scholarly journals Aquatain® Causes Anti-Oviposition, Egg Retention, Oocyte Melanization and Triggers Female Death in Ae. Aegypti

2021 ◽  
Author(s):  
HAMADY DIENG ◽  
Storm McLean ◽  
Holly Stradling ◽  
Cole Morgan ◽  
Malik Gordon ◽  
...  
Keyword(s):  
Control Strategies ◽  
Integrated Control ◽  
Genetic Resistance ◽  
Choice Test ◽  
Surface Films ◽  
Cayman Islands ◽  
Water Control ◽  
Egg Retention ◽  
Egg Deposition ◽  
Male To Female

Abstract Background: In arboviral disease systems where the virus can be transmitted from male to female and from one generation to the next, targeting the female (especially when she is pregnant) can help alter the persistence of the virus in nature and its transmission. This is typical of Ae. aegypti, which has been unmanageable due to the development of insecticide resistance. Despite evidence that monomolecular surface films prevent the selection of genetic resistance, their potential in Aedes vector control remains largely unexplored. Methods: We examined the oviposition, egg retention, oocyte melanization, and female mortality of the Cayman Islands strain of Ae. aegypti, using choice and no-choice bioassays involving Aquatain® Mosquito Formulation (AMF). Results: When presented with similar opportunities to oviposit in two sites treated with AMF and two others with water (control), egg deposition rates were significantly higher in water than in oil presence. We also observed a matching pattern of egg deposition preference in arenas with more options in AMF-treated sites. Females laid appreciably more eggs when water was the only available medium than when all sites were treated with AMF. Also, considerably more mature eggs were withheld in the AMF no-choice arena than in the no-choice test involving only water. Internal oocyte melanization was not observed in females from the oviposition arenas with the lowest oil presence (equal-choice and water-based no-choice); in contrast, this physiological response intensified as the number of AMF-treated sites increased. Female death occurred at high rates in AMF-treated environments, and this response increased with the increasing presence of such egg deposition sites. Conclusions: This study demonstrated that AMF acted as a deterrent signal to ovipositing Ae. aegypti and an indirect adulticide. Referring to its previously reported direct toxicity on the aquatic stages of this mosquito and its biodegradability, AMF should be incorporated as a critical component in integrated control strategies for dengue and related diseases.

scholarly journals Sex-specific deaths in Norway and Sweden during the COVID-19 pandemic: Did mandates make a difference?

2021 ◽  
pp. 140349482110100
Author(s):  
Ralph Catalano
Keyword(s):  
Sex Ratio ◽  
Infection Control ◽  
Temporal Variation ◽  
Risky Behavior ◽  
Control Strategies ◽  
Sex Ratios ◽  
Female Mortality ◽  
All Cause Mortality ◽  
Societal Expectations ◽  
Male To Female

Aims: To determine whether differences between Norway’s and Sweden’s attempts to contain SARS-CoV-2 infection coincided with detectably different changes in their all-cause mortality sex ratios. Measuring temporal variation in the all-cause mortality sex ratio before and during the pandemic in populations exposed to different constraints on risky behavior would allow us to better anticipate changes in the ratio and to better understand its association with infection control strategies. Methods: I apply time Box–Jenkins modeling to 262 months of pre-pandemic mortality sex ratios to arrive at counterfactual values of 10 intra-pandemic ratios. I compare counterfactual to observed values to determine if intra-pandemic ratios differed detectably from those expected as well as whether the Norwegian and Swedish differences varied from each other. Results: The male to female mortality sex ratio in both Norway and Sweden increased during the pandemic. I, however, find no evidence that the increase differed between the two countries despite their different COVID-19 containment strategies. Conclusion: Societal expectations of who will die during the COVID-19 pandemic will likely be wrong if they assume pre-pandemic mortality sex ratios because the intra-pandemic ratios appear, at least in Norway and Sweden, detectably higher. The contribution of differences in policies to reduce risky behavior to those higher ratios appears, however, small.

