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Ecological and behavioral factors associated with monitoring and managing pink hibiscus mealybug (Hemiptera: Pseudococcidae) in the southern USVitullo, Justin Matthew 21 July 2009 (has links)
The pink hibiscus mealybug (PHM), Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) was investigated with regard to damage caused to hibiscus by feeding, dispersal of nymphs, evaluation of management tactics, and the use of sex pheromone based monitoring in southern Florida from 2005 to 2008. Understanding the ability of PHM to locate and colonize new hosts, and the response of hosts is essential to optimized monitoring and management strategies. Investigation of the onset and severity of PHM feeding symptoms by Hibiscus rosa-sinensis L. showed that severity of symptoms differed among cultivars and that PHM were found on plants that did not exhibit feeding symptoms. Aerially dispersing PHM were predominantly first instars. Dispersal occurred with a diel periodicity that peaked between 14:00 and 18:00 h and was significantly influenced by mean wind speed. Initial infestation with 5, 10, or 20 PHM adult females had no significant affect on the number of dispersing individuals captured from hibiscus plants and PHM were captured at 50 m from infested source plants.
The effects of mating disruption, the insecticide (dinotefuran), the parasitoid, Anagyrus kamali (Moursi), and the predator, Cryptolaemus montrouzieri (Mulsant) on PHM on hibiscus plants in screened field cages were evaluated. The total number of mealybugs captured in sticky band and pheromone traps during the study was reduced by dinotefuran and the predator. At the end of the study, the number of nymphs recovered from hibiscus terminals was reduced by the dinotefuran, predator and parasitoid treatments. Field experiments showed that the time of day during which male PHM were captured in pheromone traps in May and September was crepuscular, with most captures occurring from 18:00 to 21:00 h. Significantly more males were captured in traps placed in non-host trees at an elevation of 2 m above the ground than 6 m, and more males were captured in traps placed within host plants than in those 3 m upwind. Pheromone traps placed in hibiscus treated with soil applied dinotefuran or left untreated captured equal numbers of males during the 3 wk prior to treatment and during the 12 wk after treatment. Release of parasitoids at residential sites did not have a significant effect on the total number of males captured in sex pheromone traps over 18 mo. The number of mealybugs found at both parasitoid release and untreated sites were highly variable and corresponded with males captured in sex pheromone traps, as high and low levels of mealybugs corresponded with high and low levels of males captured. The number of males captured in pheromone traps during a two week survey at residential sites in May were a strong predictor of subsequent captures in 2006 (r2 = 0. 712), but not 2007 (r2 = 0.019). The relationship between PHM populations and males captured in sex pheromone traps was influenced by a multitude of factors that can impact the ability of traps to accurately reflect populations at a given location. Pheromone traps have the potential to provide meaningful information towards monitoring and mitigating risk from PHM. The contributions of this dissertation towards optimizing PHM sex pheromone monitoring, as well as facets of PHM monitoring that have yet to be resolved are discussed. / Ph. D.
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Bioecologia e controle biológico da cochonilha-rosada em RoraimaMarcelo Negrini 27 August 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A cochonilha-rosada, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae), é uma praga recém-introduzida no Brasil que ameaça inúmeras culturas, especialmente a fruticultura e plantas ornamentais. Essa praga foi relatada pela primeira vez no Brasil em Roraima e até o momento não existem informações sobre bioecologia e controle desta praga no país. O objetivo desse trabalho foi estudar a biologia e a dinâmica populacional de M. hirsutus e de seus inimigos naturais em Roraima. O trabalho foi conduzido em laboratório para determinação dos parâmetros biológicos de M. hirsutus e em um cultivo de Annona squamosa L. (Anonaceae), para avaliação dos efeitos dos fatores climáticos, do controle biológico e do manejo da cultura sobre sua dinâmica populacional. Maconellicoccus hirsutus pode ter até nove gerações por ano, com 6,5 dias para dobrar sua população em tamanho. O número de fêmeas é cerca de três vezes maior que o de machos. A oviposição foi de 98 ovos/fêmea, com viabilidade de 97%. As populações de M. hirsutus foram maiores durante o período de frutificação e não apresentam correlação com as variáveis climáticas. Os níveis de infestação foram baixos (5,2 %), e isto pode estar relacionado às elevadas taxas de parasitismo (55,4 %) por Anagyrus kamali Moursi (Hymenoptera: Encyrtidae) e a predação por bicho-lixeiro (Chrysopidae). Árvores podadas apresentaram infestações menores que as encontradas em árvores não podadas. Maconellicoccus hirsutus possui elevado potencial biótico em condições de clima seco e quente, entretanto a ação de seus inimigos naturais associados às boas práticas de manejo podem manter baixos os níveis populacionais de M. hirsutus. / The pink hibiscus mealybug, Maconellicoccus hirsutus (Hemiptera: Pseudococcidae), is a pest recently introduced in Brazil threatens numerous crops, especially to orchards and ornamental plants. The first reported of this pest in Brazil was in Roraima, and there was not information about its bioecology and biological control in the country. The objective of this work was to study the biology and the population dynamic of M. hirsutus and of its natural enemies in Roraima. The work was conducted in the laboratory to determine the biological parameters of M. hirsutus and in an orchard of Annona squamosa L. (Anonaceae), to evaluate the effect of the climate, biological control and crop management on its dynamic population. Maconellicoccus hirsutus can have up to nine generations per year, with 6.5 days to double their population size. The number of females is about three times larger than that of males. The oviposition was 98 eggs / female, with viability of 97%. Populations of M. hirsutus were higher during the period of fruiting and it did not correlate with climate variables. The infestation levels were low (5.2%) and can be related to high parasitism rates (55.4%) by por Anagyrus kamali Moursi (Hymenoptera: Encyrtidae) and predation by lacewing (Chrysopidae). Pruned trees were less infested 40.95% lower than those trees not pruned. Maconellicoccus hirsutus has a high biotic potential in dry and warm weather conditions, however its natural enemies associated to a good management practices can maintain the population levels of M. hirsutus low.
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