Control Tactics Research Articles

Children are victims of industrialization and commercialization of early feeding practices: A review of obesity in preschool children in Egypt

Introduction: Obesity Is Global Problem Which Begins From Early Childhood. Early Exclusive Breastfeeding (EBF) without foods or Milk Formula (MF) before 6 months, with continued breastfeeding for two years are optimal feeding practices. Aim: To review studies conducted to assess the nutritional status of preschool children with a focus on obesity and stunting and their association with EBF vs MF feeding. Methods: We used online search engines of the Egyptian university libraries consortium (www.eulc.edu) to search for studies on overweight, obesity stunting and wasting in preschool children. We identified 919 theses that were filtered to 32 studies then to 18 theses fitting the criteria of the study. Analysis of the pooled data was done for the studies with children who were EBF (2 studies) vs children who were exposed to MF (16 studies) by age and sex. Findings: Pooled analysis for children aged 6-59 months among MF vs. EBF studies as follows: overweight 5.4% vs. 3.45%, obesity 13.8% vs. 5.65%, stunting 21.6% vs. 1.15% and wasting 9.7% vs. 0.85% respectively. Obesity and overweight were higher in males in both studies, whereas stunting and wasting were higher in females in both studies (ages 0-72 months). Early and extended MF feeding, foods before 6 months of life, chips and canned drinks were prominent risk factors for obesity. Large family size was associated with obesity and short birth interval with stunting. Colostrum feeding, longer duration of breastfeeding, fruits and vegetables were protective. Obese children showed clinical signs of anemia, vitamin A and D deficiency, severe asthma and developmental delay. Conclusions: Obesity and MF feeding beyond 6 months and well into 5 years of age threaten child health. Policies and legislations are needed to control, counter and monitor marketing tactics supported by guiding messages. Keywords: Obesity; overweight; stunting; wasting; fast foods; breastfeeding; birth spacing; child development; infancy; preschool children; anthropometry; growth.

Quantized intermittent control tactics for exponential synchronization of quaternion-valued memristive delayed neural networks

This article studies the global exponential synchronization (GES) of quaternion-valued memristive delayed neural networks (QVMDNNs) by quantized intermittent control (QIC). Without decomposing the original systems into usual real-valued or complex-valued ones, the discussed system is directly processed in both cases of the differential inclusion theory. Based on two QIC strategies and applying Lyapunov functional method and inequality techniques, several new delay-dependent criteria in the form of real-valued algebraic inequalities are directly derived to assure the GES of the concerned system. Compared to the traditional feedback control, the QIC strategy can reduce the control expenses and shorten time to achieve the GES. Ultimately, two examples are given to validate the effectiveness and advantages of the proposed outcomes.

Effectiveness of glufosinate, dicamba, and clethodim on glyphosate-resistant and -susceptible populations of five key weeds in Australian cotton systems

AbstractXtendFlexTM cotton with resistance to glyphosate, glufosinate, and dicamba may become available in Australia. Resistance to these herbicides enables two additional modes of action to be applied in crop. The double-knock strategy, typically glyphosate followed by paraquat, has been a successful tactic for control of glyphosate-resistant cotton in fallow situations in Australia. Glufosinate is a contact herbicide and may be useful as the second herbicide in a double knock for use in XtendFlexTM cotton crops. We tested the effectiveness of glufosinate applied at intervals of 1, 3, 7, and 10 d after initial applications of glyphosate, dicamba, clethodim, and glyphosate mixtures with dicamba or clethodim on glyphosate-resistant and glyphosate-susceptible populations of flaxleaf fleabane, common sowthistle, feather fingergrass, windmill grass, and junglerice. Effective treatments for flaxleaf fleabane with 100% control were dicamba and glyphosate+dicamba followed by glufosinate independent of the interval between applications. Common sowthistle was effectively controlled in Experiment 1 by all treatments. However, in Experiment 2, effective treatments were dicamba and glyphosate+dicamba followed by glufosinate (99.3% to 100% control). Timing of the follow-up glufosinate did not affect the control achieved. Consistent control of feather fingergrass was achieved with glyphosate, clethodim, or glyphosate+clethodim followed by glufosinate at 7-d and 10-d intervals (99.7% to 100% control). Control of feather fingergrass was inconsistent. The best treatment for windmill grass was glyphosate+clethodim followed by glufosinate 10 d later (99.8% to 100% control). Junglerice was effectively controlled with all treatments except for glyphosate on the glyphosate-resistant population. Additional in-crop use of glufosinate and dicamba should be beneficial for weed management in XtendFlexTM cotton crops, when using the double knock tactic with glufosinate. For effective herbicide resistance management, it is important that these herbicides be used in addition to, rather than substitution for, existing weed management tactics.