EFFECTS OF FLORIDA CITRUS PEST CONTROL PRACTICES ON THE CITRUS BLACKFLY (HOMOPTERA: ALEYRODIDAE) AND ITS ASSOCIATED NATURAL ENEMIES

1979 ◽  
Vol 111 (6) ◽  
pp. 731-734 ◽  
Author(s):  
George E. Fitzpatrick ◽  
Ronald H. Cherry ◽  
Robert V. Dowell
Keyword(s):  
Control Strategies ◽  
Integrated Control ◽  
Biological Control Agents ◽  
Chemical Treatments ◽  
Chronic Effects ◽  
Aleurocanthus Woglumi ◽  
Integrated Control Strategies ◽  
Florida Citrus ◽  
Amitus Hesperidum ◽  
Predator Complex

AbstractThe postbloom and summer sprays recommended in Florida commercial citrus cultures for management of insect and mite pests and phytopathogenic diseases caused a significant (P < 0.05) reduction of citrus blackfly, Aleurocanthus woglumi Ashby, infesting urban dooryard citrus. There were no observed adverse chronic effects on populations of the parasite Amitus hesperidum Silvestri, or the predator complex consisting of spiders, chrysopids, and coccinellids attributable to the chemical treatments. The absence of chronic pesticide-induced interference with biological control agents was interpreted as an indication of the potential for development of integrated control strategies against A. woglumi should this insect invade commercial citrus areas in Florida.

SIMULATION OF INTEGRATED CONTROL STRATEGIES FOR OROBANCHE SPP. BASED ON A LIFE CYCLE MODEL

2001 ◽  
Vol 37 (1) ◽  
pp. 37-51 ◽  
Author(s):  
E. KEBREAB ◽  
A. J. MURDOCH
Keyword(s):  
Seed Bank ◽  
Control Strategies ◽  
Soil Seed Bank ◽  
Integrated Control ◽  
Integrated Approach ◽  
Cultural Control ◽  
Computer Simulation Model ◽  
Weed Species ◽  
Hand Weeding ◽  
High Level

A computer simulation model was developed to investigate strategies for control of the parasitic weed species of Orobanche. The model makes use of data from published literature and predicts infestation levels in a dynamic and deterministic way. It is predicted that sustainable control of the parasite can only be achieved by reducing the soil seed bank to levels of 1000–2000 seeds m−2 and maintaining it at that level in subsequent years. When cultural control methods such as hand weeding, trap/catch cropping, delayed planting, resistant cultivars and solarization were considered individually, a relatively high level of effectiveness was required to contain the soil seed bank. An integrated approach with a selection of appropriate cultural methods is therefore recommended for further testing and validation in the field. The simulations demonstrate the importance of preventing new seeds entering the soil seed bank and that although reducing the soil seed bank may not increase yield for the first few years, it will ultimately increase production.

Research Advances in Potyviruses: From the Laboratory Bench to the Field

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Xiuling Yang ◽  
Yinzi Li ◽  
Aiming Wang
Keyword(s):  
Control Strategies ◽  
Genetic Resistance ◽  
Plant Viruses ◽  
Infection Process ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
Viral Pathogens ◽  
Genome Expression ◽  
Amount Of Knowledge

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.

The application of compound proportional resonant control strategy in multiple PV inverters system

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840098
Author(s):  
Yuan Li ◽  
Huifang Shen ◽  
Chao Xiong ◽  
Yaofei Han ◽  
Guofeng He
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Control Strategies ◽  
Integrated Control ◽  
Reference Signal ◽  
Loop Model ◽  
Harmonic Compensation ◽  
Feed Forward ◽  
Feed Forward Control ◽  
Set Up

In order to eliminate the effect on the grid current caused by the background harmonic voltage and the reference signal on the grid connected multi-inverter, this paper adopts the double closed-loop feed-forward control strategy. This strategy is based on the inductor voltage and the grid-connected current, and the integrated control strategy of quasi-proportional resonance loop parallel to a specific harmonic compensation loop. Based on the closed-loop model of multiple inverters, the change curves of the transfer function of the two control strategies are compared with the feed-forward control and the composite proportional resonance. The two corresponding control methods are used to analyze the current quality of the multi-inverter impact. Finally, the MATLAB/Simulink simulation model is set up to verify the proposed control strategies. The simulation results show that the proposed method can achieve better tracking of the sinusoidal command signal at the fundamental frequency, and enhance the anti-interference ability of the system at the 3rd, 5th, and 7th harmonic frequency.

