución insecticida. Se empleó un diseño de aleatorización completa con 4 tratamientos, 4 repeticiones por tratamiento y 25 individuos por unidad experimental. Se evaluó la mortalidad al día 1, 3 y 7 post aplicación. Los valores expresados en porcentaje se normalizaron mediante la transformación angular de Bliss y luego se sometieron a Andeva y prueba de Snk para separación de medias. El estudio determinó que azufre, aceite y spinosad asperjados sobre P. flavidulus, tienen un efecto significativo en la mortalidad de la microavispa, mientras que en la modalidad de inmersión los insecticidas produjeron la mortalidad de la totalidad de los individuos al no tener el intercambio gaseoso necesario para su sobrevivencia. En el caso de C. montrouzieri el producto asperjado que más afecta la mortalidad de este depredador es el azufre, seguido por spinosad. En cambio, en la modalidad de inmersión es el aceite el tratamiento que produce el efecto más negativo seguido por el azufre. / This work evaluated the effect of sulphur (Flowable Sulphur AN 600, 600 g/hL), mineral oil (Purespray 22E, 1,5%) and spinosad (Entrust*, 20 g/hL) on Pseudaphycus flavidulus and Cryptolaemus montrouzieri under laboratory conditions. Products were applied using two methods: spraying with potter tower at 15 lb/in2 for 25 seconds and immersion for 5 seconds in the insecticide solution. A complete randomize design with 4 treatments, 4 repetitions per treatment and 25 individuals per experimental unit was used. Mortality was evaluated at 1, 3 and 7 day post application. Values expressed in percentage were normalized by Bliss angular transformation and then subjected to Andeva and Snk test for mean separation. The study suggested that sulphur, mineral oil and spinosad sprayed on P. flavidulus have a significant effect on the mortality of the wasp, meanwhile, in the immersion method the insecticides produce the mortality of all the wasps since they didn’t had the gas exchange necessary for their survival. For C. montrouzieri the sprayed product that most affect is sulphur followed by spinosad. In the immersion method the treatment that produces the most negative effect on the predator is mineral oil followed by sulphur.

Tesis para optar al Grado de Magíster en Ciencias Agropecuarias, Mención Sanidad Vegetal / Las hembras adultas de Pseudococcus viburni Signoret se caracterizan por producir abundantes secreciones cerosas epicuticulares. Los detergentes agrícolas remueven estas ceras, dejándolas vulnerables a patógenos e insecticidas. En el presente trabajo se realizaron ensayos en laboratorio con el detergente agrícola TS-2035®, los insecticidas Lorsban 4E® (clorpirifós 48% p/v), Mycotrol® (Beauveria bassiana Vuillermin 11,3% p/v), y el hongo entomopatógeno Metarhizium anisopliae Sorokin. Los tratamientos consistieron en la aspersión del detergente en concentraciones en escala logarítmica y un testigo (agua destilada), sobre 20 de estos insectos, en placas Petri, con cuatro repeticiones, utilizando una torre de Potter, hasta encontrar una concentración que no causó mortalidad significativa (0,001% v/v). Además, se procedió a encontrar la concentración letal 50 (CL50) de cada insecticida solo y con esta concentración de detergente, desde la dosis recomendada y disminuyendo en escala logarítmica hasta en cuatro órdenes de magnitud. La mortalidad de los insectos fue evaluada a las 24, 72 y 144 h post exposición. Bajo estas condiciones, la adición de detergente disminuye significativamente la CL50 de Lorsban y M. anisopliae en todos los tiempos evaluados, en cambio, con Mycotrol, ésta disminuyó sólo a las 72 h. Finalmente, según estos resultados, resulta promisorio evaluar estos tratamientos en campo. / Adult females of Pseudococcus viburni Signoret are well known for its production of abundant waxy epicuticular secretions. Agricultural detergents remove these waxes leaving them unprotected and vulnerable to environmental conditions, pathogens and pesticides. In this study, laboratory assays were carried out using the detergent TS-2035®, the pesticides Lorsban 4E® (chlorpyrifos 48% w/v), Mycotrol® (Beauveria bassiana Vuillermin 11,3% w/v), and the entomopathogenic fungi Metarhizium anisopliae Sorokin. The treatments consisted in detergent sprays in logarithmic scale concentrations and a control (distilled water), sprayed on 20 of these insects, placed in Petri dishes, with four replicates, using a Potter tower, until finding a concentration unable to cause a significant mortality (0,001% v/v). Besides, the median lethal concentration (LC50) was calculated for each pesticide, with and without this detergent concentration, starting from the recommended dose and decreasing it, in logarithmic scale, up to four orders of magnitude. The insect mortality was assessed at 24, 72 and 144 h postexposure. Under these conditions, the addition of detergent significantly decreases LC50 of Lorsban and M. anisopliae in all times evaluated, however, with Mycotrol it decreased only at 72 h. Finally, according to these results, it is promising to evaluate these treatments in field assays.

Tesis para optar al grado de magister en ciencias agropecuarias mención sanidad vegetal / Hasta hace no muchos años la granada (Punica granatum) en Chile era considerado un cultivo marginal, sin embargo, en los últimos años ha tomado relevancia debido a que es uno de los alimentos que podrían considerarse como un alimento funcional debido a sus propiedades, ya que sus frutos se caracterizan por ser ricos en antioxidantes, minerales y vitaminas. Además, el cultivo representa una alternativa en condiciones marginales y con baja oferta hídrica. Como consecuencia de ello, la superficie cultivada en el país entre 2007 y 2011 se estima se quintuplicó. Uno de los objetivos principales de la producción es la exportación de fruta fresca, la que alcanzó entre 2008 - 2009 a 1.647 toneladas, siendo su principal destino Europa. Sin embargo, ha habido gran cantidad de rechazos en lugares de destino por partidas infestadas con el chanchito blanco de la vid (Pseudococcus viburni), una plaga cuarentenaria de difícil control. Por lo tanto, se estima que para llevar a cabo un manejo racional del cultivo, es necesaria la implementación de una estrategia de manejo integrado de la plaga (MIP). Antes de ello, es necesario tener un sistema de seguimiento y conocer la fenología y dinámica de esta plaga, para lo cual se evaluaron periódicamente diferentes métodos de muestreo: trampas de cartón corrugado, trampas doble adhesivas, y revisión de follaje y frutos. También se propuso para su control la utilización de productos alternativos (dos detergentes y un entomopatógeno) a los insecticidas convencionales para el manejo de la plaga durante el otoño. Finalmente durante la etapa de postcosecha se evaluaron inmersiones de la fruta en dos concentraciones de detergente (0 – 1% v/v), con dos temperaturas (15 ± 2 - 47 ± 2 °C), pH (5,5 – 8,5) y tiempos de exposición (6 – 15 min).

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.

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.