Publications by authors named "Marcela I Schneider"

Article Synopsis
  • Compatibility studies of insecticides often ignore long-term effects on natural enemies like parasites, focusing mostly on short-term lethal impacts.
  • In a study of different insecticides on the pupae of the parasitoid Diaeretiella rapae, imidacloprid showed significant harm, reducing adult emergence, while spirotetramat and its mixtures only affected the parasitoid at higher doses.
  • The findings suggest that imidacloprid is the most toxic to D. rapae, indicating that its use in pest management should be avoided to protect this potential biological control agent.
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Article Synopsis
  • The study examined the effects of two biorational insecticides, azadirachtin and pyriproxyfen, compared to a neonicotinoid insecticide, acetamiprid, on the Neotropical strain of Eretmocerus mundus.
  • All three insecticides reduced adult emergence and survival, with azadirachtin being the most toxic at its highest recommended concentration.
  • Sublethal effects, such as reproductive capacity, sex ratio, and longevity, were observed, particularly with pyriproxyfen negatively impacting female reproductive capacity in survivors.
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Lethal and sublethal effects of refined soybean oil, imidacloprid, and abamectin on Tamarixia triozae (Burks; Hymenoptera: Eulophidae) were assessed after exposure of the eggs, larvae, and pupae of this parasitoid to three concentrations of these active substances: the LC50 for fourth-instar Bactericera cockerelli (Sulc.; Hemiptera: Triozidae) and 50% and 100% of the minimum field-registered concentration (MiFRC). Soybean oil caused 26-61% mortality in T.

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Compatibility assessments between selective insecticides and the natural enemies of pests are essential for integrated-pest-management programs. Chrysoperla externa and Eriopis connexa are two principal Neotropical predators of agricultural pests whose conservation in agroecosystems requires a toxicity evaluation of pesticides to minimize the impact on those beneficial insects on the environment. The objective of this work was to evaluate the toxicity of the insecticides pyriproxyfen and acetamiprid on C.

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Article Synopsis
  • The study investigates the toxicity of a new insecticide, spirotetramat, on a specific strain of Eretmocerus mundus, comparing its effects to those of the conventional pesticide cypermethrin.
  • Results show that spirotetramat is less harmful to both pupae and adult stages of the parasitoid compared to cypermethrin, which is known to be highly toxic to natural enemies.
  • The insecticide spirotetramat negatively impacted the longevity and survival of the first progeny and reduced overall demographic parameters, highlighting the importance of evaluating pesticides' effects on beneficial organisms in agriculture.
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Endoparasitoids can be killed by host encapsulation, a cellular-mediated host immunological response against parasitism that involves hemocytes aggregation. As a counteracting strategy, many parasitoids can evade this host response through self-superparasitism. The objectives of this study were: 1) to describe the parasitoid Pseudapanteles dignus (Hymenoptera: Braconidae) early immature stages (egg and larva) encapsulation by the host Tuta absoluta (Lepidoptera: Gelechiidae), and 2) to determine the occurrence of self-superparasitism and the rate of escaping to encapsulation of this parasitoid.

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Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action-pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin-were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %).

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Soybean pest control in Argentina is done just by chemical control using broad-spectrum pesticides. Alpaida veniliae (Araneae, Araneidae) is one of the most abundant spider species of the orb web weaver guild in soybean, and it is considered a very important polyphagous predator, attacking different insects' families. The objective of this study was to determine if neurotoxic insecticides commonly used in soybean crops and a new active ingredient registered in Argentina (spinosad) adversely affected survival, prey consumption, mating behaviour, web building and reproductive capacity of A.

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Article Synopsis
  • * The study found that acetamiprid significantly reduces egg hatching (34 to 100% reduction) and disrupts early embryonic development across all tested concentrations.
  • * Larval stages of E. connexa showed high susceptibility to acetamiprid, with larval survival dropping to 100% at low doses, and female reproduction also suffered, indicating that this insecticide could undermine integrated pest management strategies.
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The susceptibility assessment of natural enemies to pesticides is relevant before the use of selective pesticides and biological control agents within the framework of integrated pest management programs. Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) is a predator considered a potential biocontrol agent of agricultural pests in the Neothropical Region. The aim of this study was to evaluate the short and long-term effects of two broad spectrum insecticides (cypermethrin and endosulfan) and two biorational (spinosad and methoxyfenozide) registered in Argentina on young C.

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Article Synopsis
  • - Chrysoperla externa, a beneficial predator in agriculture, was tested for sensitivity to various pesticides (cypermethrin, endosulfan, methoxyfenozide, and spinosad) during its immature stages, focusing on development time, survival rates, and reproductive outcomes.
  • - While conventional insecticides (endosulfan and cypermethrin) caused high mortality rates in larval stages, biorational insecticides (spinosad and methoxyfenozide) showed less immediate and intense effects, indicating they may be safer for this beneficial predator.
  • - Overall, the study highlights that biorational insecticides support the conservation of Chrysoperla externa by minimizing negative long-term effects on its
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Background: Resistance to spinosad and methoxyfenozide has been studied in several insect pests, but there is a lack of information on Spodoptera exigua (Hübner) in Mexico. Therefore, evidence for the development of resistance in this pest to both compounds was examined. The effects of methoxyfenozide on reproductive parameters of S.

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The toxicity of two biorational insecticides, spinosad (Tracer) and methoxyfenozide (RH-2485), was tested against eggs, larvae, and pupae of the noctuid Spodoptera littoralis (Boisduval). In the first experiment, filter paper circles containing egg masses of two different age classes, young (<24 h old) and old (24-48 h old), were dipped in different concentrations of each insecticide diluted in either water or acetone. No ovicidal activity was recorded when insecticides were diluted in water.

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Article Synopsis
  • The study assessed the effects of seven modern insecticides on the lepidopteran parasitoid Hyposoter didymator, focusing on its susceptibility and various life parameters.
  • At recommended field doses, methoxyfenozide and tebufenozide were safe, while diflubenzuron showed moderate toxicity, and azadirachtin, pyriproxyfen, and spinosad were very toxic, severely affecting the parasitoid's survival and reproduction.
  • The research also evaluated the compounds' absorption and retention in H. didymator, finding that diflubenzuron had the highest absorption, indicating the need for careful evaluation of using certain insecticides in pest management programs involving this parasitoid.
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