Potassium Phosphite Mixed with Other Fungicides Reduces Yield Loss to Downy Mildew on Collard

2010 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Anthony P. Keinath
Keyword(s):  
Downy Mildew ◽  
Yield Loss ◽  
Control Strategies ◽  
Southeastern United States ◽  
Production Costs ◽  
Water Control ◽  
Economic Return ◽  
Potassium Phosphite ◽  
Full Rate ◽  
Reduced Rate

Downy mildew of collard occurs frequently in the southeastern United States, and fungicides have become an essential part of economical control strategies for the disease. Fungicides were evaluated in 2007 and 2008 either alone or combined with a reduced rate (2 pt/acre) of potassium phosphite. Two formulations of potassium phosphite also were tested alone at the full rate (4 pt/acre). Presidio, Presidio plus Pro-Phyt (2007) or K-Phite (2008), K-Phite, Amistar plus ProPhyt, and Aliette reduced downy mildew severity at the final rating and also reduced AUDPC over the two years. Presidio plus potassium phosphite and Amistar plus ProPhyt increased the weight of healthy leaves and stems over the water control and also increased economic return calculated after fungicide and other production costs were subtracted from the crop value. The yields with Ranman, Sonata, and Presidio applied in combination with potassium phosphite were 16% greater than with the fungicides applied alone. Potassium phosphite may be useful in a tank-mix with other fungicides applied to collard to prevent yield loss to downy mildew. Accepted for publication 7 July 2010. Published 23 August 2010.

scholarly journals Development of the first georeferenced map of Rhipicephalus (Boophilus) spp. in Mexico from 1970 to date and prediction of its spatial distribution

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Yazmin Alcala-Canto ◽  
Juan Antonio Figueroa-Castillo ◽  
Froylán Ibarra-Velarde ◽  
Yolanda Vera-Montenegro ◽  
María Eugenia Cervantes-Valencia ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Environmental Variables ◽  
Control Strategies ◽  
Integrated Control ◽  
Area Under The Curve ◽  
Entropy Method ◽  
Distribution Model ◽  
Economic Losses ◽  
Precipitation Seasonality ◽  
Epidemiological Risk

The tick genus Ripicephalus (Boophilus), particularly R. microplus, is one of the most important ectoparasites that affects livestock health and considered an epidemiological risk because it causes significant economic losses due, mainly, to restrictions in the export of infested animals to several countries. Its spatial distribution has been tied to environmental factors, mainly warm temperatures and high relative humidity. In this work, we integrated a dataset consisting of 5843 records of Rhipicephalus spp., in Mexico covering close to 50 years to know which environmental variables mostly influence this ticks’ distribution. Occurrences were georeferenced using the software DIVA-GIS and the potential current distribution was modelled using the maximum entropy method (Maxent). The algorithm generated a map of high predictive capability (Area under the curve = 0.942), providing the various contribution and permutation importance of the tested variables. Precipitation seasonality, particularly in March, and isothermality were found to be the most significant climate variables in determining the probability of spatial distribution of Rhipicephalus spp. in Mexico (15.7%, 36.0% and 11.1%, respectively). Our findings demonstrate that Rhipicephalus has colonized Mexico widely, including areas characterized by different types of climate. We conclude that the Maxent distribution model using Rhipicephalus records and a set of environmental variables can predict the extent of the tick range in this country, information that should support the development of integrated control strategies.

Nematodes.

