Browsing by Author "Zaviezo, Tania"

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    A new species of Pseudococcus (Hemiptera: Pseudococcidae) belonging to the "Pseudococcus maritimus" complex from Chile: molecular and morphological description
    (MAGNOLIA PRESS, 2011) Correa, Margarita; Aguirre, Carlos; Germain, Jean Francois; Hinrichsen, Patricio; Zaviezo, Tania; Malausa, Thibaut; Prado, Ernesto
    A new species of mealybug from Chile, Pseudococcus meridionalis Prado sp. n., is described and illustrated based on the morphological and molecular characterization of adult females. This species belongs to the "Pseudococcus maritimus" complex and displays a wide host plant range, including Japanese pear, persimmon, pomegranate, pear and grape.
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    Chrysanthemyl 2-acetoxy-3-methylbutanoate: the sex pheromone of the citrophilous mealybug, Pseudococcus calceolariae
    (PERGAMON-ELSEVIER SCIENCE LTD, 2010) El Sayed, Ashraf M.; Unelius, C. Rikard; Twidle, Andrew; Mitchell, Vanessa; Manning, Lee Anne; Cole, Lyn; Suckling, David M.; Fernanda Flores, M.; Zaviezo, Tania; Bergmann, Jan
    Headspace volatiles collected from virgin females of the citrophilous mealybug, Pseudococcus calceolariae, contain three Compounds not present in the headspace of control samples. The main female-specific compound is identified as[2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methyl 2-acetoxy-3-methylbutanoate (chrysanthemyl 2-acetoxy-3-methylbutanoate). The other two compounds are identified as [2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methanol (chrysanthemol) and [2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methyl 2-hydroxy-3-methylbutanoate (chrysanthemyl 2-hydroxy-3-methylbutanoate). Traps baited with 100 mu g and 1000 mu g of chrysanthemyl 2-acetoxy-3-methylbutanoate captured 4- and 20-fold more males than traps baited with virgin females. (C) 2009 Elsevier Ltd. All rights reserved.
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    Diversity and foraging activity of bats in cultivated and uncultivated areas in agroecosystems of a Mediterranean-climate hotspot
    (2019) Muñoz, Alejandra E. ; Ossa, Gonzalo ; Zaviezo, Tania ; Bonacic, Cristián
    Bats are one of the least-studied vertebrate groups in Chile. We sampled six fruit farms in the Mediterranean-climate zone and three in a semiarid zone during 2015 and 2016, respectively. We assessed if activity (passes) and foraging (feeding buzzes) of bat species differed between cultivated and uncultivated intra-farm habitats. We found six bat species, all threatened and insectivorous. Tadarida brasiliensis was the most frequently recorded species. We found more activity and foraging in uncultivated than cultivated habitats in total, although the opposite trend was observed during springtime in semiarid region. More than a third of the bat passes were feeding buzzes in both habitats, suggesting the potential service to agriculture. Further investigation is needed to promote conservation of bats and their integration as biocontrols in agroecosystems in Chile.
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    Ecoinformatics for Integrated Pest Management: Expanding the Applied Insect Ecologist's Tool-Kit
    (ENTOMOLOGICAL SOC AMER, 2011) Rosenheim, Jay A.; Parsa, Soroush; Forbes, Andrew A.; Krimmel, William A.; Law, Yao Hua; Segoli, Michal; Segoli, Moran; Sivakoff, Frances S.; Zaviezo, Tania; Gross, Kevin
    Experimentation has been the cornerstone of much of integrated pest management (IPM) research. Here, we aim to open a discussion on the possible merits of expanding the use of observational studies, and in particular the use of data from farmers or private pest management consultants in "ecoinformatics" studies, as tools that might complement traditional, experimental research. The manifold advantages of experimentation are widely appreciated: experiments provide definitive inferences regarding causal relationships between key variables, can produce uniform and high-quality data sets, and are highly flexible in the treatments that can be evaluated. Perhaps less widely considered, however, are the possible disadvantages of experimental research. Using the yield-impact study to focus the discussion, we address some reasons why observational or ecoinformatics approaches might be attractive as complements to experimentation. A survey of the literature suggests that many contemporary yield-impact studies lack sufficient statistical power to resolve the small, but economically important, effects on crop yield that shape pest management decision-making by farmers. Ecoinformatics-based data sets can be substantially larger than experimental data sets and therefore hold out the promise of enhanced power. Ecoinformatics approaches also address problems at the spatial and temporal scales at which farming is conducted, can achieve higher levels of "external validity," and can allow researchers to efficiently screen many variables during the initial, exploratory phases of research projects. Experimental, observational, and ecoinformatics-based approaches may, if used together, provide more efficient solutions to problems in pest management than can any single approach, used in isolation.
