Geographical variation, population structure and gene flow between populations of Chrysophtharta agricola (Coleoptera: Chrysomelidae), a pest of Australian eucalypt plantations

2003 ◽  
Vol 93 (2) ◽  
pp. 137-144 ◽  
Author(s):  
H.F. Nahrung ◽  
G.R. Allen
Keyword(s):  
Gene Flow ◽  
Natural Enemies ◽  
Chemical Control ◽  
Genetic Resistance ◽  
Allelic Diversity ◽  
Native Forest ◽  
Pest Species ◽  
Eucalypt Plantations ◽  
Pest Outbreaks ◽  
High Allelic Diversity

AbstractChrysophtharta agricola (Chapuis) is a pest of commercial eucalypt plantations in Tasmania and Victoria. Vagility of pest populations may result in difficulty predicting temporal and spatial pest outbreaks, and influence genetic resistance to chemical control. Gene flow in this pest species was estimated to assess predicability of attack, the potential efficacy of natural enemies, and the likelihood of resistance build-up. Ten geographic populations of C. agricola (six from Tasmania, one from the Australian Capital Territory, one from New South Wales and two from Victoria) were examined for genetic variation and gene flow using cellulose acetate allozyme electrophoresis. Six enzyme systems (PGI, PGD, PGM, IDH, HEX and MPI) were consistently polymorphic and scorable and were used to quantify estimated gene flow between populations. FST values and analysis of molecular variance indicated that gene flow was restricted between populations. Chrysophtharta agricola exhibited high levels of heterozygosity, probably because of high allelic diversity, and because all loci examined were polymorphic. The southern-most population was the most genetically different to other Tasmanian populations, and may also have been the most recently colonized. Limited gene flow implies that outbreaks of C. agricola should be spatially predictable and populations susceptible to control by natural enemies. Our results also imply that genetic resistance to chemical control may occur under frequent application of insecticide. However, testing population movement between plantations and native forest also needs to be conducted to assess gene flow between forest types.

scholarly journals Are eucalypts Brazil's friend or foe? An entomological viewpoint

1999 ◽  
Vol 28 (2) ◽  
pp. 185-200 ◽  
Author(s):  
Jonathan D. Majer ◽  
Harry F. Recher
Keyword(s):  
Conservation Status ◽  
Physical Structure ◽  
Eucalyptus Species ◽  
Native Forest ◽  
Native Forests ◽  
Eucalypt Plantations ◽  
Pest Outbreaks ◽  
Flora Of South America ◽  
Leaf Cutting ◽  
Forest Arthropods

Vast areas of Brazil are being planted to Eucalyptus in order to provide renewable sources of timber, charcoal and cellulose. Although the rapid growth and productivity of various Eucalyptus species undoubtedly relaxes the pressure on logging of native forests, there are ecological costs. Firstly, some eucalypt species are vulnerable to pest outbreaks. A large number of native Lepidoptera, Coleoptera and leaf-cutting ants (Atta spp.), some of which have become pests, have been found on eucalypts growing in Brazil. Probably, the diverse myrtaceous flora of South America supports a fauna that can adapt to the introduced Eucalyptus species. Secondly, the leaf litter produced under Eucalyptus plantations differs substantially from that of native forests both in terms of its physical structure and chemistry, posing a range of problems for the native decomposer fauna. If microarthropod diversity is reduced, nutrient cycling could be impeded under eucalypt plantations. Thirdly, native forest canopies support a massive diversity and biomass of arthropods on which many birds, reptiles and mammals depend for food. The evidence is that invertebrate biomass and diversity are greatly reduced in the canopies of exotic eucalypt plantations. This, in turn, reduces the food-base on which forest arthropods and other animals depend, and hence their conservation status. This paper reviews the evidence for adverse ecological effects in Brazilian eucalypt plantations and suggests ways in which Brazil might meet its forestry needs, while conserving forest invertebrates and the vertebrates that depend on them.

scholarly journals Anticipating the unexpected - managing pasture pest outbreaks after large-scale land conversion

2012 ◽  
pp. 153-157
Author(s):  
T.A. Jackson ◽  
R.J. Townsend ◽  
J.E. Dunbar ◽  
C.M. Ferguson ◽  
S.D.G. Marshall ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Natural Enemies ◽  
Large Scale ◽  
Land Development ◽  
Pest Species ◽  
Remediation Strategies ◽  
Pest Outbreaks ◽  
Large Scale Land ◽  
Pest Density

Pasture pests are often held in check by natural enemies but we have observed that severe pest attack over a wide area can occur after large scale land use change. Data were reviewed from current projects and databases for pest density and damage records covering the past 30 years. The focus was on areas where large scale land change has been implemented, including new irrigation schemes, pasture development from tussock or scrub, and land moulding for drainage via "flipping" or "hump and hollow". In these situations, pest outbreaks reached unprecedented levels, e.g. 2200 grass grub larvae/m2 in the Amuri irrigation scheme, 770 porina larvae/m2 on the East Otago Plateau and 3500 manuka beetle larvae/ m2 at Cape Foulwind on the West Coast. With major land use change, a new environment is created where pest species are provided abundant resources and the initial invaders multiply rapidly, free from the pressure of natural enemies. Monitoring systems, to provide early warning of pest attack, and remediation strategies can be used to overcome damage by these pests. Keywords: Land development, pest outbreaks, grass grub, manuka beetle, porina

