scholarly journals Conservation of Non-Pest Whiteflies and Natural Enemies of the Cabbage Whitefly Aleyrodes proletella on Perennial Plants for Use in Non-Crop Habitats

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 774
Author(s):  
Sebastian Laurenz ◽  
Rainer Meyhöfer

Aleyrodes proletella causes severe economic damage to several Brassica crops. Its naturally occurring enemies often immigrate late in the season or appear in low numbers on cabbage. This field study aims to permanently increase the local abundance of A. proletella’s natural enemies by providing the non-pest whitefly Aleyrodes lonicerae as an alternative and overwintering host/prey. Therefore, the population dynamics of natural enemies on different perennial herbaceous plants pre-infested with A. lonicerae were determined at two field locations over two winter periods. Most A. lonicerae colonized (on average 166.22 puparia per m²) and overwintered (342.19 adults per m²) on wood avens Geum urbanum. Furthermore, the abundance of A. proletella main parasitoid Encarsia tricolor (28.50 parasitized puparia per m²) and spiders (12.13 per m²) was 3–74 times and 3–14 times higher, respectively, on G. urbanum compared to the other experimental plants. Conclusively, G. urbanum pre-infested with A. lonicerae permanently promoted natural enemies of A. proletella by serving as shelter, reproduction, and overwintering habitat. A potential implementation of G. urbanum in conservation biological control strategies (e.g., tailored flower strips, hedgerows) against A. proletella are discussed and suggestions for future research are given.

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3795 ◽  
Author(s):  
Hafiz Sohaib Ahmed Saqib ◽  
Minsheng You ◽  
Geoff M. Gurr

Conservation biological control emphasizes natural and other non-crop vegetation as a source of natural enemies to focal crops. There is an unmet need for better methods to identify the types of vegetation that are optimal to support specific natural enemies that may colonize the crops. Here we explore the commonality of the spider assemblage—considering abundance and diversity (H)—in brassica crops with that of adjacent non-crop and non-brassica crop vegetation. We employ spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato harbour spider morphospecies and functional groups that are also present in brassica crops. In contrast, pumpkin and litchi contain spiders not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the utility of advanced statistical approaches for identifying spatial relationships between natural enemies and the land uses most likely to offer alternative habitats for conservation biological control efforts that generates testable hypotheses for future studies.


Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 679
Author(s):  
Marta Kovač ◽  
Michał Gorczak ◽  
Marta Wrzosek ◽  
Cezary Tkaczuk ◽  
Milan Pernek

The oak lace bug (OLB), Corythucha arcuata (Hemiptera: Tingidae), was first identified as an invasive pest in Europe in northern Italy in 2000 and since then it has spread rapidly, attacking large forested areas in European countries. The OLB is a cell sap-sucking insect that is native to North America, with Quercus spp. as its main host. Its rapid expansion, successful establishment in invaded countries, and observations of more damage to hosts compared to native areas are most likely due to a lack of natural enemies, pathogens and competitors. In its native area, various natural enemies of OLBs have been identified; however, little is known about the occurrence and impact of OLB pathogens. None of the pathogenic fungi found on OLBs in natural conditions have been identified until now. In this study, we provide evidence of four entomopathogenic fungi that are naturally occurring on invasive OLBs found in infested pedunculate oak forests in eastern Croatia. On the basis of their morphology and multilocus molecular phylogeny, the fungi were identified as Beauveria pseudobassiana, Lecanicillium pissodis, Akanthomyces attenuatus and Samsoniella alboaurantium. The sequences generated for this study are available from GenBank under the accession numbers MT004817-MT004820, MT004833-MT004835, MT027501-MT27510, and MT001936-MT0011943. These pathogenic species could facilitate biological control strategies against OLBs.


2017 ◽  
Author(s):  
Hafiz Sohaib Saqib ◽  
Minsheng You ◽  
Geoff M Gurr

Conservation biological control emphasizes the importance of vegetation other than the focal crop for providing natural enemies with refuge and shelter against disturbance. There is an unmet need for better methods to identify types of vegetation that are optimal to support specific natural enemies that may colonize into crops. Here we explore the commonality of the spider fauna of brassica crops with that of adjacent crops of other species and non-crop vegetation, employing spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato offer the best opportunity for promoting spider taxa that are also brassica-active species. In contrast, pumpkin and litchi contain species not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the potential utility of advanced statistical approaches for identifying spatial relationships of species and identify the land uses most likely to offer alternative habitats for spider conservation biological control efforts and generates testable hypotheses for future studies.