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    Effects of habitat loss and fragmentation on the abundance and species richness of aphidophagous beetles and aphids in experimental alfalfa landscapes
    (CZECH ACAD SCI, INST ENTOMOLOGY, 2008) Grez, Audrey A.; Zaviezo, Tania; Diaz, Sandra; Camousseigt, Bernardino; Cortés Hinojosa, Galaxia Andrea
    In agro-ecosystems, habitat loss and fragmentation may alter the assemblage of aphidophagous insects, Such as foliar-foraging (coccinellids) and ground-foraging predators (carabids), potentially affecting intraguild interactions. We evaluated how habitat loss (0, 55 and 84%), fragmentation (1, 4 and 16 fragments) and their combination affected the abundance and species richness of coccinellids and carabids, and aphid abundance, both in the short-term (summer: December to February) and over a longer time span (autumn: March to May), when different demographic mechanisms may participate. We created four types of 30 x 30 in patches (landscapes) in which alfalfa was grown: Control (IF - 0%, 30 x 30 ill patch of alfalfa with no fragmentation or habitat loss), 4F - 55% (4 alfalfa fragments, with 55% total habitat loss), 4F - 84% (4 alfalfa fragments, with 84% total habitat loss), and 16F - 84% (16 alfalfa fragments, with 84% total habitat loss). Each landscape type was replicated five times. Insects were sampled by sweep-netting and pitfall traps, from December (summer) to May (autumn). Total abundance and species richness of carabids, in the short-term, was highest in the 1 6F - 84% landscapes. Total abundance of adult coccinellids was similar among landscapes, but at the species level Hyperaspis sphaeridioides, in the short-term, and Adalia bipunctata, in the long-term, had their highest densities in fragments within landscapes with high habitat loss (84%), independently of habitat fragmentation. Species richness in the long-term was higher in the landscapes with 84% habitat loss. Among aphids, in the long term Aphis craccivora was less abundant in landscapes with high habitat loss and fragmentation (16-84%), while Therioaphis trifolii showed the opposite trend. These results suggest that habitat loss and fragmentation may increase the density and diversity of aphidophagous insects, while their effects oil aphids are more variable.
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    Effects of habitat loss, habitat fragmentation, and isolation on the density, species richness, and distribution of ladybeetles in manipulated alfalfa landscapes
    (WILEY, 2006) Zaviezo, Tania; Grez, Audrey A.; Estades, Cristian F.; Perez, Astrid
    1. Habitat loss and fragmentation are the main causes of changes in the distribution and abundance of organisms, and are usually considered to negatively affect the abundance and species richness of organisms in a landscape. Nevertheless, habitat loss and fragmentation have often been confused, and the reported negative effects may only be the result of habitat loss alone, with habitat fragmentation having nil or even positive effects on abundance and species richness.
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    Influence of mealybug (Pseudococcus spp.)-infested bunches on wine quality in Carmenere and Chardonnay grapes
    (WILEY, 2012) Bordeu, Edmundo; Troncoso, Diego O.; Zaviezo, Tania
    This study evaluated the effects of processing grape with different proportions of mealybug-infested bunches in wine quality in cultivars Chardonnay and Carmenere. No differences in chemical composition of musts were found. Basic chemical composition for white and red wines was similar. In both cultivars total polyphenols decreased as the proportion of infested bunches increased, from 266 to 239 (mg L-1 gallic acid) in Chardonnay and 2124 to 1820 in Carmenere. The same trend was observed in Carmenere for anthocyanins and tannins, by spectrophotometry and high performance liquid chromatography. Dimethyl amino cinnamaldehyde index in Carmenere went from 28.6 in wines 100% healthy bunches to 22.0 for the 100% infested, and tannin galoilation went from 3.85 to 0.74%. Sensory analysis showed that wines with larger proportion of infested grapes were associated with negative descriptors and lower quality. These results show that mealybugs have the potential of negatively impacting wine quality and this deserves further attention.
