scholarly journals Meta-analysis reveals that seed-applied neonicotinoids and pyrethroids have similar negative effects on abundance of arthropod natural enemies

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2776 ◽  
Author(s):  
Margaret R. Douglas ◽  
John F. Tooker
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Control Function ◽  
Meta Analysis ◽  
Field Studies ◽  
Target Species ◽  
Crop Species ◽  
Pyrethroid Insecticides ◽  
Toxin Exposure

BackgroundSeed-applied neonicotinoids are widely used in agriculture, yet their effects on non-target species remain incompletely understood. One important group of non-target species is arthropod natural enemies (predators and parasitoids), which contribute considerably to suppression of crop pests. We hypothesized that seed-applied neonicotinoids reduce natural-enemy abundance, but not as strongly as alternative insecticide options such as soil- and foliar-applied pyrethroids. Furthermore we hypothesized that seed-applied neonicotinoids affect natural enemies through a combination of toxin exposure and prey scarcity.MethodsTo test our hypotheses, we compiled datasets comprising observations from randomized field studies in North America and Europe that compared natural-enemy abundance in plots that were planted with seed-applied neonicotinoids to control plots that were either (1) managed without insecticides (20 studies, 56 site-years, 607 observations) or (2) managed with pyrethroid insecticides (eight studies, 15 site-years, 384 observations). Using the effect size Hedge’sdas the response variable, we used meta-regression to estimate the overall effect of seed-applied neonicotinoids on natural-enemy abundance and to test the influence of potential moderating factors.ResultsSeed-applied neonicotinoids reduced the abundance of arthropod natural enemies compared to untreated controls (d= −0.30 ± 0.10 [95% confidence interval]), and as predicted under toxin exposure this effect was stronger for insect than for non-insect taxa (QM= 8.70, df = 1,P= 0.003). Moreover, seed-applied neonicotinoids affected the abundance of arthropod natural enemies similarly to soil- or foliar-applied pyrethroids (d= 0.16 ± 0.42 or −0.02 ± 0.12; with or without one outlying study). Effect sizes were surprisingly consistent across both datasets (I2 = 2.7% for no-insecticide controls;I2 = 0% for pyrethroid controls), suggesting little moderating influence of crop species, neonicotinoid active ingredients, or methodological choices.DiscussionOur meta-analysis of nearly 1,000 observations from North American and European field studies revealed that seed-applied neonicotinoids reduced the abundance of arthropod natural enemies similarly to broadcast applications of pyrethroid insecticides. These findings suggest that substituting pyrethroids for seed-applied neonicotinoids, or vice versa, will have little net affect on natural enemy abundance. Consistent with previous lab work, our results also suggest that seed-applied neonicotinoids are less toxic to spiders and mites, which can contribute substantially to biological control in many agricultural systems. Finally, our ability to interpret the negative effect of neonicotinoids on natural enemies is constrained by difficulty relating natural-enemy abundance to biological control function; this is an important area for future study.

scholarly journals Methyl Salicylate Fails to Enhance Arthropod Predator Abundance or Predator to Pest Ratios in Cotton

2021 ◽  
Author(s):  
Steven E Naranjo ◽  
James R Hagler ◽  
John A Byers
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Methyl Salicylate ◽  
Production Systems ◽  
Control Function ◽  
Conservation Biological Control ◽  
Cotton Production ◽  
Control Activity ◽  
Synthetic Chemicals

Abstract Conservation biological control is a fundamental tactic in integrated pest management (IPM). Greater biological control services can be achieved by enhancing agroecosystems to be more favorable to the presence, survival, and growth of natural enemy populations. One approach that has been tested in numerous agricultural systems is the deployment of synthetic chemicals that mimic those produced by the plant when under attack by pests. These signals may attract arthropod natural enemies to crop habitats and thus potentially improve biological control activity locally. A 2-yr field study was conducted in the cotton agroecosystem to evaluate the potential of synthetic methyl salicylate (MeSA) to attract native arthropod natural enemies and to enhance biological control services on two key pests. Slow-release packets of MeSA were deployed in replicated cotton plots season long. The abundance of multiple taxa of natural enemies and two major pests were monitored weekly by several sampling methods. The deployment of MeSA failed to increase natural enemy abundance and pest densities did not decline. Predator to prey ratios, used as a proxy to estimate biological control function, also largely failed to increase with MeSA deployment. One exception was a season-long increase in the ratio of Orius tristicolor (White) (Hemiptera: Anthocoridae) to Bemisia argentifolii Bellows and Perring (= Bemisia tabaci MEAM1) (Hemiptera: Aleyrodidae) adults within the context of biological control informed action thresholds. Overall results suggest that MeSA would not likely enhance conservation biological control by the natural enemy community typical of U.S. western cotton production systems.