Author(s):  
Hafiz Sohaib Saqib ◽  
Minsheng You ◽  
Geoff M Gurr

Conservation biological control emphasizes the importance of vegetation other than the focal crop for providing natural enemies with refuge and shelter against disturbance. There is an unmet need for better methods to identify types of vegetation that are optimal to support specific natural enemies that may colonize into crops. Here we explore the commonality of the spider fauna of brassica crops with that of adjacent crops of other species and non-crop vegetation, employing spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato offer the best opportunity for promoting spider taxa that are also brassica-active species. In contrast, pumpkin and litchi contain species not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the potential utility of advanced statistical approaches for identifying spatial relationships of species and identify the land uses most likely to offer alternative habitats for spider conservation biological control efforts and generates testable hypotheses for future studies.


2019 ◽  
Vol 48 (4) ◽  
pp. 894-902 ◽  
Author(s):  
A E Iskra ◽  
J L Woods ◽  
D H Gent

Abstract The twospotted spider mite (Tetranychus urticae Koch) is a common pest in agricultural and ornamental crops. This pest can be controlled by resident predatory arthropods in certain situations. This research quantified the stability and resiliency of established conservation biological control of the twospotted spider mite in hop over a 5-yr period associated with nitrogen fertilization rate and use of a broad-spectrum insecticide. Biological control generally was stable and resilient over a sixfold range of nitrogen fertilization rates, and in only 1 of 5 yr did elevated nitrogen rates significantly affect populations of spider mites. In contrast, one application of the insecticide bifenthrin was associated with disruption of biological control and a severe outbreak of spider mites. The complex of natural enemies suppressed the outbreak during the same year in which bifenthrin was applied, but only after populations of spider mites exceeded levels associated with economic damage. However, in the following year the system returned to an equilibrium state where spider mites were suppressed below economically damaging levels. Therefore, conservation biological control in hop appears stable and robust to factors such as nitrogen fertilization that increase reproductive rates of spider mites but may be sensitive to factors such as nonselective insecticides that are lethal to natural enemies. Conservation biological control can be considered resilient to a single use of a nonselective insecticide in the year following the application, but not within the year of application.


Author(s):  
Sandra A. Allan

Manipulation of insect behavior can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioral repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed based on behavioral manipulation and include mass trapping, attract-and-kill, auto-dissemination, mating and host plant location disruption, and push-pull. Insight into application of these strategies for insect pests within Diptera, Lepidoptera, Coleoptera, and Hemiptera/Thysanoptera are provided, but first with an overview of economic damage and traditional control approaches, and overview of relevant behavioral/ecological traits. Then examples are provided of how these different control strategies are applied for each taxonomic group. The future of these approaches in the context of altered crop development for repellency or as anti-feedants, the effects of climate change and the risks of behaviorally-based methods are discussed.


2014 ◽  
Vol 24 (06) ◽  
pp. 1450077 ◽  
Author(s):  
Matthew A. Morena ◽  
Kevin M. Short

We report on the tendency of chaotic systems to be controlled onto their unstable periodic orbits in such a way that these orbits are stabilized. The resulting orbits are known as cupolets and collectively provide a rich source of qualitative information on the associated chaotic dynamical system. We show that pairs of interacting cupolets may be induced into a state of mutually sustained stabilization that requires no external intervention in order to be maintained and is thus considered bound or entangled. A number of properties of this sort of entanglement are discussed. For instance, should the interaction be disturbed, then the chaotic entanglement would be broken. Based on certain properties of chaotic systems and on examples which we present, there is further potential for chaotic entanglement to be naturally occurring. A discussion of this and of the implications of chaotic entanglement in future research investigations is also presented.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 226
Author(s):  
Siying Fu ◽  
Yujie Duan ◽  
Siqi Wang ◽  
Yipeng Ren ◽  
Wenjun Bu

