scholarly journals Compatibility and Efficacy of the Parasitoid Eretmocerus hayati and the Entomopathogenic Fungus Cordyceps javanica for Biological Control of Whitefly Bemisia tabaci

Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 425 ◽  
Author(s):  
Da Ou ◽  
Li-Mei Ren ◽  
Yuan Liu ◽  
Shaukat Ali ◽  
Xing-Min Wang ◽  
...  
Keyword(s):  
Biological Control ◽  
Bemisia Tabaci ◽  
Entomopathogenic Fungus ◽  
High Efficiency ◽  
Field Studies ◽  
Parasitism Rate ◽  
Combined Application ◽  
Development Of Resistance ◽  
Combined Use ◽  
First Time

Biological control is an effective method for whitefly management compared to the potential problems caused by chemical control, including environmental pollution and the development of resistance. Combined use of insect parasitoids and entomopathogenic fungi has shown high efficiency in Bemisia tabaci control. Here, we assessed the impacts of an entomopathogenic fungus, Cordyceps javanica, on the parasitism rate of a dominant whitefly parasitoid, Eretmocerus hayati, and for the first time also compared their separate and combined potential in the suppression of B. tabaci under semi-field conditions. Six conidial concentrations of C. javanica (1 × 103, 1 × 104, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 conidia/mL) were used to assess its pathogenicity to the pupae and adults of E. hayati. Results showed that the mortality of E. hayati increased with higher concentrations of C. javanica, but these higher concentrations of fungus had low pathogenicity to both the E. hayati pupae (2.00–28.00% mortality) and adults (2.67–34.00% mortality) relative to their pathogenicity to B. tabaci nymphs (33.33–92.68%). Bioassay results indicated that C. javanica was harmless (LC50 = 3.91 × 1010) and slightly harmful (LC50 = 5.56 × 109) to the pupae and adults of E. hayati respectively on the basis of IOBC criteria, and that E. hayati could parasitize all nymphal instars of B. tabaci that were pretreated with C. javanica, with its rate of parasitism being highest on second-instar nymphs (62.03%). Interestingly, the parasitoids from second and third-instar B. tabaci nymphs infected with C. javanica had progeny with increased longevity and developmental periods. Moreover, experimental data from 15 day semi-field studies indicate that combined application of C. javanica and E. hayati suppresses B. tabaci with higher efficiency than individual applications of both agents. Therefore, combined applications of C. javanica (1 × 108 conidia/mL) and E. hayati is a more effective and compatible biological control strategy for management of B. tabaci than using either of them individually.

scholarly journals Phototoxicity of Ultraviolet-A against the Whitefly Bemisia tabaci and Its Compatibility with an Entomopathogenic Fungus and Whitefly Parasitoid

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Muhammad Musa Khan ◽  
Ze-Yun Fan ◽  
Dylan O’Neill Rothenberg ◽  
Jing Peng ◽  
Muhammad Hafeez ◽  
...  
Keyword(s):  
Biological Control ◽  
Bemisia Tabaci ◽  
Exposure Time ◽  
Entomopathogenic Fungus ◽  
Light Exposure ◽  
Adult Emergence ◽  
Biological Control Agents ◽  
Encarsia Formosa ◽  
Parasitism Rate ◽  
Invertebrate Pests

Ultraviolet (UV) radiation significantly affects insect life and, as a result, has been widely used to control different invertebrate pests. The current results demonstrate that when Bemisia tabaci first instar nymphs are exposed to UV-A light for 12, 24, 48, and 72 h, their developmental and biological parameters are negatively affected by UV-A exposure; the effect increased with an increase in exposure time. We hypothesized that UV-A light is compatible with other biological control agents. Results showed that when the entomopathogenic fungus Cordyceps fumosorosea was applied to third instar nymphs of B. tabaci previously exposed to UV-A light, the LC50 was 3.4% lower after 72 h of exposure to UV-A light compared to the control. However, when the fungus was exposed to UV-A light, its virulence decreased with an increase in UV-A exposure time. The parasitism rate of Encarsia formosa against 24 h UV-A-exposed third instar nymphs of B. tabaci increased while the adult emergence from parasitized nymphs was not affected after UV-A light exposure. Parasitism rate was significantly reduced however following E. formosa exposure to UV-A light; but again, adult emergence was not affected from parasitized nymphs. The percentage mortality of E. formosa increased with increasing exposure time to UV-A light. The enzyme activity of SOD, CAT, GST, and AChE and the energy reserve contents were negatively affected due to UV-A exposure. Collectively, this study has demonstrated that UV-A light significantly suppresses the immune system of B. tabaci and that UV-A light is compatible with other biological control agents if it is applied separately from the biological agent.

scholarly journals The Jekyll and Hyde case of Nesidiocoris tenuis (Reuter) in the management of Bemisia tabaci (Gennadius) on tomato plants under greenhouse conditions

