scholarly journals Ants defend aphids against lethal disease

2009 ◽  
Vol 6 (2) ◽  
pp. 205-208 ◽  
Author(s):  
Charlotte Nielsen ◽  
Anurag A. Agrawal ◽  
Ann E. Hajek
Keyword(s):  
Social Insects ◽  
Natural Enemies ◽  
Disease Transmission ◽  
Field Experiments ◽  
Fungal Infections ◽  
Pandora Neoaphidis ◽  
Aphid Pathogen ◽  
Formica Podzolica

Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis , protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, Pandora neoaphidis . In field experiments, bodies of fungal-killed aphids were quickly removed from ant-tended aphid colonies. Ant workers were also able to detect infective conidia on the cuticle of living aphids and responded by either removing or grooming these aphids. Our results extend the long-standing view of ants as mutualists and protectors of aphids by demonstrating focused sanitizing and quarantining behaviour that may lead to reduced disease transmission in aphid colonies.

scholarly journals Dampak Tanaman Transgenik Bt terhadap Populasi Serangga Pengendali Hayati

2016 ◽  
Vol 1 (2) ◽  
pp. 76
Author(s):  
Bahagiawati A. Husin
Keyword(s):  
Transgenic Plants ◽  
Transgenic Plant ◽  
Natural Enemies ◽  
Plant Resistance ◽  
Field Experiments ◽  
Insect Pests ◽  
Plant Resistance To Insects ◽  
Sequential Experiments ◽  
Genetic Engineering Technology ◽  
The Impact

<p class="p1">An alternative technique to improve plant resistance to insect pests is plant transformation using the genetic engineering technology. Several transgenic plants resistant to insect have been produced and commercially released to environment in some industrial and developing countries. Before release, transgenic plants need to be assessed for their potential risks to human health and environment. One of the environmental risk assessments is the potential risk to non-target insects, including the biocontrol insects. Laboratories, glasshouse, and field experiments have been conducting the study of the impact of transgenic plant resistance to insect, especially transgenic Bt plants to the population of predators and parasitoids. However the results were controversial. The objective of this review is to inform some of controversial results, and to suggest serial experiments need to be done to solve the problem. The impact of the transgenic plant resistance to insects depends on several factors, such as genes that are used to transform the plants, the kind of plant pests, and the kind and stages of the insect natural enemies. Results of the experiments were influenced by sites of the experiments (laboratory, glasshouse, or field) and contact of the natural enemies to the toxin. Some experiments showed that the transgenic Bt plants have no impact to the natural enemies population, and otherwise. Due to the controversial results, the experiment and assessment should be done in depth and carefully studied. A sequential experiments need to be adopted to avoid the misleading interpretation, and the assessment need to be based on a case by case study.</p>

scholarly journals Macroecology of parental care in arthropods: higher mortality risk leads to higher benefits of offspring protection in tropical climates

2019 ◽  
Author(s):  
Eduardo S. A. Santos ◽  
Pedro Penna Bueno ◽  
James Gilbert ◽  
Glauco Machado
Keyword(s):  
Parental Care ◽  
Mortality Risk ◽  
Natural Enemies ◽  
Field Experiments ◽  
Biotic Interactions ◽  
Tropical Species ◽  
Tropical Regions ◽  
Offspring Protection ◽  
Tropical Climates ◽  
The Tropics

The intensity of biotic interactions varies around the world, in such a way that mortality risk imposed by natural enemies is usually higher in the tropics. A major role of offspring attendance is protection against natural enemies, so the benefits of this behaviour should be higher in tropical regions. We tested this macroecological prediction with a meta‐regression of field experiments in which the mortality of guarded and unguarded broods was compared in arthropods. Mortality of unguarded broods was higher, and parental care was more beneficial, in warmer, less seasonal environments. Moreover, in these same environments, additional lines of defence further reduced offspring mortality, implying that offspring attendance alone is not enough to deter natural enemies in tropical regions. These results help to explain the high frequency of parental care among tropical species and how biotic interactions influence the occurrence of parental care over large geographic scales. Finally, our findings reveal that additional lines of defences – an oftentimes neglected component of parental care – have an important effect on the covariation between the benefits of parental care and the climate‐mediated mortality risk imposed by natural enemies.

scholarly journals Multi-Scale Airborne Infectious Disease Transmission

2020 ◽  
Author(s):  
Charles F. Dillon ◽  
Michael B. Dillon
Keyword(s):  
Disease Transmission ◽  
Fungal Pathogens ◽  
Field Experiments ◽  
Disease Outbreak ◽  
Disease Spread ◽  
Epidemic Disease ◽  
Airborne Transmission ◽  
Regulatory Standards ◽  
Airborne Disease ◽  
Methodological Guidelines

