It has been argued that organic farming sustains a higher biodiversity than conventional farming. This might promote the ecosystem services that exist in agricultural landscapes such as pollination and pest control. Here, I examined the effect of farming system (organic vs. conventional) with respect to the time since farming system transition, landscape heterogeneity and plant richness on pollinating and predatory insects. In total, data from 30 farms were used, of which 20 were organic and 10 were conventional. The data were analyzed using general linear models and model averaging. The results show that insect groups responded differently to various factors. Pollinators were more sensitive to landscape complexity, showing an increase of abundance and species richness with an increased heterogeneity. Predators on the other hand reacted to farming system, where there was an increase in abundance and species richness on organic farms.

Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.

Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.

Paropsis atomaria Olivier (Coleoptera: Chrysomelidae: Paropsini), is a major pest of commercially grown eucalypts in South-East Queensland. Current management of paropsine beetles involves regular inspection and the application of chemical sprays if defoliation is severe. However, non-chemical control of plantation pests is highly desirable given the requirement to certify forest practices for sustainability, and community concerns over the use of pesticides. One way of reducing pesticide use is through conservation biological control, which requires detailed knowledge of the life history of the pest and its natural enemies. This thesis documents aspects of P. atomaria phenology, including life tables, sex ratios and damage estimates; identifies the predators, parasites, and egg and larval parasitoids of P. atomaria; and examines the ecology of the most promising natural enemy, Neopolycystus Girault sp. (Hymenoptera: Pteromalidae) in South-East Queensland. P. atomaria adults are active from September until April and can complete up to four generations in a season. Field mortality between egg and fourth instar larvae is approximately 94%. A large proportion of this mortality can be attributed to natural enemies. The most abundant predators in eucalypt plantations were spiders, comprising 88% of all predators encountered. Egg parasitoids exerted the greatest influence on P. atomaria populations, emerging from around 50% of all egg batches, and were responsible for mortality of almost one third of all eggs in the field. Only about one percent of larvae were parasitised in the field, in contrast to paropsine pests in temperate Australia, where egg parasitism rates are low and larval parasitism rates high. Neopolycystus sp. was the only primary parasitoid reared from P. atomaria eggs, along with three hyperparasitoid species; Baeoanusia albifunicle Girault (Encyrtidae), Neblatticida sp. (Encyrtidae) and Aphaneromella sp. (Platygasteridae). This is the first record of B. albifunicle hyperparasitising Neopolycystus spp. B. albifunicle emerged from one-third of all parasitised egg batches and could pose a potential problem to the efficacy of Neopolycystus sp. as a biological control agent. However, within egg batches, hyperparasitoids rarely killed all Neopolycystus sp. with only 9% of hyperparasitised egg batches failing to produce any primary parasitoids. Total field mortality of P. atomaria through direct and indirect effects of parasitism by Neopolycystus sp. was 28%. The proportion of egg batches parasitised increased with exposure time in the field, but within-batch parasitism rate did not. In general, there was no significant correlation between parasitism rates and distance from landscape features (viz. water sources and native forest).

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Thesis (D. Min.)--St. Vladimir's Orthodox Theological Seminary, 2005. / Abstract. Includes bibliographical references (leaves 93-96).

Thesis (D. Min.)--St. Vladimir's Orthodox Theological Seminary, 2005. / Abstract. Includes bibliographical references (leaves 93-96).

