scholarly journals Barcoding pest species in a biodiversity hot-spot: the South African polyphagous broad-nosed weevils (Coleoptera, Curculionidae, Entiminae)

2021 ◽  
Vol 9 ◽  
Author(s):  
Steffan Hansen ◽  
Pia Addison ◽  
Laure Benoit ◽  
Julien Haran
Keyword(s):  
South African ◽  
Hot Spot ◽  
Agricultural Extension ◽  
Cultivated Plants ◽  
Pest Species ◽  
Agricultural Pests ◽  
Agricultural Industry ◽  
Identification Of Species ◽  
Endemic Genera ◽  
Coi Sequences

Polyphagous broad nosed weevils (Curculionidae: Entiminae) constitute a large and taxonomically challenging subfamily that contains economically significant agricultural pests worldwide. South Africa is a hot-spot for biodiversity and several species of indigenous and endemic genera of Entiminae have shifted on to cultivated plants, with some being phytosanitary pests. The sporadic pest status of many species (where the species has an occasional economic impact on the agricultural industry, but is not encountered often enough that is is readily recognisable by researchers and agricultural extension workers) and the presence of pest complexes and cryptic species represent an identification challenge to non-specialists. Furthermore, no comprehensive identification tools exist to identify immature stages that may be found in crops/soil. In this paper, a curated barcoding database with 70 COI sequences from 41 species (39 Entiminae, 2 Cyclominae) is initiated, to assist with the complexity of identification of species in this group.

scholarly journals Barcoding pest species in a biodiversity hot-spot: the South African polyphagous broad-nosed weevils (Coleoptera, Curculionidae, Entiminae)

2021 ◽  
Author(s):  
Steffan Hansen ◽  
Pia Addison ◽  
Laure Benoit ◽  
Julien Haran
Keyword(s):  
South Africa ◽  
South African ◽  
Hot Spot ◽  
Cultivated Plants ◽  
Pest Species ◽  
Immature Stages ◽  
Agricultural Pests ◽  
Identification Of Species ◽  
Endemic Genera ◽  
Coi Sequences

Polyphagous broad nosed weevils (Curculionidae: Entiminae) constitute a large and taxonomically challenging subfamily that contains economically significant agricultural pests worldwide. South Africa is a hot-spot for biodiversity and several species of indigenous and endemic genera of Entiminae have shifted onto cultivated plants, with some being phytosanitary pests. The sporadic nature of many species, and the presence of pest complexes and cryptic species presents an identification challenge to non-specialists. Furthermore no comprehensive identification tools to identify immature stages that may be found in crops/soil exist. In this paper a curated barcoding database with 70 COI sequences from 41 species (39 Entiminae, 2 Cyclominae) is initiated, to assist with the complexity of identification of species in this group.

scholarly journals Disruption of Host-Symbiont Associations for the Symbiotic Control and Management of Pentatomid Agricultural Pests—A Review

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Gonella ◽  
Bianca Orrù ◽  
Ramona Marasco ◽  
Daniele Daffonchio ◽  
Alberto Alma
Keyword(s):  
Current Knowledge ◽  
Field Trials ◽  
Control Measures ◽  
Cultivated Plants ◽  
Pest Species ◽  
Stink Bug ◽  
Agricultural Pests ◽  
Egg Masses ◽  
Symbiotic Associations ◽  
The Family

