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Scarabaeidae) have shown that the fungus has the potential to infect and kill non target species, at least in the laboratory (Devotto et al., 2003). The studies mentioned above were conducted on selected beneficial species, but less work has been done to compare the effects of D. pallens control strategies at the community level. This knowledge and adequate assessment of the ecological risks of B. bassiana are needed before scaling to extensive use, to prevent unintended adverse effects on the grassland ecosystem functioning, including natural pest control. Regardless of the habitat or ecosystem, arthropods contribute well over half of the metazoan species (Dennis, 2003), playing different roles, including herbivore regulation, nutrient cycling and other ecosystem processes. In relatively simple systems such as grasslands, arthropods even have a higher preponderance. The aim of this study was to compare the effects of conventional and biological control of D. pallens on the grassland arthropod community of South Chile. We designed two experiments to test the hypothesis that B. bassiana biopesticide would be less disruptive to the ground-dwelling arthropofauna than the insecticide lambda-cyhalothrin. Materials And Methods. Sites and environmental data. Two trials were conducted: one in winter and one in spring. The winter trial was conducted on a farmer’s field near Osorno, Chile (40º35’ S, 73°10' W), from July to September 2003. Plant cover was composed of hybrid ryegrass (Lolium perenne x Lolium multiflorum; 80-90 %) and broad-leaf species, including Plantago spp and Cyperaceae (
Fungus. Beauveria bassiana strain QU-B931 was isolated from a field-collected larva of Dalaca pallens in 1998, using a semi-selective media described by Alves et al. (1998), based on Chase et al. (1986). Mycelium and spores were cryopreserved at –196 °C and held at the Entomopathogenic Organisms Collection (Instituto de Investigaciones Agropecuarias, Chillán, Chile) and mass-reared in rice bags. Spores were harvested, dehydrated and stored in vacuum. Germination assays were done in both experiments as follow: a sample of the tank mix was taken. In the laboratory, 0.5 ml of the tank sample were spread on 2% agar plates. Plates were held in darkness for 48 h and germination of the spores was recorded at 24 and 48 h counting at least 100 spores in each plate under microscope. Germination percentage was calculated as (number of germinated spores/ total number of spores) x 100. 24 and 48 h counts were averaged as they yielded similar estimates. These analyses gave >80% viability in both cases. Procedures. Three sites were established for the winter experiment: control site (0.5 ha); B. bassiana site (1 ha) and λ-cyhalothrin (alpha-cyano-3-phenoxybenzyl 3-(2-chloro-3,3,3- trifluoropropenyl)-2,2-dimethylcyclopropanecarboxylate) site (1 ha). Sites were 100-150 apart each other and surrounded by grassland. Treatments were applied on July 24, 2003, a cloudy day, between 09:00 – 13:00 h. Ten grams of conidia were mixed with non ionic detergent (Down, Procter&Gamble, Buenos Aires, Argentina) and suspended in 200 l of water. This suspension was sprayed on the B. bassiana site (10 12 spores per ha), hereafter referred as B. bassiana treatment. Lambda-cyhalothrin (ZERO 5 EC, ANASAC, Santiago, Chile) was applied according to the procedure described above (but non ionic detergent) at label rate for Dalaca sp. control (7.5 g A.I. per ha). In the spring experiment, twelve plots (30 x 30 m) were established in the 4 ha field, delimited by wooden sticks. Four plots were assigned to each treatment at random and four plots remained as control. Spores or λ-cyhalothrin were sprayed on October 15, 2003, as described above, under clear skies and no wind, between 18:00 and 20:00 h. The first post- treatment rain fell the following morning. No additional plant protection products were applied. Spray deposition was assessed in the spring experiment: soil and foliage samples were taken and colony forming units (CFUs) per square centimeter of leaf or gram of soil 106
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UNIVERSIDAD AUSTRAL DE CHILE FACULT
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DIVERSIDAD Y CONTROL BIOLÓGICO DE
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ÍNDICE DE CONTENIDOS INTRODUCCIÓN
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4.- CAPÍTULO CUARTO: ANÁLISIS DE
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CAPÍTULO I. INDICE DE CUADROS Tabl
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CAPÍTULO I. ÍNDICE DE FIGURAS Fig
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Figure 5. Rarefaction curves for th
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ABSTRACT About 10% of Southern Chil
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Sin embargo, a pesar de esta percep
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preeminencia de esta idea ha sido e