Biological Control Strategies

2020 ◽  
pp. 399-417
Author(s):  
Patricia J. Vittum
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Control Strategies ◽  
Insect Pest ◽  
Fungal Endophytes ◽  
Microbial Pathogens ◽  
Pest Species ◽  
Invertebrate Predators ◽  
Pest Outbreaks ◽  
Living Organisms

This chapter assesses biological control strategies that can reduce turfgrass insect pest populations. Biological control refers to the suppression of pest populations through the activity of living organisms or their by-products. Although a majority of this book is devoted to understanding turfgrass pests, most organisms associated with turfgrass are not pests but instead may be considered beneficial because they reduce thatch, help recycle soil nutrients, or are natural enemies of pest species. Pest outbreaks can sometimes be traced to the absence of natural control agents in the turf environment. Vertebrate and invertebrate predators, insect parasitoids, and microbial pathogens may act as natural enemies of turfgrass pests. Although the effect of one species of natural enemy may be minor, the combined effects of predators, parasitoids, and pathogens can cause considerable reductions in pest populations. Additional agents can be considered as biological controls. These include fungal endophytes (which confer host-plant resistance to some insects), botanicals (botanically derived insecticides), and synthetic compounds that mimic the activity of insect-produced compounds, such as growth hormones and pheromones.

scholarly journals Insect fauna of pests and their natural enemies inhabiting sorghum-panicles in Egypt

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Hosam M. K. H. El-Gepaly
Keyword(s):  
Natural Enemies ◽  
Dominant Species ◽  
Insect Pest ◽  
Pest Species ◽  
Parasitoid Species ◽  
Insect Fauna ◽  
Cryptoblabes Gnidiella ◽  
Arthropod Species ◽  
Lepidopteran Pests ◽  
Major Pest

AbstractSorghum panicles offer a very rich microenvironment for many insect pest species and their natural enemies. Thirty arthropod species belonging to 28 families, pertaining to 9 orders were obtained from sorghum panicles planted in Sohag Governorate, Egypt, during the 3 successive seasons of 2016–2018. Out of these species were 14 pests, 16 predators, and 3 parasitoids. Lepidopteran and hemipteran pests were the most dominant species-infested sorghum-panicles during the mature stages of the panicles. Three microlepidopteran pests, the noctuid, Eublemma (Autoba) gayneri (Roth.); the pyralid, Cryptoblabes gnidiella Millière, and the cosmopterigid, Pyroderces simplex Walsingham, were recorded as major pest species infesting sorghum panicles in Sohag Governorate. The dipteran parasitoid species, Nemorilla floralis (Fallen) (Tachinidae) emerged from the pupae of the E. gayneri and C. gnidiella, while the hymenopteran parasitoid, Brachymeria aegyptiaca (Chalcididae) was obtained from the pupae of all the studied microlepidopteran pests. Spiders, coccinellids, and Orius spp. were the dominant predators collected form panicles. Post-harvest, larvae, and pupae of lepidopteran pests, especially P. simplex recorded (147, 96, and 79 larvae) and (47, 30, and 73 pupae)/10 panicles in 2016, 2017, and 2018 seasons, respectively.

scholarly journals Unexpectedly High Allelic Diversity at the KIT Locus Causing Dominant White Color in the Domestic Pig

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 305-311
Author(s):  
G Pielberg ◽  
C Olsson ◽  
A-C Syvänen ◽  
L Andersson
Keyword(s):  
Coat Color ◽  
Allelic Diversity ◽  
Growth Factor Receptor ◽  
Small Sample ◽  
Color Variation ◽  
Large White ◽  
High Genetic Diversity ◽  
High Allelic Diversity ◽  
Stem Cell Growth Factor ◽  
New Alleles

Abstract Mutations in KIT encoding the mast/stem cell growth factor receptor (MGF) are responsible for coat color variation in domestic pigs. The dominant white phenotype is caused by two mutations, a gene duplication and a splice mutation in one of the copies leading to skipping of exon 17. Here we applied minisequencing and pyrosequencing for quantitative analysis of the number of copies with the splice form. An unexpectedly high genetic diversity was revealed in white pigs. We found four different KIT alleles in a small sample of eight Large White females used as founder animals in a wild boar intercross. A similar number of KIT alleles was found in commercial populations of white Landrace and Large White pigs. We provide evidence for at least two new KIT alleles in pigs, both with a triplication of the gene. The results imply that KIT alleles with the duplication are genetically unstable and new alleles are most likely generated by unequal crossing over. This study provides an improved method for genotyping the complicated Dominant white/KIT locus in pigs. The results also suggest that some alleles may be associated with negative pleiotropic effects on other traits.

scholarly journals Givira ethela (Neumoegen and Dyar, 1893) (Lepidoptera: Cossidae), A Previously Unidentified Pest on Vitis vinifera (L.)