The family Pentatomidae (Hemiptera: Heteroptera) includes several invasive stink bug species capable to attack a large number of wild and cultivated plants, causing several damages to different crops. Pentatomids rely on obligate symbiotic associations with bacteria of the family Enterobacteriaceae, mainly of the genus Pantoea. A distinctive trait of these associations is the transmission route: during oviposition, females smear egg masses with symbiont-containing secretions, which are ingested by newly hatched nymphs, allowing the symbiont to pass through their digestive tract and establish in the crypts of the posterior midgut. Preventing newborns from orally acquiring symbionts seriously affects their fitness and survival. This symbiont inheritance process can be manipulated to develop innovative pest control measures by sterilization of egg masses prior to nymph hatching. This review summarizes the recent knowledge advances concerning the gut primary symbionts of pentatomids, with a specific focus on the most troubling pest species for agriculture. Current understanding of host colonization dynamics in pentatomids is presented, as well as the phenotypic effects determined in different insect species by the alteration of vertical transmission. Details on the current knowledge on the whole bacterial communities accompanying primary symbionts are analyzed. The recent research exploiting the perturbation of symbiont acquisition by pentatomid nymphs is discussed, by considering published work on laboratory and field trials with several active substances. These translational strategies are presently regarded as promising for limiting the populations of many important pentatomid pests in a sustainable way.

scholarly journals Mitogenomic analysis of diversity of key whitefly pests in Kenya and its implication to their sustainable management

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fathiya M. Khamis ◽  
Fidelis L. O. Ombura ◽  
Inusa J. Ajene ◽  
Komivi S. Akutse ◽  
Sevgan Subramanian ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Management Strategies ◽  
Spatial Models ◽  
Abundant Species ◽  
Plant Viruses ◽  
Pest Species ◽  
Agricultural Pests ◽  
Protein Coding ◽  
Aleyrodes Proletella ◽  
Aleurodicus Dispersus

AbstractWhiteflies (Hemiptera: Aleyrodidae) are devastating agricultural pests of economic importance vectoring pathogenic plant viruses. Knowledge on their diversity and distribution in Kenya is scanty, limiting development of effective sustainable management strategies. The present study is aimed at identifying whitefly pest species present in Kenya across different agroecological zones and establish predictive models for the most abundant species in Africa. Whiteflies were sampled in Kenya from key crops known to be severely infested and identified using 16S rRNA markers and complete mitochondrial genomes. Four whitefly species were identified: Aleyrodes proletella, Aleurodicus dispersus, Bemisia afer and Trialeurodesvaporariorum, the latter being the most dominant species across all the agroecology. The assembly of complete mitogenomes and comparative analysis of all 13 protein coding genes confirmed the identities of the four species. Furthermore, prediction spatial models indicated high climatic suitability of T. vaporariorum in Africa, Europe, Central America, parts of Southern America, parts of Australia, New Zealand and Asia. Consequently, our findings provide information to guide biosecurity agencies on protocols to be adopted for precise identification of pest whitefly species in Kenya to serve as an early warning tool against T. vaporariorum invasion into unaffected areas and guide appropriate decision-making on their management.

scholarly journals Capturing the transcription factor interactome in response to sub-lethal insecticide exposure

2020 ◽  
Author(s):  
Victoria A Ingham ◽  
Sara Elg ◽  
Sanjay C Nagi ◽  
Frank Dondelinger
Keyword(s):  
Transcription Factors ◽  
Time Course ◽  
Lethal Dose ◽  
Resistance Mechanisms ◽  
Dynamic Bayesian Networks ◽  
Disease Vectors ◽  
Anopheles Coluzzii ◽  
Pest Species ◽  
Agricultural Pests ◽  
Insecticide Exposure

AbstractThe increasing levels of pesticide resistance in agricultural pests and disease vectors represents a threat to both food security and global health. As insecticide resistance intensity strengthens and spreads, the likelihood of a pest encountering a sub-lethal dose of pesticide dramatically increases. Here, we apply dynamic Bayesian networks to a transcriptome time-course generated using sub-lethal pyrethroid exposure on a highly resistant Anopheles coluzzii population. The model accounts for circadian rhythm and ageing effects allowing high confidence identification of transcription factors with key roles in pesticide response. The associations generated by this model show high concordance with lab-based validation and identifies 44 transcription factors regulating insecticide-responsive transcripts. We identify six key regulators, with each displaying differing enrichment terms, demonstrating the complexity of pesticide response. The considerable overlap of resistance mechanisms in agricultural pests and disease vectors strongly suggests that these findings are relevant in a wide variety of pest species.