Airborne disease transmission is central to many scientific disciplines including agriculture, veterinary biosafety, medicine, and public health. Legal and regulatory standards are in place to prevent agricultural, nosocomial, and community airborne disease transmission. However, the overall importance of the airborne pathway is underappreciated, e.g.,, US National Library of Medicine’s Medical Subjects Headings (MESH) thesaurus lacks an airborne disease transmission indexing term. This has practical consequences as airborne precautions to control epidemic disease spread may not be taken when airborne transmission is important, but unrecognized. Publishing clearer practical methodological guidelines for surveillance studies and disease outbreak evaluations could help address this situation. To inform future work, this paper highlights selected, well-established airborne transmission events - largely cases replicated in multiple, independently conducted scientific studies. Methodologies include field experiments, modeling, epidemiology studies, disease outbreak investigations and mitigation studies. Collectively, this literature demonstrates that airborne viruses, bacteria, and fungal pathogens have the capability to cause disease in plants, animals, and humans over multiple distances – from near range (< 5 m) to continental (> 500 km) in scale. The plausibility and implications of undetected airborne disease transmission are discussed, including the notable underreporting of disease burden for several airborne transmitted diseases.

Enhancing floral and habitat diversity for augmenting natural enemies in rice ecosystem of Thanjavur, Tamil Nadu, India

2019 ◽  
Vol 56 (3) ◽  
pp. 285-293
Author(s):  
R Nalini ◽  
S Porpavai
Keyword(s):  
Grain Yield ◽  
Natural Enemies ◽  
Field Experiments ◽  
Insect Pest ◽  
Food Resource ◽  
Habitat Diversity ◽  
Mean Value ◽  
Rice Crop ◽  
The Mean ◽  
Rice Ecosystem

Field experiments on "Enhancing floral and habitat diversity for augmenting natural enemies in Thanjavur rice belt" was conducted during kharif (2017 and 2018) and rabi (2017). In habitat diversified rice crop, the main crop of rice was maintained along with flowering vegetation in field bunds viz., cowpea, green gram, black gram, sunflower, gingelly, bhendi, cluster bean, maize and marigold. Weeds mainly from Umbelliferae, Leguminosae and Compositae that support natural enemies were also maintained adjacent to rice bunds. Non-crop habitat included straw heaps on rice bunds. Daincha was planted in rogue spacing and bird perches installed to encourage both the natural enemies and insectivorous birds. The mean value of insect pest population was about 56 per cent lower in habitat diversified rice crop (7.39 insects /5 sweeps) than that of pure rice crop (16.87 insects /5 sweeps). In the case of mean value of natural enemy population, habitat diversified rice crop (26.74 individuals /5 sweeps) recorded two times higher population than that of pure rice crop (13.40 individuals /5 sweeps). In habitat diversified rice crop the pest-defender ratio was high in all the periods of observation compared to pure rice crop. The mean pest:defender ratio was 1: 3.74 in habitat diversified rice crop as compared to 1: 0.89 in pure rice crop. The mean grain yield recorded was 4.99 t/ha in habitat diversified rice crop as compared to 4.36 t/ha in pure rice crop. In habitat diversified rice crop, the per cent increased grain yield recorded over pure rice crop ranged from 10.43 to 21.18.Crop diversification and non-crop habitats certainly encouraged natural biological control by supplementing food resource and shelter. Over the years complex food web would persist leading to sustainable and ecofriendly insect pest management in rice ecosystem.

scholarly journals Transmission to Eels, Portals of Entry, and Putative Reservoirs of Vibrio vulnificus Serovar E (Biotype 2)

2001 ◽  
Vol 67 (10) ◽  
pp. 4717-4725 ◽  
Author(s):  
Ester Marco-Noales ◽  
Miguel Milán ◽  
Belén Fouz ◽  
Eva Sanjuán ◽  
Carmen Amaro
Keyword(s):  
Disease Transmission ◽  
Field Experiments ◽  
Vibrio Vulnificus ◽  
Skin Surface ◽  
Etiologic Agent ◽  
In Vitro Assays ◽  
First Time ◽  
Natural Outbreak ◽  
Tank Water