An Investigation of the Possibilities of Biological Control ofMelittomma insulareFairm. (Coleoptera, Lymexylonidae), a serious Pest of Coconut in the Seychelles

1956 ◽  
Vol 47 (4) ◽  
pp. 685-702 ◽  
Author(s):  
F. J. Simmonds
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy

The biology and general ecology ofMelittomma insulareFairm. in the Seychelles is briefly described and the difficulties in the biological control of this pest are stressed.As much information as possible was obtained concerning the species of the little-known family Lymexylonidae, particularly with regard to their biology, which in most cases has not been investigated. Several species might warrant further investigation with a view to providing natural enemies for use againstM. insulare, but in general what is known of their biology does not afford much hope that an effective parasite or predator will be found.The biology ofAtractocerus brasiliensisLep. & Serv. was investigated in detail in Trinidad but no natural enemy was found.The only possibility is thatRhizophagus dispar(Payk.), recorded as attackingHylecoetus dermestoides(L.) in England, might also attack the eggs ofM. insulare.

Silicon enhances natural enemy attraction and biological control through induced plant defences

2009 ◽  
Vol 100 (3) ◽  
pp. 367-371 ◽  
Author(s):  
O.L. Kvedaras ◽  
M. An ◽  
Y.S. Choi ◽  
G.M. Gurr
Keyword(s):  
Biological Control ◽  
Field Experiment ◽  
Recent Work ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Untreated Control ◽  
Plant Defence ◽  
Plant Defences ◽  
Pest Infestation ◽  
Arthropod Pests

AbstractSilicon (Si) is known to have a role in constitutive plant defence against arthropod pests, and recent work has illustrated involvement in induced plant defences. The present tri-trophic study tested the hypothesis that Si increases natural enemy attraction to pest-infested plants and improves biological control. Cucumber plants treated with potassium silicate (Si+) and untreated control plants (Si−) were maintained in separately vented glasshouse compartments. Y-tube olfactometer studies showed that adult Dicranolaius bellulus were significantly more attracted to Si+ plants upon which Helicoverpa armigera larvae had fed compared with Si−, pest-infested plants. Predators were not significantly more attracted to Si+ plants when comparing uninfested cucumbers. In a field experiment, we placed H. armigera-infested and uninfested Si+ and Si− cucumber plants in a lucerne stand. Removal rates of H. armigera egg baits showed predation was greater for Si+ infested plants than for other treatments. Results suggest that Si applied to plants with a subsequent pest infestation increases the plants' attractiveness to natural enemies; an effect that was reflected in elevated biological control in the field.

Supplemental food affects thrips predation and movement of Orius laevigatus (Hemiptera: Anthocoridae) and Neoseiulus cucumeris (Acari: Phytoseiidae)

2007 ◽  
Vol 97 (3) ◽  
pp. 309-315 ◽  
Author(s):  
D.J. Skirvin ◽  
L. Kravar-Garde ◽  
K. Reynolds ◽  
J. Jones ◽  
A. Mead ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Trichoderma Viride ◽  
Food Sources ◽  
Neoseiulus Cucumeris ◽  
Orius Laevigatus ◽  
Supplemental Food ◽  
Species Movement ◽  
Predation Rates

AbstractTwo experiments were done to examine the predation of thrips, and the movement of Orius laevigatus Fieber and Neoseiulus cucumeris (Oudemans) in the presence and absence of two supplemental food sources, pollen and the fungus Trichoderma viride. The presence of pollen led to a 55% reduction in predation of the thrips by N. cucumeris and a 40% reduction in thrips predation by O. laevigatus, in experiments using single predators. The presence of fungus had no significant effect on thrips predation by either of the natural enemy species. Movement of the natural enemies was examined in a multiple predator experiment, and this showed that O. laevigatus was more likely to remain on the plant in the presence of thrips and when supplemental food, either pollen or fungus, was present. For N. cucumeris, there was no association between the presence of thrips and the mite, with the majority of the mites being found on the leaves where pollen was present. Although the single and multiple predator experiments were done at different times, the indications are that the predation rates of the N. cucumeris do not differ greatly between the two experiments, suggesting that there may be a potential interference effect between the mites, which is not present for O. laevigatus. The significance of these results for the use of supplemental food sources in biological control is discussed.