Cyclacanthia n.g. (Demospongiae: Poecilosclerida: Latrunculiidae incertea sedis), a new genus of marine sponges from South African waters, and description of two new species

Zootaxa ◽  
2004 ◽  
Vol 725 (1) ◽  
pp. 1 ◽  
Author(s):  
TOUFIEK SAMAAI ◽  
VASHA GOVENDER ◽  
MICHELLE KELLY
Keyword(s):  
South African ◽  
Type Species ◽  
New Genus ◽  
East Coast ◽  
Hot Spot ◽  
Marine Sponges ◽  
The Family ◽  
Two New Species ◽  
Shallow Subtidal ◽  
Warm Temperate

The new genus Cyclacanthia n.g. is erected in the poecilosclerid Family Latrunculiidae for the type species Latrunculia bellae Samaai & Kelly, 2003, and two further species, Cyclacanthia cloverlyae sp. nov., and Cyclacanthia mzimayiensis sp. nov.. The latter species are from the subtropical east coast of South Africa, whereas C. bellae has only been found further south in warm temperate Algoa Bay. Cyclacanthia n.g. differs from other Latrunculiidae genera in the ontogeny, morphology and structure of the mature microsclere, the isospinodiscorhabd, which has only three major whorls of projections as opposed to the four in species of Latrunculia du Bocage. Additional diagnostic characters include the presence of broad swathes of megascleres that diverge from the base of the sponge towards the upper choanosome, where they form loose brushes and the typical whispy reticulation of most Latrunculiidae. The ectosome is composed of a dense tangential layer of megascleres, an irregular palisade of microscleres at the surface, and a permanently encrusting habit. Cyclacanthia n.g. is the second new latrunculid genus recently described from shallow subtidal South African waters, following major revision of the family. The presence of species in four of the five known genera in the family, on South African coastlines, suggests a diversity hot-spot for the family in this region.

Supplementary descriptions and DNA barcodes of two rarely encountered Trisetacus species (Eriophyoidea, Phytoptidae) associated with Tertiary relict conifers from the Mediterranean region

2019 ◽  
Vol 24 (9) ◽  
pp. 1631-1652
Author(s):  
Philipp Chetverikov ◽  
S.J. Bolton ◽  
M.S. Burlakovskiy ◽  
C. Craemer ◽  
P.G. Efimov ◽  
...  
Keyword(s):  
South African ◽  
Short Form ◽  
Synonymous Substitution ◽  
Complex Life Cycle ◽  
The Black Sea ◽  
Cedrus Deodara ◽  
Abies Nordmanniana ◽  
Different Populations ◽  
Coi Sequences ◽  
First Time

New records and supplementary morphological descriptions of two rarely encountered Trisetacus species from Pinaceae, T. abietis Postner 1968 and T. cedri (Nalepa 1920), are reported. Trisetacus abietis was found in Abkhazia under the needle epidermis of Abies nordmanniana (Steven) Spach, a conifer endemic to the mountainous Asian coast of the Black Sea. Trisetacus cedri was found in buds of introduced Cedrus deodara (Roxb. ex D. Don) G. Don in Abkhazia and South Africa. It is the only member of Trisetacus known from Cedrus spp. For the first time we provide sequences of two genes (COI and D1–D2 28S) of T. abietis (MN022221, MN025333) and T. cedri (MN022222, MN022223, MN025334, MN025335), along with microphotographs of the damage caused by these mites on their coniferous hosts. Sequences of D1–D2 28S of T. cedri from Abkhazian and South African populations are identical; COI sequences from different populations differ by only one synonymous substitution in a codon for asparagine. Females of T. abietis have long asymmetrical 8/7-rayed empodia, whereas males have shorter symmetrical 6/6-rayed empodia and shorter solenidia ω I. Similar sexual dimorphism in tarsal appendages was previously reported in Novophytoptus, representing an endoparasitic lineage of phytoptids on monocots. In T. cedri, a “long form” and a “short form” of both males and females were detected, suggesting a complex life cycle in this species. The evolution of Trisetacus is discussed within the broader context of the molecular phylogenies of Pinaceae and Eriophyoidea, including estimations of divergence times.