2021 ◽  
pp. 270-284
Author(s):  
Regina M. D. G. Carneiro ◽  
Marcilene F. A. Santos ◽  
José Mauro C. Castro
Keyword(s):  
Life Cycle ◽  
Cover Crops ◽  
Control Strategies ◽  
Management Strategies ◽  
Genetic Resistance ◽  
Root Knot Nematodes ◽  
Meloidogyne Enterolobii ◽  
Host Status ◽  
Fruit Plants ◽  
Host Parasite

Abstract The following review of the nematodes from cultivated guava is limited to the major problem caused by M. enterolobii, its idenfication and its management strategies. The synonymization of Meloidogyne enterolobii with Meloidogyne mayaguensis and the different methods of identifying Meloidogyne species are discussed. The life cycle, host-parasite relationships, symptoms, damage and dissemination of M. enterolobii are described. The host status of cover crops, maize and fruit plants for M. enterolobii is discussed, as well as the resistance in Psidium spp. to root-knot nematodes. New prospects using genetic resistance in Brazil and some control strategies that can be used in an integrated way are presented.

Integrated Wild Oat (Avena fatua) Management Affects Spring Barley (Hordeum vulgare) Yield and Economics

1992 ◽  
Vol 6 (1) ◽  
pp. 129-135 ◽  
Author(s):  
David L. Barton ◽  
Donald C. Thill ◽  
Bahman Shafii
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Control Strategies ◽  
Integrated Control ◽  
Spring Barley ◽  
Barley Grain ◽  
Row Spacing ◽  
Wild Oat ◽  
Seeding Rate ◽  
Net Return

The effect of barley seeding rate and row spacing, and triallate, diclofop, and difenzoquat herbicide rate on barley grain yield and quality, and wild oat control were evaluated in field experiments near Bonners Ferry, Idaho, in 1989 and 1990. The purpose of the study was to develop integrated control strategies for wild oat in spring barley. Barley row spacing (9 and 18 cm) did not affect barley grain yield. Barley grain yield was greatest when barley was seeded at 134 or 201 kg ha–1compared to 67 kg ha–1. Wild oat control increased as wild oat herbicide rate increased and barley grain yield was greatest when wild oat herbicides were applied. However, barley grain yield was similar when wild oat biomass was reduced by either 65 or 85% by applications of half and full herbicide rates, respectively. Net return was greatest when the half rate of herbicide was applied to 100 wild oat plants per m2and was greatest when half or full herbicide rates were applied to 290 wild oat plants per m2. Net return increased when the seeding rate was increased to 134 or 201 kg ha–1when no herbicide was applied and when 290 wild oat plants per m2were present.

scholarly journals Evidence of Neospora caninum exposure among native Korean goats (Capra hircus coreanae)

2014 ◽  
Vol 59 (No. 12) ◽  
pp. 637-640 ◽  
Author(s):  
BY Jung ◽  
SH Lee ◽  
D. Kwak
Keyword(s):  
Neospora Caninum ◽  
Control Strategies ◽  
Integrated Control ◽  
Protozoan Parasite ◽  
Capra Hircus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Caninum Infection ◽  
One Year ◽  
And Control

Neospora caninum is a protozoan parasite that causes abortion in ruminants, including goats. The objective of the present study was to determine the seroprevalence of N. caninum in native Korean goats (Capra hircus coreanae). A commercial enzyme-linked immunosorbent assay kit was used to analyse 464 serum samples for the presence of N. caninum antibodies. Four samples (0.9%, 95% confidence intervals &ndash; CI: 0.0&ndash;1.7) were found to be positive for N. caninum antibodies. The seroprevalence was analysed according to age (less than to one year, young; more than or equal one year, adult; and unknown), sampling season (April to September, warm; October to March, cold), and region (northern, central, and southern). However, there were no statistically significant differences in seroprevalence according to age, season, and region (P &gt; 0.05). This is the first report on the seroprevalence of N. caninum in native Korean goats. The results of this study indicate a nationwide distribution of N. caninum among goats, with a relatively low prevalence. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of N. caninum infection among goats is recommended.

Sign in / Sign up

Export Citation Format

Share Document