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 239
Author(s):  
Davide Scaccini ◽  
Enrico Ruzzier ◽  
Kent M. Daane
Keyword(s):  
Vitis Vinifera ◽  
Natural Enemies ◽  
Management Practices ◽  
Agricultural Sector ◽  
Central Valley ◽  
Vitis Vinifera L ◽  
Correct Identification ◽  
Pest Species ◽  
Monitoring Methods ◽  
Management Options

Grape cultivation is a billion-dollar agricultural sector in California, where invasive or novel pest species can disrupt management practices. We report herein on a new pest associated with California vineyards, the carpentermoth Givira ethela (Neumoegen and Dyar, 1893). Rather than an invasive species, G. ethela appears to be a newly recognized wood-boring pest of Vitis vinifera (L.) in regions of California’s Central Valley, where its initial occurrence has been dated back to, at least, the beginning of the 2000s. The habitus of adult, genitalia and pupa is illustrated. Givira ethela distribution in California is updated including published records and new data. Carpentermoth galleries seem to facilitate the access of Planococcus ficus Signoret, 1875 to vine sap and protection from natural enemies, environmental stresses, and pesticide treatments. Notes on pest status, life history, monitoring practices, natural enemies, and management options on grapes are also discussed. Tools for the Integrated Pest Management of G. ethela should include the correct identification of the insect and its damage, a full understanding of its biology and ecology, the application of monitoring methods, and the identification of economic thresholds and injury levels.

scholarly journals Potential natural enemies of the invasive rugose spiraling whitefly, Aleurodicus rugioperculatus Martin in India

2017 ◽  
Vol 30 (4) ◽  
pp. 236 ◽  
Author(s):  
K. Selvaraj ◽  
R. Sundararaj ◽  
T. Venkatesan ◽  
Chandish R. Ballal ◽  
S. K. Jalali ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Tamil Nadu ◽  
Ornamental Plants ◽  
Coi Gene ◽  
Molecular Diagnostic ◽  
Pest Species ◽  
Molecular Tools ◽  
Accession Number ◽  
Custard Apple ◽  
First Time

A invasive rugose spiraling whitefly (RSW) <em>Aleurodicus rugioperculatus</em> Martin (Hemiptera: Aleyrodidae) was found infesting coconut, banana, custard apple and several ornamental plants in Tamil Nadu, Andhra Pradesh and Kerala for the first time in India. The identity of the pest species was determined through morphological and molecular tools. Furthermore cytochrome c oxidase-I gene (658 bp) of RSW was sequenced (GenBank accession number KY209909) which would serve as an ideal molecular diagnostic marker for its identification irrespective of its phenotypic plasticity. During the survey, several natural enemies were recorded and maximum parasitism was recorded by <em>Encarsia guadeloupae</em> Viggiani (Hymenoptera: Aphelinidae) and its COI gene was sequenced and deposited as <em>Encarsia</em> sp. (GenBank accession number KY223606). Per cent parasitism ranged from 20.0 to 60.0 % in different collection locations, highest parasitism being recorded in Kerala as compared to other states. The predators recorded were <em>Mallada</em> sp., few coccinellids and predatory mites. This communication is the first report of the rugose spiraling whitefly, its host plant range and associated natural enemies in India.

scholarly journals Desert Tortoises in the Genomic Age: Population Genetics and the Landscape

2017 ◽  
Author(s):  
H. Bradley Shaffer ◽  
Evan McCartney-Melstad ◽  
Peter L. Ralph ◽  
Gideon Bradburd ◽  
Erik Lundgren ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Resistance ◽  
Habitat Modeling ◽  
Desert Tortoise ◽  
Conservation Genomics ◽  
California Department ◽  
Resistance Distance ◽  
Tissue Samples ◽  
Continuous Space ◽  
Landscape Genomics

The California Department of Fish and Wildlife (CDFW) provided research funds to study the conservation genomics and landscape genomics of the Mojave desert tortoise, Gopherus agassizii, in response to the Desert Renewable Energy Conservation Plan (DRECP). To do this, we consolidated tissue samples of the desert tortoise from across the species range within California and southern Nevada, generated a DNA dataset consisting of full genomes of 270 tortoises, and analyzed the way in which the environment of the desert tortoise has determined modern patterns of relatedness and genetic diversity across the landscape. Here we present the implications of these results for the conservation and landscape genomics of the desert tortoise. Our work strongly indicates that several well-defined genetic groups exist within the species, including a primary north-south genetic discontinuity at the Ivanpah Valley and another separating western from eastern Mojave samples. We also use existing desert tortoise habitat modeling data with a novel extension of genetic "resistance distance" using geographic maps of continuous space to predict the relative impacts of five proposed development alternatives within the DRECP and rank them with respect to their likely impacts on desert tortoise gene flow and connectivity in the Mojave. Finally, we analyzed the impacts of each of the 214 distinct proposed development area "chunks", derived from the proposed development polygons, and ranked each chunk in terms of its range-wide impacts on desert tortoise gene flow.

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