scholarly journals Landscape composition mediates suppression of major pests by natural enemies in conventional cruciferous vegetables

2021 ◽  
Author(s):  
Jie Zhang ◽  
Shijun You ◽  
Dongsheng Niu ◽  
Karla Giovana Gavilanez Guaman ◽  
Ao Wang ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Positive Impact ◽  
Spatial Scales ◽  
Habitat Diversity ◽  
Landscape Composition ◽  
Dispersal Ability ◽  
Cruciferous Vegetables ◽  
Natural Habitats

ABSTRACTBackgroundConservation biological control provides an environment-friendly approach to improve the efficacy of natural enemies. Although numerous studies have demonstrated the potential of semi-natural habitats in promoting biological control in organic or unsprayed agroecosystems, few studies were conducted in conventional agricultural fields. In this study, we investigated the effects of landscape composition on the major pests of cruciferous vegetables and on the assemblages of their natural enemies in southeastern China.ResultsHabitat diversity, particularly increasing grassland proportion in the landscape, had a positive impact in controlling both small-sized pests (aphids, leaf miners, thrips and flea beetles) and Plutella xylostella. This increasing proportion also promoted greater abundance and diversity of canopy-dwelling predators, more forests supported a higher diversity of airborne enemies (parasitoids and canopy-dwelling predators) as well as a higher abundance of ground-dwelling predators. A general increase in habitat diversity was beneficial to parasitoids and ground-dwelling predators. Additionally, the proportion of forest, grassland, and non-cruciferous vegetable area, as well as habitat diversity, affected the compositions of natural enemy communities. Moreover, inconsistent effects of non-cruciferous and grassland habitats were found between sampling regions for small-sized pests and canopy-dwelling predators. Moreover, the scale at which pests and natural enemies’ abundance and richness responded most to landscape composition varied with their feeding range and dispersal ability.ConclusionOur study provides evidence that increasing the amount of semi-natural habitats and habitat diversity can result in lower pest and higher natural enemy abundance in conventional cruciferous agroecosystems. Regional conditions and spatial scales also should be considered in designing the agricultural landscape mosaic.

scholarly journals Balancing Disturbance and Conservation in Agroecosystems to Improve Biological Control

2020 ◽  
Vol 65 (1) ◽  
pp. 81-100 ◽  
Author(s):  
John F. Tooker ◽  
Matthew E. O'Neal ◽  
Cesar Rodriguez-Saona
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Crop Production ◽  
Agricultural Intensification ◽  
Conservation Practices ◽  
Insect Outbreaks ◽  
Top Down ◽  
Crop Fields ◽  
Pest Outbreaks

Disturbances associated with agricultural intensification reduce our ability to achieve sustainable crop production. These disturbances stem from crop-management tactics and can leave crop fields more vulnerable to insect outbreaks, in part because natural-enemy communities often tend to be more susceptible to disturbance than herbivorous pests. Recent research has explored practices that conserve natural-enemy communities and reduce pest outbreaks, revealing that different components of agroecosystems can influence natural-enemy populations. In this review, we consider a range of disturbances that influence pest control provided by natural enemies and how conservation practices can mitigate or counteract disturbance. We use four case studies to illustrate how conservation and disturbance mitigation increase the potential for biological control and provide co-benefits for the broader agroecosystem. To facilitate the adoption of conservation practices that improve top-down control across significant areas of the landscape, these practices will need to provide multifunctional benefits, but should be implemented with natural enemies explicitly in mind.