scholarly journals Review of blackfly (Diptera : Simuliidae) control in South Africa

2003 ◽  
Vol 70 (4) ◽  
Author(s):  
E. Myburgh ◽  
E.M. Nevill
Keyword(s):  
South Africa ◽  
South African ◽  
Water Flow ◽  
Pest Species ◽  
Clear Link ◽  
Control Programmes ◽  
Natural Predator ◽  
Flow Manipulation ◽  
Bacterium Bacillus ◽  
The 1960S

The medical, veterinary and economic importance of blackflies in South Africa, and the historical development of blackfly control programmes in various South African rivers, are reviewed in this paper. In 1996 it was estimated that blackflies can cause more than R 88 million damages per annum along the middle and lower Orange River where Simulium chutteri is considered the main pest species. A clear link between the construction of dams and the spread of the blackfly problem was shown. Four phases characterize the development of blackfly control in South Africa: (1) during the 1960s blackflies in the Vaal River were controlled with DDT; (2), during the 1970s and into the 1980s blackflies were controlled using water-flow manipulation; (3) when used at strategic times, water-flow manipulation could be used to enhance the effect of natural predator populations; and (4) during the 1990s the organophosphate temephos and toxins produced by the bacterium Bacillus thuringiensis var. israelensis were tested for their efficacy against blackflies. The larvicides temephos and B. thuringiensis proved to be effective and are still used in several control programmes. The latest research focuses on the factors that influence adult blackfly survival and annoyance, as well as the development of methods that can be used to protect sheep from blackfly attacks.

Selfish DNA as a method of pest control

1994 ◽  
Vol 344 (1309) ◽  
pp. 313-324 ◽  
Keyword(s):  
Genetic Load ◽  
Single Copy ◽  
Mendelian Inheritance ◽  
Host Population ◽  
Molecular Techniques ◽  
Uniparental Inheritance ◽  
Pest Species ◽  
Agricultural Pests ◽  
Selfish Dna ◽  
Host Fitness

The inheritance of most genes is tightly controlled, governed by the rules of mendelian inheritance if nuclear or uniparental inheritance if cytoplasmic. A few notable genes and cytoplasmic genomes have escaped this regulation. Such genes may spread by increasing their own rate of transmission despite reducing host fitness and may be regarded as ‘selfish’. Their population genetics are described and it appears they may impose a significant genetic load on the host population. Modern molecular techniques may enable similar loads to be imposed on pest species either by transferring selfish genes between species, or by linking deleterious genes to a selfish locus. Alternatively, ‘modifier’ genes that eliminate the virulent, or disease vectorial capacity, of the pest population may be introduced by linkage to a selfish locus. Selfish elements present in multiple copies may be preferable to single-copy elements as the former are capable of a larger reduction in host fitness. The practical application of these agents depends on five factors: (i) the rate of ‘reversion’ to a non-selfish form; (ii) the evolution of host repressor systems; (iii) their effect on host fitness, which determines their rate of invasion; (iv) the mechanism regulating host population size in the field; and (v) their ease of manipulation in the laboratory. The first two factors are the most uncertain in most systems, but should be amenable to experimental analysis. It is proposed that the development of such techniques may result in powerful new methods of population control which may be applied to both agricultural pests and disease vectors.

scholarly journals Some injurious South African Weevils

1920 ◽  
Vol 10 (3) ◽  
pp. 273-276
Author(s):  
Guy A. K. Marshall
Keyword(s):  
South African ◽  
Cultivated Plants ◽  
Undescribed Species

The following undescribed species of Curculionidae were all forwarded to the Imperial Bureau of Entomology from the Division of Entomology, Pretoria, with the information that they were attacking various cultivated plants.

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