2021 ◽  
Author(s):  
David Wari ◽  
Takeshi Saito ◽  
Motonori Takagi ◽  
Ryo Okada ◽  
Takuya Miyamoto ◽  
...  
Keyword(s):  
Biological Control ◽  
Bemisia Tabaci ◽  
Control Strategies ◽  
Field Tests ◽  
Cost Effective ◽  
Field Studies ◽  
Tomato Plants ◽  
Nesidiocoris Tenuis ◽  
Environmentally Safe

Abstract The rise of Nesidiocoris tenuis (Reuter) as a natural enemy of various greenhouse pests in protected systems is widely reported around the globe, mainly in the Mediterranean basin, Asia, and North and Central America. In-vitro studies on improving its growth and reproduction using artificial and factitious diets, and banker plants for its breeding and propagation, and the use of violet-light (LEDs) as the attraction mechanism are well established. However, field studies are lacking in integrating these biological control components to promote N. tenuis predation on greenhouse pests. First, we performed toxicity assays in-vitro and in field conditions. Results revealed that neonicotinoids and spinosyns were toxic to N. tenuis. Avermectins & milbemycins, pyridine azomethine derivatives and diamides, in contrast, were less to moderately toxic against N. tenuis but toxic to Bemisia tabaci, a known, widespread greenhouse pest. Field tests under greenhouse conditions were performed to evaluate the role of violet-LEDs in relocating N. tenuis from banker plants to tomato plants and their augmentative effect on the densities of B. tabaci. Results showed that the movement of N. tenuis from banker plants to tomato plants was accelerated when supplemented with violet-LEDs. The accelerated resettlement of N. tenuis on tomato plants aided by selective pesticides significantly reduced B. tabaci egg, nymph and adult densities, densities that were relatively the same compared to those of the greenhouse with conventional pest control strategies. Overall, comparable outcomes in managing a pest are possible when biological control agents are integrated with environmentally safe and cost-effective approaches.

scholarly journals Compatibility between Entomopathogenic Fungi and Egg Parasitoids (Trichogrammatidae): A Laboratory Study for Their Combined Use to Control Duponchelia fovealis

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 630
Author(s):  
Emily Silva Araujo ◽  
Alex S. Poltronieri ◽  
Carolina G. Poitevin ◽  
José Manuel Mirás-Avalos ◽  
Maria Aparecida Cassilha Zawadneak ◽  
...  
Keyword(s):  
Biological Control ◽  
Entomopathogenic Fungi ◽  
Control Strategies ◽  
Adult Emergence ◽  
Biological Traits ◽  
Trichogramma Pretiosum ◽  
Biological Control Agents ◽  
Parasitism Rate ◽  
Trichogramma Species ◽  
Combined Use

The European pepper moth, Duponchelia fovealis (Lepidoptera: Crambidae), is a key pest in strawberry production. Entomopathogenic fungi (EF) and parasitoids of the Trichogrammatidae family are effective biological control agents of this pest with the potential to be used jointly for improved efficacy. This study aims to evaluate the susceptibility of Trichogramma atopovirilia and Trichogramma pretiosum to two Beauveria bassiana strains (B2 and B3) and two commercial bioinsecticides (Bovemax® and Methamax®) by applying them to D. fovealis eggs in pre- and post-parasitism periods. Pre-parasitism application of B2 and B3 did not affect the percentage of D. fovealis eggs parasitized by either Trichogramma species, except in the case of T. atopovirilia when eggs were sprayed with B3 at 1.5 × 105 conidia mL−1 (16.7% less than the control). In contrast, eggs sprayed with 1.5 × 108 conidia mL−1 of the commercial bioinsecticides were not parasitized by any Trichogramma species. Overall, the EF tested reduced the parasitism rate, adult emergence, and longevity of Trichogramma adults by less than 30% in all cases. The adverse effects of the B. bassiana strains and commercial products on the biological traits of both Trichogramma species were minimal, meaning that these agents can be used jointly in D. fovealis control strategies.

Studies on the biology and taxonomy of some Chilocorus spp. (Coleoptera: Coccinellidae) preying on Aulacaspis spp. (Hemiptera: Diaspididae) in East Africa, with the description of a new species

1977 ◽  
Vol 67 (2) ◽  
pp. 259-270 ◽  
Author(s):  
D. J. Greathead ◽  
R. D. Pope
Keyword(s):  
Biological Control ◽  
Lake Victoria ◽  
Field Studies ◽  
Dry Conditions ◽  
Tropical Areas ◽  
Taxonomic Studies ◽  
First Time ◽  
Laboratory Breeding ◽  
A New Species ◽  
Aulacaspis Tegalensis