Implementation of quasi Z-source inverter for renewable energy applications

This paper discusses the analysis of a Quasi Z source inverter with a trouble-free boost control tactic for renewable energy applications. The non-availability of uninterrupted renewable energy sources in atmosphere weather conditions raises variation in output voltage and currents. This may affects the performance of conventional inverters with potential source (VSI), current source connected (CSI) and impedance source inverter (ZSI). To overcome the drawback of VSI, CSI and ZSI a quasi-Z source inverters (QZSI) are used. The QZSI performs multiple operations such as DC-to-DC, AC-to-AC, AC-to-DC and DC- to-AC conversions. Also, it may be used for each buck and boost operation, using the shoot through state. The QZSI is derived from the ZSI topology, with a minor modification of the impedance network and overcomes the troubles facing in ZSI. The design construction and simulation study of quasi-Z source inverter is performed using MATLAB/Simulink environment.

Linguistic Indicators of Coercive Control: Evidenced in Sex Trafficking Narratives

Prior research on coercive control has focused on coercive behavioral tactics to better understand how coercion is exacted in abusive relationships. Furthering this body of research, this study extends coercive behavior to the linguistic domain, by examining the linguistic correlates of long-term coercive relationships. Using transcripts of wiretapped conversations, spanning a 2-year period, between two pimps and four women they sexually exploited, this study examined the distinct linguistic manifestation of asymmetric power in commercial sexual exploitation. Our findings suggest a complementary linguistic dimension to the commonly reported behavioral repertoire of coercive control tactics. Specifically, the victims consistently complied with the microregulation and surveillance presumed by their pimps by engaging in discursive overelaboration. This overelaboration often included details of their location, activity, and timing—and were designed to justify those as work-and profit-relevant. This pattern of pre-emptive, unsolicited overelaboration that the commercial sexually exploited women exhibited toward their pimps was almost nonexistent in their personal conversations with other individuals. These results open the opportunity for the indirect measurement of interpersonal abuse, making it less dependent on explicit physical abuse and more broadly situated within the coercive environment.

Attraction of Brown Marmorated Stink Bugs, Halyomorpha halys, to Blooming Sunflower Semiochemicals.

The polyphagous invasive brown marmorated stink bug, Halyomorpha halys, reportedly discriminates among phenological stages of host plants. To determine whether olfaction is involved in host plant stage discrimination, we selected (dwarf) sunflower, Helianthus annuus, as a model host plant species. When adult females of a still-air laboratory experiment were offered a choice of four potted sunflowers at distinct phenological stages (vegetative, pre-bloom, bloom, seeding), most females settled onto blooming plants but oviposited evenly on plants of all four stages. In moving-air two-choice olfactometer experiments, we then tested each plant stage versus filtered air and versus one another, for attraction of H. halys females. Blooming sunflowers performed best overall, but no one plant stage was most attractive in all experiments. Capturing and analyzing (by GC-MS) the headspace odorants of each plant stage revealed a marked increase of odorant abundance (e.g., monoterpenes) as plants transitioned from pre-bloom to bloom. Analyzing the headspace odorant blend of blooming sunflower by gas chromatographic-electroantennographic detection (GC-EAD) revealed 13 odorants that consistently elicited responses from female H. halys antennae. An 11-component synthetic blend of these odorants attracted H. halys females in laboratory olfactometer experiments. Furthermore, in field settings, the synthetic blend enhanced the attractiveness of synthetic H. halys pheromone as a trap lure, particularly in spring (April to mid-June). A simpler yet fully effective sunflower semiochemical blend could be developed and coupled with synthetic H. halys aggregation pheromones to improve monitoring efforts or could improve the efficacy of modified attract-and-kill control tactics for H. halys.

Psychometric Properties of the Coercion in Intimate Partner Relationships Scale.