ABSTRACT Vibrio vulnificus serovar E (formerly biotype 2) is the etiologic agent that is responsible for the main infectious disease affecting farmed eels. Although the pathogen can theoretically use water as a vehicle for disease transmission, it has not been isolated from tank water during epizootics to date. In this work, the mode of transmission of the disease to healthy eels, the portals of entry of the pathogen into fish, and their putative reservoirs have been investigated by means of laboratory and field experiments. Results of the experiments of direct and indirect host-to-host transmission, patch contact challenges, and oral-anal intubations suggest that water is the prime vehicle for disease transmission and that gills are the main portals of entry into the eel body. The pathogen mixed with food can also come into the fish through the gastrointestinal tract and develop the disease. These conclusions were supported by field data obtained during a natural outbreak in which we were able to isolate this microorganism from tank water for the first time. The examination of some survivors from experimental infections by indirect immunofluorescence and scanning electron microscopy showed thatV. vulnificus serovar E formed a biofilm-like structure on the eel skin surface. In vitro assays demonstrated that the ability of the pathogen to colonize both hydrophilic and hydrophobic surfaces was inhibited by glucose. The capacity to form biofilms on eel surface could constitute a strategy for surviving between epizootics or outbreaks, and coated survivors could act as reservoirs for the disease.

scholarly journals Potential of Quercetin to Reduce Herbivory without Disrupting Natural Enemies and Pollinators

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 476
Author(s):  
Eric W. Riddick
Keyword(s):  
Life History ◽  
Secondary Metabolite ◽  
Natural Enemies ◽  
Field Experiments ◽  
Insect Herbivory ◽  
Insect Behavior ◽  
Terrestrial Plants ◽  
Life History Parameters ◽  
Quercetin Concentration

Quercetin is one of the most abundant flavonoids in terrestrial plants and pollen. In living plants, quercetin can function as a secondary metabolite to discourage insect herbivory. Literature on insect-quercetin interactions was searched and data synthesized to test the hypothesis that quercetin can become an effective biocide to reduce herbivory without disrupting natural enemies and pollinators. The USDA, National Agricultural Library, DigiTop Navigator platform was used to search the literature for harmful versus nonharmful effects of quercetin on insect behavior, physiology, and life history parameters. Quercetin effects were evaluated on herbivores in five insect orders, natural enemies in two orders, and pollinators in one order. Quercetin was significantly more harmful to Hemiptera, Diptera, and Lepidoptera but significantly more nonharmful to Coleoptera. Harmful and nonharmful effects to Orthoptera were indistinguishable. Quercetin had significantly more harmful (than nonharmful) effects on herbivores when data from the five insect orders were combined. Quercetin concentration (mg/mL) did not significantly affect these results. Quercetin was significantly more nonharmful to natural enemies (Coleoptera and Hymenoptera, combined) and pollinators (Hymenoptera). This study suggests that quercetin could prevent herbivory without disrupting natural enemies and pollinators, but field experiments are necessary to substantiate these results.

scholarly journals Canopy-Dwelling Arthropod Response to Rynaxypyr and Lambda-Cyhalothrin Treatments in Maize

2019 ◽  
Vol 50 (4) ◽  
pp. 236-243
Author(s):  
S. Keszthelyi ◽  
Z. Pónya
Keyword(s):  
Endangered Species ◽  
Natural Enemies ◽  
Ostrinia Nubilalis ◽  
Field Experiments ◽  
The Other ◽  
Arthropod Community ◽  
Corn Production ◽  
Maize Field ◽  
Lambda Cyhalothrin ◽  
Maize Grain

Abstract The technology of grain corn production has recently been continuously changing due to spreading of insecticidal in-crop treatments in Europe. The aim of these interventions is to prevent damage caused by serious lepidopterous pests in maize. We carried out in-maize field experiments using two different active ingredients of insecticides in four consecutive years (2014–2017). A field experiment was conducted to compare the effect of applications of rynaxypyr (ANT) and rynaxypyr + lambda-cyhalothrin (PYR) on the canopy-dwelling arthropod community in commercial maize grain acreage. The effects of both ANT and PYR treatments against Ostrinia nubilalis Hübner (Lep.: Crambidae) were tested through four-year field experiments. The quantitative and qualitative assemblages of the perished arthropods and diversity alterations measured by canopy netting and grounded tarpaulins greatly differed in the different insecticide treatments. A significant number of dead arthropods was recorded after PYR treatment. Populations of other natural enemies (Coccinellidae, Chrysopidae, etc.) and endangered species (Calomobius filum, Rossi) were also negatively affected. The arthropod community of the examined maize plots was drastically altered by sprayings, which, among other factors, may account for the mass appearance of the other non-target pest organisms (Aphidae: Rhopalosiphum spp., Miridae: Trygonotylus spp.).

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