AbstractField studies of predators on Aulacaspis tegalensis (Zhnt.) and laboratory breeding experiments, supplemented by taxonomic studies, showed that Chilocorus discoideus Crotch and C. bilineata Korsch. are junior synonyms of C. schioedtei Muls. and that two other forms, originally described as ‘aberrations’, may also belong to this species. Similarly, C. erythrocephalus Muls. and C. solitus Weise are junior synonyms of C. distigma (Klug). C. rufoplagiatus sp. n., allied to C. distigma, is described from the shores of Lake Victoria, and the Oriental species C. nigritus (F.) is recorded from the African mainland for the first time. C. distigma is found in the savanna and steppe areas of Africa and C. schioedtei in the forest and adjoining zones. Comparative studies suggest that, although C. schioedtei has a higher fecundity, it is not displaced by C. distigma as, unlike the latter, it is unable to breed under hot dry conditions. Comparison of host records for these two species show that C. distigma is not restricted to feeding on Diaspididae, as is C. schioedtei, but that otherwise the range of hosts and associated plants is similar for both species. The potential of these species and C. nigritus for use in biological control is discussed and it is suggested that C. schioedtei is only suitable for trial in tropical areas without a dry season, but that C. distigma and C. nigritus may be useful under a wider range of conditions.

The Sayan borderlands: Tuva’s ethnocultural landscapes in changing natural and sociocultural environments

2020 ◽  
Vol 13 (1) ◽  
pp. 29-36
Author(s):  
D. A. Dirin ◽  
Paul Fryer
Keyword(s):  
Cultural Landscapes ◽  
Field Studies ◽  
Social Environments ◽  
Key Factors ◽  
Role Of Government ◽  
Literary Sources ◽  
Population Migrations ◽  
The Republic ◽  
Sociocultural Processes ◽  
First Time

The paper is devoted to ethno-cultural landscapes of the Republic of Tuva. Ethnocultural landscapes (ECLs) are specific socio-environmental systems that developed as a result of the interaction of ethnic groups with their natural and social environments and are in a constant process of transformation. An attempt is made to identify the mechanisms of the formation, functioning and dynamics of ethnocultural landscapes in the specific conditions of the intracontinental cross-border mountain region, as well as to establish the main factors-catalysts of their modern changes. For the first time an attempt is made to delimit and map the ethnocultural landscapes of Tuva. For this, literary sources, statistical data and thematic maps of different times are analyzed using geoinformation methods. The results of 2014-2018 field studies are also used, during which interviews with representatives of different ethno-territorial, gender, age and social groups were taken. It is revealed that the key factors of Tuva’s ethnocultural landscape genesis are the natural isolation of its territory; the features of its landscape structure; the role of government; population migrations from other regions and the cultural diffusion provoked by them. 13 ethnocultural landscapes are identified at the regional level. Their modern transformation is determined by the shift of climatic cycles, aridisation, globalisation of sociocultural processes, changes in economic specialisation and ethnopsychological stereotypes.

The influence of herbicides on the indicators of the structure of the seeds of soybean in the conditions of the central regions of the Non-black earth zone.

2020 ◽  
Author(s):  
V.K. Khramoy ◽  
◽  
Т. D. Sikharulidze
Keyword(s):  
Field Experiment ◽  
High Efficiency ◽  
Combined Use ◽  
Central Regions ◽  
Yield Structure ◽  
Number Of Seeds

In a field experiment, it was established that of the three herbicides we studied in soybean crops, Dual Gold is the most effective. Its use increases, in comparison with the control, the number of beans per plant by 2.2 times, the number of seeds by 2.4 times, and the mass of seeds by 2.9 times. The least efficient is Fabian. In terms of most indicators of the yield structure, it is reliably inferior to Dual Gold. Zenkor is slightly inferior in efficiency to Dual Gold. The differences between them are not reliable. High efficiency (at the level of Dual Gold) was shown by the combined use of Zenkor and Fabian herbicides in doses reduced by 20%.

A Fungal Cu/Zn-Containing Superoxide Dismutase Enhances the Therapeutic Efficacy of a Plant Polyphenol Extract in Experimental Influenza Virus Infection

2010 ◽  
Vol 65 (5-6) ◽  
pp. 419-428 ◽  
Author(s):  
Julia Serkedjieva ◽  
Tsvetanka Stefanova ◽  
Ekaterina Krumova
Keyword(s):  
Superoxide Dismutase ◽  
Influenza Virus ◽  
Virus Infection ◽  
Protective Effect ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Protective Role ◽  
Combined Application ◽  
Combined Use ◽  
Experimental Influenza