Coercive control is defined as the systematic use of demands, threats, and surveillance behaviors to gain control over an individual. Content validity appears to be an issue for existing measures of coercive control tactics, as they do not assess all of these behaviors. This study investigated the validity and reliability of the Demand, Threat, Surveillance, and Response to Demands subscales of the Coercion in Intimate Partner Relationships (CIPR) scale. Participants (N = 541) completed online measures of coercive control, physical intimate partner violence, depression, and posttraumatic stress disorder symptomatology. Confirmatory factor analyses, linear regressions, and correlational analyses investigated the construct (i.e., concurrent, convergent, and discriminant) validity of the CIPR subscales. Internal consistency of the subscales and test-retest reliability were also examined. Results provided support for the validity and reliability of the CIPR. Implications and usage of the CIPR in research and practice are discussed. We report how we determined our sample size, all data exclusions, all manipulations, and all measures in the study.

Microsatellite variation in Helicoverpa gelotopoeon (Lepidoptera: Noctuidae) populations from Argentina

Abstract Helicoverpa gelotopoeon (Dyar) (Lepidoptera: Noctuidae) is a polyphagous pest that has been reported causing damage in many agricultural crops such as soybean, chickpea and cotton. This species, together with Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner) and Chloridea virescens (Fabricius), belongs to the Heliothinae complex of economic importance in Northwestern Argentina. Many species in the Heliothinae subfamily have developed resistance to insecticides and insecticidal proteins from Bacillus thuringiensis (Bt). Managing resistance to these control tactics in H. gelotopoeon is of high importance and dependant on knowledge of population genetics of this species. The objective of this study was to evaluate the genetic variability and structure of H. gelotopoeon populations from different host plants and geographic regions of Argentina. Towards this goal, six microsatellite loci were screened across 196 individuals. The results obtained revealed high genetic diversity and lack of clear structure among the populations of H. gelotopoeon studied. This genetic homogeneity between populations from different geographical regions and hosts could be attributed to the long‐range migratory capacity of Heliothinae and the generalist behaviour of H. gelotopoeon.

Lethal and Sublethal Effects of Conventional and Organic Insecticides on the Parasitoid Trissolcus japonicus, a Biological Control Agent for Halyomorpha halys.

The egg parasitoid Trissolcus japonicus is a natural enemy of Halyomorpha halys, a polyphagous invasive pest in Europe and North and South America. Integration of chemical and biological control tactics could facilitate effective and sustainable integrated pest management programs. This study was conducted to assess (i) the lethal effects of field rates, (ii) the sublethal effects of maximum and half field rates, and (iii) the lethal effects of different routes of exposure of three organic and two conventional insecticides against T. japonicus. Maximum field rates of spinosad and sulfoxaflor resulted in acute lethal toxicity to adult T. japonicus 1 week after residual contact exposure. Maximum and half field rates of pyrethrins, the mixture of azadirachtin and pyrethrins, and clothianidin caused sublethal effects to female wasps through residual contact exposure. Furthermore, all insecticides caused acute lethal effects 1 week after ingestion by unmated female wasps. Taken together, these results suggest that careful planning is necessary to ensure compatibility between biological and chemical control for H. halys. The insecticides evaluated in this study varied in toxicity to T. japonicus and should be used with caution to conserve this natural enemy for biological control of H. halys.

A Review of Alternative Management Tactics Employed for the Control of Various Cockroach Species (Order: Blattodea) in the USA.