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niveles tróficos completos o grand
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Se ha propuesto diversos enfoques p
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El control de esta especie se reali
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con la consiguiente pérdida o dism
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4. Numerosos estudios se concentran
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1.- CAPÍTULO PRIMERO: DIVERSIDAD G
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sample, showing the potential use o
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and put it in a phylogeographical p
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centrifugation and supernatant was
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(Schneider and Excoffier, 1999; Alt
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All the putative populations showed
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strongly influenced by insect host
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supported a geographical sub-divisi
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Neuveglise C, Brygoo Y, Vercrambe B
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Table 1. Environmental data for the
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B907 Poike 27º 06' 109º 21' Easte
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B606 Lago Icalma 38º 50' 71º 20'
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Figure 1. NJ tree of the B fragment
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Figure 2. Haplotype tree inferred f
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Figure 4. Mismatch distributions of
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Figure 5. Haplotype diversity in th
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Table 6. Analyses of molecular vari
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Table 8. Pairwise differentiation e
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CONSERVATION BIOLOGICAL CONTROL OF
Page 69 and 70: Introduction. In last decades, mode
Page 71 and 72: a dose of 10 12 spores per ha was s
Page 73 and 74: aerea were very low at 1 and 30 day
Page 75 and 76: explanation than no toxicity of the
Page 77 and 78: fields that are sprayed with pestic
Page 79 and 80: affected species, when present, whe
Page 81 and 82: Kiss, B., Samu, F., 2000. Evaluatio
Page 83 and 84: Wilby, A., Villareal, S., Lan, L.,
Page 85 and 86: ARANEAE Gnaphosidae 253 54 % Lycosi
Page 87 and 88: Activity density (individuals per p
Page 89 and 90: NON-TARGET EFFECTS OF Dalaca pallen
Page 91 and 92: same percentage of mortality on lar
Page 93 and 94: Treatments were applied on 15 Octob
Page 95 and 96: (Departamento de Producción y Sani
Page 97 and 98: Predators. Data set I. The principa
Page 99 and 100: predators extracted from soil cores
Page 101 and 102: particularly carabids. Most of the
Page 103 and 104: the consistent results allow us to
Page 105 and 106: Kenmore, P.E., Cariño, F., Perez,
Page 107 and 108: Traugott, M., Strasser, H. and Prie
Page 109 and 110: Table 2. Significance of treatment
Page 111 and 112: Figure 1. Persistence of B. bassian
Page 113 and 114: Figure 3. Principal response curve
Page 115 and 116: Figure 5. Principal response curve
Page 117 and 118: RESPONSE OF GRASSLAND SOIL ARTHROPO
Page 119: Introduction. Declining diversity h
Page 123 and 124: Data collection. The abundance and
Page 125 and 126: N is the total number of individual
Page 127 and 128: catches), while dominant species re
Page 129 and 130: knowledge of South Chile grassland
Page 131 and 132: Dennis, P., 2003. Sensitivity of up
Page 133 and 134: invertebrates. In: IFOAM 2000 The W
Page 135 and 136: Figure 2. Estimated numbers Beauver
Page 137 and 138: Figure 4. Effects of B. bassiana an
Page 139 and 140: Figure 6. Rarefaction curves for th
Page 141 and 142: genética coincide con la zona de m
Page 143 and 144: Crosonychus viridis, Trechisibus an
Page 145 and 146: depredadores de lepidópteros, en l
Page 147 and 148: Respuesta a nivel de grupos funcion
Page 149 and 150: La conservación de los herbívoros
Page 151 and 152: Se ha propuesto que esta hipotétic
Page 153 and 154: En esta línea de razonamiento, las
Page 155 and 156: suceda en sistemas simples con poco
Page 157 and 158: BIBLIOGRAFIA Alarcón R. 1997. Resp
Page 159 and 160: isolated from the European cockchaf
Page 161 and 162: Hardin MR, Benrey, M Coll, WO Lamp,
Page 163 and 164: Lockwood JA, 1993. Environmental is
Page 165 and 166: Pimentel D, C Glenister, S Fast y D
Page 167 and 168: Swift MJ, J Vandermeer, PS Ramakris
Page 169 and 170: Zelada SH, 1998. Rol de la franja d
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Anexo 1. Índices de severidad de l
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Anexo 3. Capturas provenientes de l
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Page 177:
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