Made available in DSpace on 2015-03-26T13:30:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 201955 bytes, checksum: b7feb61f85a580ed3fecb66929a142b9 (MD5) Previous issue date: 2008-09-29 / Agropalma - Cia. Refinadora da Amazônia / The dende tree (Elaeis guineensis Jacq.) comes from Africa (Guiné-Bissau), and it was introduced in America during the XV century. In Brazil, its introduction occurred in Bahia, a northeast state, and the expansion of its plantation to a commercial level began in 1967. Any factor which interferes in the productivity of dende has to be considered since its growing importance in Brazil, especially in the new culture poles in the Northern states. Insects which are plagues represent one of the major phytosanitary issues of dende, and it has more or less importance according to where it occurs, according to the climate variability, flora and fauna surrounding them. The worst leaf eaters in the state of Pará are Brassolis sophorae, Opsiphanes invirae (Lepidoptera: Nymphalidae) and Sibine sp. (Lepidoptera: Limacodidae). The aim of the present study was to identify, in the family level, genera and or species, entomophagus insects (parasits e predators) and entomophagus organisms (bacterias, virus and or nemathoids) of leaf eater lepdopterus in the dende tree system, giving background to biological control programs. To do so, it is necessary to identify the agents of natural biological control and to understand the population dynamics and also the biology of these species in the dende ecosystem. This study took place in two different periods, low and high precipitation, in the plantation of Agropalma farms in the city of Tailândia, southeast of the state of Para. Parasited catterpilars were collect from the field and taken to the phytosanitary laboratories of Agropalma and the laboratories of Entomology of Embrapa Amazonia Oriental, in Belém, the capital of Para. Pupas and caterpillars were kept in transparent plastic recipients, individually in cameras type B.O.D. under 27ºC ± 1ºC, 75 ± 10% UR and 12 hours photo phase, until the outcome of parasites. The samples were set up and or put inside 70% alcohol before they were taken to be identified. The catterpilars infected by fungus or virus were frozen inside plastic bags under -20ºC, after they were separeted according to the kind of host and the area where they were found. Then they were sent to be identified in the Federal University of Viçosa. There were thirty five different species taken to be identified by taxonomists, among them 28 species of 18 genus in 10 families of the benefitious entomofauna and 3 genus of fungus and 4 species of plagues infected by virus. From those samples, twelve were identified in the species level and one is still unidentified. Special importance has to be given to some species of the Conuragenera once they present high fecundity and short life cycle; Cotesia specie, with wide use in biological control programs around the world and Alcaeorrhynchus grandis (Heteroptera: Pentatomidae), which decrease the occurrence of leaf eater caterpillars and entomopathogenes agents, which can cause high infection rates in plague lepdopterus. The results show a great potential of use in biological control of MIP in dende farms. / O dendezeiro (Elaeis guineensis Jacq.) é originária da África (Guiné-Bissau), e foi introduzida no continente americano a partir do século XV. No Brasil, sua introdução se deu no estado da Bahia e a expansão do seu cultivo em escala comercial a partir de 1967. Qualquer fator que interfira na produtividade da dendeicultura é importante em razão da sua crescente expressão no Brasil, especialmente nos pólos emergentes de cultivos na região Norte. Insetos-praga representam um dos maiores problemas fitossanitários do dendezeiro, com maior ou menor importância dependendo do local de sua ocorrência, da variabilidade climática e da flora e fauna existentes. Desfolhadores mais danosos no estado do Pará são Brassolis sophorae, Opsiphanes invirae (Lepidoptera: Nymphalidae) e Sibine sp. (Lepidoptera: Limacodidae). O objetivo foi identificar, ao nível de família, gênero e/ou espécie, insetos entomófagos (parasitóides e predadores) e organismos entomopatógenos (bactérias, vírus e/ou nematóides) de lepidópteros desfolhadores no agroecossistema do dendezeiro, fornecendo subsídios para a realização de programas de controle biológico. Para isto, torna-se necessário identificar os agentes do controle biológico natural e entender dinâmicas populacionais e a biologia dessas espécies no agroecossistema do dendê. Este trabalho foi realizado em duas épocas diferentes, baixa e alta precipitação, nos plantios das fazendas do Complexo AGROPALMA no município de Tailândia, sudeste do estado do Pará. Lagartas parasitadas foram coletadas em campo e transportadas para os laboratórios de fitossanidade da Agropalma e de Entomologia da Embrapa Amazônia Oriental, em Belém, Pará. Pupas e lagartas foram individualizadas em potes plásticos transparentes em câmara tipo B.O.D. à 27ºC ± 1ºC, 75 ±10% UR e fotofase de 12 horas, até a emergência de parasitóides. Os exemplares foram montados e ou colocados em álcool 70% e enviados para identificação. Lagartas infectadas por vírus e fungos foram congeladas à -20ºC em sacos plásticos e separadas por espécie de hospedeiro e área encontrada e enviadas para identificação na Universidade Federal de Viçosa. Trinta e cinco espécies foram coletadas e levadas a taxonomistas para identificação, sendo 28 espécies de 18 gêneros em 10 famílias da entomofauna benéfica mais 3 gêneros de fungos e 4 espécies pragas infectadas por vírus. Doze dessas foram identificadas ao nível de espécie com pelo menos uma espécie ainda não descrita. Destaque para algumas espécies do gênero Conura por apresentar alta fecundidade e ciclo de vida curto; espécies de Cotesia com ampla utilização em programas de controle biológico em todo o mundo e Alcaeorrhynchus grandis (Heteroptera: Pentatomidae), que controlam surtos de lagartas desfolhadoras e os agentes entomopatogênicos, que causam altas taxas de infecções em lepidópteros-praga, mostram potencial para serem usados em programas de controle biológico no MIP do dendê.