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    Migration of coccinellids to alfalfa fields with varying adjacent vegetation in Central Chile.
    (2010) Grez, Audrey A.; Torres, Constanza; Zaviezo, Tania; Lavandero, Blas; Ramírez, Marcelo
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    Native flower strips increase visitation by non-bee insects to avocado flowers and promote yield
    (2021) Muñoz, Alejandra E. ; Plantegenest, Manuel ; Amouroux, Paul ; Zaviezo, Tania
    Pollination is an essential ecosystem service for pollinator-dependent crops and plant communities. Apis mellifera L. is by far the most commonly used species to obtain this service in agriculture. However, there is growing evidence of the importance for crop yields of the service provided by wild bees and non-bee insect pollinators. Establishing flower resources in agricultural landscapes is a management practice that can increase insect pollinator populations and improve crop yields. We established perennial native flower strips (NFS) in four avocado orchards in central Chile during autumn 2017. We monitored flower visitors and counted newly formed fruits in avocados near and far from NFS in spring 2019, to assess flower visitor groups, flower visitation rates and fruit numbers. Only A. mellifera visited avocado flowers within bees, whereas both the managed A. mellifera and wild bees were the main visitors to the NFS. NFS increased visitation rates to adjacent avocado of flies, and with a trend for the sum of all non-managed flower visitors (i.e. excluding A. mellifera). However, there were no differences in the rates of A. mellifera visitation to avocados near and far from NFS. Avocado fruit numbers were higher among avocados near NFS than among those farther away. This difference could be due to better pollination by the increased visits to avocado flowers by flies or other wild insects. Therefore, NFS could contribute to crop fruit number, as well as conservation of native flora, wild bees and non-bee pollinators on fruit farms in the "Central Chile" biodiversity hotspot. (C) 2021 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.
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    Native flowering shrubs promote beneficial insects in avocado orchards
    (2021) Muñoz, Alejandra E. ; Amouroux, Paul ; Zaviezo, Tania
    Flower strips can promote and conserve beneficial insects in agroecosystems. Knowing which groups are favoured and which plant traits affect visitation rates by beneficial insects is important for the design of plant strips.
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    Natural enemy communities of aphids in alfalfa fields assessed through video recordings of sentinel cards in scenarios of contrasting aphid abundance
    (2024) Grez, Audrey A.; Zaviezo, Tania; Molina, Gabriela
    The first step to better understand the relationship between natural enemy communities and pest control is to know which, when, and how frequently different natural enemies interact with their prey. In alfalfa fields of central Chile, aphids are the most common pests and are consumed by predators such as coccinellids, syrphids, and spiders. In this study, through video recording, we analyzed how natural enemy communities visiting aphid sentinel cards vary between scenarios of low and high abundance of aphids in alfalfa in spring. On 15 occasions, during the day, we monitored the natural enemies visiting cards with sentinel aphids (60 cards per field; total 900) located in fields with high (n = 6) and low (n = 9) aphid abundance. We also analyzed whether the abundance of coccinellid species visiting sentinel cards was related to their abundance in each field. In 750 h of video recording, we found 2749 natural enemies visiting the sentinel cards; 86.2% of them were coccinellids of five species. Total natural enemies and coccinellid visits were three times higher in low than in high aphid abundance scenarios. In contrast, the species richness and diversity of natural enemies and coccinellids visiting cards did not differ between aphid scenarios. The abundance of coccinellids in the field was positively associated with the abundance of coccinellids visiting cards, for the three most abundant species. Our study shows that video recording is useful for identifying changes in the communities of natural enemies of aphids in alfalfa, providing important new insights into trophic interactions in field situations.
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    Primer registro de Goniozus legneri (Hymenoptera: Bethylidae) para Chile.
    (2007) Zaviezo, Tania; Romero, Alda; Castro, David; Wagner, Adrián