Riptortus pedestris (Hemiptera: Alydidae) is a major agricultural pest in East Asia that causes considerable economic losses to the soybean crop each year. However, the molecular mechanisms governing the growth and development of R. pedestris have not been fully elucidated. In this study, the Illumina HiSeq6000 platform was employed to perform de novo transcriptome assembly and determine the gene expression profiles of this species across all developmental stages, including eggs, first-, second-, third-, fourth-, and fifth-instar nymphs, and adults. In this study, a total of 60,058 unigenes were assembled from numerous raw reads, exhibiting an N50 length of 2126 bp and an average length of 1199 bp, and the unigenes were annotated and classified with various databases, such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Gene Ontology (GO). Furthermore, various numbers of differentially expressed genes (DEGs) were calculated through pairwise comparisons of all life stages, and some of these DEGs were associated with immunity, metabolism, and development by GO and KEGG enrichment. In addition, 35,158 simple sequence repeats (SSRs) and 715,604 potential single nucleotide polymorphisms (SNPs) were identified from the seven transcriptome libraries of R. pedestris. Finally, we identified and summarized ten wing formation-related signaling pathways, and the molecular properties and expression levels of five wing development-related genes were analyzed using quantitative real-time PCR for all developmental stages of R. pedestris. Taken together, the results of this study may establish a foundation for future research investigating developmental processes and wing formation in hemimetabolous insects and may provide valuable data for pest control efforts attempting to reduce the economic damage caused by this pest.


2009 ◽  
Vol 36 (7) ◽  
pp. 553 ◽  
Author(s):  
Z. Austin ◽  
S. Cinderby ◽  
J. C. R. Smart ◽  
D. Raffaelli ◽  
P. C. L. White

Context. Some species that are perceived by certain stakeholders as a valuable resource can also cause ecological or economic damage, leading to contrasting management objectives and subsequent conflict between stakeholder groups. There is increasing recognition that the integration of stakeholder knowledge with formal scientific data can enhance the information available for use in management. This is especially true where scientific understanding is incomplete, as is frequently the case for wide-ranging species, which can be difficult to monitor directly at the landscape scale. Aims. The aim of the research was to incorporate stakeholder knowledge with data derived from formal quantitative models to modify predictions of wildlife distribution and abundance, using wild deer in the UK as an example. Methods. We use selected predictor variables from a deer–vehicle collision model to estimate deer densities at the 10-km square level throughout the East of England. With these predictions as a baseline, we illustrate the use of participatory GIS as a methodological framework for enabling stakeholder participation in the refinement of landscape-scale deer abundance maps. Key results. Stakeholder participation resulted in modifications to modelled abundance patterns for all wild deer species present in the East of England, although the modifications were minor and there was a high degree of consistency among stakeholders in the adjustments made. For muntjac, roe and fallow deer, the majority of stakeholder changes represented an increase in density, suggesting that populations of these species are increasing in the region. Conclusions. Our results show that participatory GIS is a useful technique for enabling stakeholders to contribute to incomplete scientific knowledge, especially where up-to-date species distribution and abundance data are needed to inform wildlife research and management. Implications. The results of the present study will serve as a valuable information base for future research on deer management in the region. The flexibility of the approach makes it applicable to a range of species at different spatial scales and other wildlife conflict issues. These may include the management of invasive species or the conservation of threatened species, where accurate spatial data and enhanced community involvement are necessary in order to facilitate effective management.


Author(s):  
Xiuling Yang ◽  
Yinzi Li ◽  
Aiming Wang

Potyviruses (viruses in the genus Potyvirus, family Potyviridae) constitute the largest group of known plant-infecting RNA viruses and include many agriculturally important viruses that cause devastating epidemics and significant yield losses in many crops worldwide. Several potyviruses are recognized as the most economically important viral pathogens. Therefore, potyviruses are more studied than other groups of plant viruses. In the past decade, a large amount of knowledge has been generated to better understand potyviruses and their infection process. In this review, we list the top 10 economically important potyviruses and present a brief profile of each. We highlight recent exciting findings on the novel genome expression strategy and the biological functions of potyviral proteins and discuss recent advances in molecular plant–potyvirus interactions, particularly regarding the coevolutionary arms race. Finally, we summarize current disease control strategies, with a focus on biotechnology-based genetic resistance, and point out future research directions. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


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