Made available in DSpace on 2014-06-11T19:25:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-29Bitstream added on 2014-06-13T19:47:21Z : No. of bitstreams: 1 varella_ac_me_jabo.pdf: 286252 bytes, checksum: 73921cba4ab7c058f7da78ddc42e5c3e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo desse trabalho foi caracterizar a dinâmica dos fatores de mortalidade de ovos e larvas (1o e 2o ínstares) de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), e avaliar o impacto de liberações de Telenomus remus Nixon (Hymenoptera: Platygastridae) na supressão da população dessa praga. Tabelas de vida ecológicas para ovos e larvas (1o e 2o ínstares) de S. frugiperda foram construídas em agroecossistema de milho, com e sem liberações inundativas do parasitoide, nas safras úmidas e secas de 2010 e 2011. A mortalidade total de ovos variou entre 73 e 81%. Os maiores valores de mortalidades marginal e insubstituível, nas áreas com e sem liberações, foram causadas por inviabilidade e deslocamento nas safras úmidas e por inviabilidade e predação nas safras secas. Parasitoides não causaram mortalidade significativa nas populações de ovos e larvas e as liberações de T. remus não aumentaram a mortalidade de ovos. Mais de 95% das larvas morreram devido à predação, deslocamento pela chuva ou ballooning e a mortalidade total causada por esses fatores foi amplamente insubstituível. Quando as mortalidades de ovos e larvas foram analisadas conjuntamente, a mortalidade de larvas substituiu quase que completamente a mortalidade de ovos. Os resultados indicaram que maiores reduções nas populações de S. frugiperda podem ser conseguidas aumentando-se a mortalidade dos ínstares iniciais do estágio larval / The aim of this study was to characterize the dynamics of mortality factors affecting initial immature developmental stages (eggs and 1st. and 2nd. instar larvae) of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), and assess the impact of Telenomus remus Nixon (Hymenoptera: Platygastridae) releases on pest population suppression. Life tables for egg and early larval stages of S. frugiperda were developed in maize fields with and without augmentative parasitoid releases, in the wet and dry seasons of 2010 and 2011. Total egg mortality did not vary considerably among years and ranged from 73 to 81%. The highest egg marginal mortality and irreplaceable mortality in both release and non-release fields was due to inviability and dislodgement in wet seasons and inviability and predation in dry seasons. Parasitoids did not cause significant mortality in egg or early larval stages and the releases of T. remus did not increase egg mortality. A large percentage of early larvae (> 95%) died from predation, dislodgment by rainfall or ballooning and total mortality due to these factors was largely irreplaceable. When considering egg and larval mortality together, early larval mortality would almost completely replace egg mortality if the egg mortality factors were removed. Results indicate that a greater effect in reducing generational survival may be achieved by adding mortality to the early larval stage of S. frugiperda