Some Concepts on the Ecological Basis of Biological Control of Weeds

1962 ◽  
Vol 94 (5) ◽  
pp. 507-514 ◽  
Author(s):  
C. B. Huffaker
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Insect Pests ◽  
Natural Scene ◽  
Biological Control Of Weeds ◽  
Ecological Relationships ◽  
Ecological Basis

Contrary to a common conception, employment of biological control of weeds is fundamentally the same as the employment of biological control of insect pests. The goal in each case is not eradication but the reduction of pest populations to non-injurious levels. The ecological relationships which apply in the regulation of any organism by natural enemies in the undisturbed natural scene also apply when we attempt to introduce a natural enemy not already present. While it is true that our work has an economic or applied objective, the pursuit of objectives in biological control in general takes us deeply into fundamental considerations – fundamentals which constitute the broad science of ecology.

scholarly journals Effects of predator specialization, host plant and climate on biological control of aphids by natural enemies: a meta-analysis

2013 ◽  
Vol 50 (1) ◽  
pp. 262-270 ◽  
Author(s):  
Eva Diehl ◽  
Elvira Sereda ◽  
Volkmar Wolters ◽  
Klaus Birkhofer
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Natural Enemies ◽  
Meta Analysis

scholarly journals Toxicity of Insecticides and Miticides to Natural Enemies in Australian Grains: A Review

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 187
Author(s):  
Kathy Overton ◽  
Ary A. Hoffmann ◽  
Olivia L. Reynolds ◽  
Paul A. Umina
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Current Knowledge ◽  
Farming Systems ◽  
International Organization ◽  
Carabid Beetles ◽  
Generalist Predators ◽  
Seed Treatments ◽  
Target Effects

Continued prophylactic chemical control to reduce pest populations in Australian grain farming systems has limited the effectiveness of biological control via natural enemies in crops within an integrated pest management (IPM) framework. While a variety of data is available to infer potential non-target effects of chemicals on arthropod natural enemies, much of it may be irrelevant or difficult to access. Here, we synthesise the literature relevant to Australian grain crops and highlight current knowledge gaps for potential future investment. A range of testing methodologies have been utilised, often deviating from standardised International Organization for Biological Control (IOBC) protocols. Consistent with findings from over 30 years ago, research has continued to occur predominantly at laboratory scales and on natural enemy families that are easily reared or commercially available. There is a paucity of data for many generalist predators, in particular for spiders, hoverflies, and rove and carabid beetles. Furthermore, very few studies have tested the effects of seed treatments on natural enemies, presenting a significant gap given the widespread global use of neonicotinoid seed treatments. There is a need to validate results obtained under laboratory conditions at industry-relevant scales and also prioritise testing on several key natural enemy species we have identified, which should assist with the adoption of IPM practices and decrease the reliance on broad-spectrum chemicals.

scholarly journals Enemies mediate distance- and density-dependent mortality of tree seeds and seedlings: a meta-analysis of fungicide, insecticide and exclosure studies

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202352
Author(s):  
Xiaoyang Song ◽  
Richard T. Corlett
Keyword(s):  
Density Dependence ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Plant Pathogens ◽  
Meta Analysis ◽  
Seedling Stage ◽  
Forest Community ◽  
Density Dependent ◽  
Density Dependent Mortality ◽  
Dependent Mortality

Conspecific negative distance- and density-dependence is often assumed to be one of the most important mechanisms controlling forest community assembly and species diversity globally. Plant pathogens, and insect and mammalian herbivores, are the most common natural enemy types that have been implicated in this phenomenon, but their general effects at different plant life stages are still unclear. Here, we conduct a meta-analysis of studies that involved robust manipulative experiments, using fungicides, insecticides and exclosures, to assess the contributions of different natural enemy types to distance- and density-dependent effects at seed and seedling stages. We found that distance- and density-dependent mortality caused by natural enemies was most likely at the seedling stage and was greater at higher mean annual temperatures. Conspecific negative distance- and density-dependence at the seedling stage is significantly weakened when fungicides were applied. By contrast, negative conspecific distance- and density-dependence is not a general pattern at the seed stage. High seed mass reduced distance- and density-dependent mortality at the seed stage. Seed studies excluding only large mammals found significant negative conspecific distance-dependent mortality, but exclusion of all mammals resulted in a non-significant effect of conspecifics. Our study suggests that plant pathogens are a major cause of distance- and density-dependent mortality at the seedling stage, while the impacts of herbivores on seedlings have been understudied. At the seed stage, large and small mammals, respectively, weaken and enhance negative conspecific distance-dependent mortality. Future research should identify specific agents of mortality, investigate the interactions among different enemy types and assess how global change may affect natural enemies and thus influence the strength of conspecific distance- and density-dependence.

Sign in / Sign up

Export Citation Format

Share Document