The combined protective effect of a polyphenol-rich extract, isolated from Geranium sanguineum L. (PC), and a novel naturally glycosylated Cu/Zn-containing superoxide dismutase, produced from the fungal strain Humicula lutea 103 (HL-SOD), in the experimental influenza A virus infection (EIVI) in mice, induced with the virus A/Aichi/2/68 (H3N2), was investigated. The combined application of HL-SOD and PC in doses, which by themselves do not defend significantly mice in EIVI, resulted in a synergistically increased protection, determined on the basis of protective indices and amelioration of lung injury. Lung weights and consolidation as well as infectious lung virus titers were all decreased significantly parallel to the reduction of the mortality rates; lung indices were raised. The excessive production of reactive oxygen species (ROS) by alveolar macrophages (aMØ) as well as the elevated levels of the lung antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), induced by EIVI, were brought to normal. For comparative reasons the combined protective effect of PC and vitamin C was investigated. The obtained results support the combined use of antioxidants for the treatment of influenza virus infection and in general indicate the beneficial protective role of combinations of viral inhibitors of natural origin with diverse modes of action.

scholarly journals Limited host range in the idiobiont parasitoid Phymasticus coffea, a prospective biological control agent of the coffee pest Hypothenemus hampei in Hawaii

2021 ◽  
Author(s):  
Fazila Yousuf ◽  
Peter A. Follett ◽  
Conrad P. D. T. Gillett ◽  
David Honsberger ◽  
Lourdes Chamorro ◽  
...  
Keyword(s):  
Biological Control ◽  
Native Species ◽  
Biological Control Agent ◽  
Classical Biological Control ◽  
Environmental Safety ◽  
Control Agent ◽  
Hypothenemus Hampei ◽  
Parasitism Rate ◽  
Limited Host Range ◽  
Parasitoid Development

AbstractPhymastichus coffea LaSalle (Hymenoptera:Eulophidae) is an adult endoparasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera:Curculionidae:Scolytinae), which has been introduced in many coffee producing countries as a biological control agent. To determine the effectiveness of P. coffea against H. hampei and environmental safety for release in Hawaii, we investigated the host selection and parasitism response of adult females to 43 different species of Coleoptera, including 23 Scolytinae (six Hypothenemus species and 17 others), and four additional Curculionidae. Non-target testing included Hawaiian endemic, exotic and beneficial coleopteran species. Using a no-choice laboratory bioassay, we demonstrated that P. coffea was only able to parasitize the target host H. hampei and four other adventive species of Hypothenemus: H. obscurus, H. seriatus, H. birmanus and H. crudiae. Hypothenemus hampei had the highest parasitism rate and shortest parasitoid development time of the five parasitized Hypothenemus spp. Parasitism and parasitoid emergence decreased with decreasing phylogenetic relatedness of the Hypothenemus spp. to H. hampei, and the most distantly related species, H. eruditus, was not parasitized. These results suggest that the risk of harmful non-target impacts is low because there are no native species of Hypothenemus in Hawaii, and P. coffea could be safely introduced for classical biological control of H. hampei in Hawaii.

High-efficiency ternary polymer solar cells with optimized morphology of active layers enabled by few-layered β-InSe nanosheets

Nanoscale ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 6871-6883
Author(s):  
Jianming Wang ◽  
Huangzhong Yu ◽  
Chunli Hou
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Polymer Solar Cells ◽  
Active Layers ◽  
Ternary Polymer ◽  
First Time

Herein, few-layered β-InSe nanosheets are introduced into the active layers of polymer solar cells as morphological modifiers for the first time. 

scholarly journals High-Efficiency Polarizer Reflectarray Antennas for Data Transmission Links from a CubeSat

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1802
Author(s):  
Eduardo Martinez-de-Rioja ◽  
Daniel Martinez-de-Rioja ◽  
Rafael López-Sáez ◽  
Ignacio Linares ◽  
Jose A. Encinar
Keyword(s):  
Circular Polarization ◽  
Data Transmission ◽  
High Efficiency ◽  
High Gain ◽  
Dual Band ◽  
Left Handed ◽  
Linearly Polarized ◽  
Flat Profile ◽  
First Time ◽  
Collimated Beam

This paper presents two designs of high-efficiency polarizer reflectarray antennas able to generate a collimated beam in dual-circular polarization using a linearly polarized feed, with application to high-gain antennas for data transmission links from a Cubesat. First, an 18 cm × 18 cm polarizer reflectarray operating in the 17.2–22.7 GHz band has been designed, fabricated, and tested. The measurements of the prototype show an aperture efficiency of 52.7% for right-handed circular polarization (RHCP) and 57.3% for left-handed circular polarization (LHCP), both values higher than those previously reported in related works. Then, a dual-band polarizer reflectarray is presented for the first time, which operates in dual-CP in the frequency bands of 20 GHz and 30 GHz. The proposed antenna technology enables a reduction of the complexity and cost of the feed chain to operate in dual-CP, as a linear-to-circular polarizer is no longer required. This property, combined with the lightweight, flat profile and low fabrication cost of printed reflectarrays, makes the proposed antennas good candidates for Cubesat applications.

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