Made available in DSpace on 2014-06-11T19:35:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-04Bitstream added on 2014-06-13T19:05:41Z : No. of bitstreams: 1 celoto_fj_dr_ilha.pdf: 960631 bytes, checksum: 5b6f25a5fd94acb59a226624a376c078 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cultura dos citros é uma das principais atividades do agronegócio brasileiro, gerando divisas na ordem de US$ 2,3 bilhões com geração de aproximadamente 400 mil empregos diretos. Nas últimas décadas a citricultura brasileira apresentou um cenário evolutivo ascendente quanto à ocupação territorial e produtividade, posicionando-se como a maior citricultura do mundo. Entretanto os desafios fitossanitários são enormes e a introdução de novas pragas e doenças é freqüente em citros. Dentre os problemas fitossanitários, a leprosedos- citros, transmitida pelo ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) é ainda uma das mais sérias, considerando o custo de controle que pode atingir 24% do custo total e pode ocasionar perdas de 35 a 70% na produção. A leprose é uma das poucas doenças virais cujo controle é feito com sucesso pelo do controle químico do vetor. Para que o controle químico seja menos impactante e a necessidade do uso de acaricidas reduzida, a seletividade dos defensivos agrícolas aos inimigos naturais das pragas é de grande importância. Neste contexto um novo acaricida foi introduzido para uso no manejo do ácaroda- leprose dos citros. Trata-se de uma nova molécula de nome comum etoxazol, pertencente a um novo grupo químico (Difenil oxazolina). Seu mecanismo de ação ocorre através da inibição do processo normal da ecdise, atividade ovicida e efeito esterilizante sobre fêmeas adultas. O objetivo deste trabalho foi avaliar a atividade do acaricida etoxazol isoladamente e em mistura com o acaricida adulticida propargito, no controle do ácaro-da-leprose, B. phoenicis e sua seletividade aos artrópodes benéficos na cultura do citros em condições de campo e laboratório. Para tanto foram conduzidos os seguintes estudos: 1) atividade dos acaricidas no controle do ácaro B. phoenicis em campo; 2) avaliação da seletividade... / The citrus crop is one of the most important activities of the Brazilian agriculture, generating exchange value in the order of US$ 2.3 billion with generation of approximately 400 thousand direct jobs. In the last decades the Brazilian citriculture presented ascending evolutionary scenery as for the territorial occupation and productivity, being positioned as the largest citriculture of the world. However the phytossanitary challenges are enormous and the introduction of new pests and diseases are frequent in citrus. Among the a lot of pests of the culture, the citrus leprosis, transmitted by the Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) it is still one of the most important, considering the control cost that can reach 24% of the total cost and it can ocasonar losses from 35 to 70% in the production. The citrus leprosis is one of the few diseases turn whose control is done with success through the chemical control of the vector. For the chemical control to be less impactant and it reduced need, the selectivity of the acaricides to the natural enemies of the pests is of great importance. In this context a new acaricide was introduced for use in the integrated pest management of citrus. It is a new molecule of common name etoxazole, belonging to a new chemical group (Diphenyloxazoline). It action way happens through the inhibition of the normal process of the ecdise, ovicidal activity and esterilizant effect on adult females. The objective of this work was to evaluate the activity of the acaricida etoxazole separately and in mixture with the adulticide acaricide propargite, in the control of the citrus leprosis mite, B. phoenicis and it selectivity to the beneficial arthropods in the citrus crop in field conditions and laboratory and for so much the following studies were driven: 1) activity of the acaricides in the control of the B. phoenicis mite in field; 2) evaluation... (Complete abstract click electronic access below)