Simple SummarySome cockroaches that live within and around human environments are considered pests of public health importance because they can carry and transfer human pathogenic microorganisms to food and food handling surfaces; infestations could result in cockroach allergen-induced allergic sensitization and asthma in sensitized individuals. In addition, cockroaches can cause psychological stress and stigma in people living in infested locations. Historically, cockroach control has been based on the use of insecticide sprays. However, in certain situations, sole dependence on insecticides for cockroach control can lead to issues such as pesticide resistance evolution and raises public concern due to the impact on the environment and human health. To overcome these problems, the use of reduced risk insecticide options (e.g., baits) and their combined use with alternative tactics is recommended. This review aims to examine alternative tactics used for cockroach control, with emphasis on those that are proven to be efficacious, and/or have potential for their incorporation in management programs of important domestic and peridomestic cockroaches in the USA. Remarkable examples of successful cockroach control programs are those that educate the public, promote cleanliness and hygiene, use traps to monitor infestation levels and utilize insecticide baits.Effective control of domestic and peridomestic cockroaches requires integrated approaches that emphasize concurrent use of chemicals with alternative control tactics. An integrated pest management (IPM) approach is particularly justified in environments where satisfactory cockroach control cannot be achieved due to multiple factors including development of insecticide aversion and resistance in some cockroach species, and poor sanitation or structural issues that foster infestations. While a flurry of research effort has been devoted to study alternative tactics for cockroach control, only a few of them have been evaluated in the context of IPM programs. This review focuses on examining studies on alternative tactics that are proven efficacious, economical, and logistically feasible for their inclusion in IPM programs for important domestic and peridomestic cockroaches in the USA. Management programs that educate the public on cockroach biology, behavior, and the importance of sanitation; use of traps to monitor infestation levels; apply targeted low impact insecticides such as baits, have demonstrated a greater success for effective and sustainable control of cockroaches when compared to an insecticide-only approach. Incorporation of other alternative control methods to IPM programs will require more applied research that validates their use in real-world scenarios and demonstrates their cost-effectiveness.

Control tactics and evaluation of clinical efficacy of therapy in children with bronchial asthma associated with mycoplasma infection

The uncontrolled course of bronchial asthma (BA) in children and insufficient efficacy of standard therapy regimens may be due to underestimated infectious factors. The objective: to study specific parameters of the course and treatment of mycoplasma infection, improve monitoring over BA therapy in children of the tender and preschool age. Subjects and methods. 320 children with BA in the age from 1 to 7 years old were followed up. In this work, Mycoplasma pneumoniae (FH), Mycoplasma hominis (H-34), Ureaplasma urealyticum (serotype 8), Mycoplasma fermentans (PG18) and Mycoplasma arthritidis (PG6) were used, they were cultured on a liquid medium for cultivation of mycoplasmas and ureaplasmas. To isolate CIC from blood serum samples, we used the method of precipitation with 3.5% polyethylene glycol (PEG, 6000 Da), hemagglutination assays and IFA were used to identify mycoplasma antigens, mycoplasma DNA was detected by PCR with InterLabService diagnostic kits. The data of 47 patients with prolonged mycoplasma antigenemia were assessed at the baseline and in 1.5-3 months after the treatment course of azithromycin.Results. 320 blood serum samples from children with BA were tested, and the detection rate by hemagglutination assays of M. pneumoniae antigens was 60.9%, M. hominis – 43.4%, U. urealyticum – 44.8%, M. arthritidis – 29.7%, M. fermentrans – 45.3%. The assessment of relationship between of M. pneumoniae, M. hominis and asthma exacerbation showed that antigens of M. pneumoniae and M. hominis were found in 216 children (single or associated). After treatment with azithromycin, the frequency of BA exacerbations within 3 months decreased by 2.4 times, as well as there was a reduction in the number of samples positive for antigens and DNA of mycoplasma in a free state and within CIC. The persistence of antigens, DNA of M. pneumoniae and M. hominis before treatment of 47 children was 80.9 and 66.0% of cases, after treatment with azithromycin – 31.9 and 25.5% of cases, respectively (p < 0.001). Within CIC isolated from the blood serum of patients, antigens to M. pneumoniae and M. hominis before treatment were detected by IFA in 63.8 and 70.2% of children, after treatment – in 31.9 and 23.4%, respectively. p < 0.001. In blood samples, DNA of M. pneumoniae and M. hominis was detected by PCR before treatment in 8.5 and 34.0%; after treatment in 6.4% (p = 0.318) and 19.1% of cases, respectively (p = 0.009), and within CIC isolated from blood serum, in 27.7 and 48.9% of cases before treatment and 8.5 and 34.0% after it, respectively (p = 0.009).

Predatory Policing, Intersectional Subjection, and the Experiences of LGBTQ People of Color in New Orleans

Much of the disparate outcomes experienced by lesbian, gay, bisexual, transgender, queer, and other identities along the spectrum (LGBTQ+) people of color are directly linked to the practices of public actors and through institutional policies. This is perhaps no truer than for LGBTQ+ individuals of color in their interactions with police. This article argues that intersectional subjection fosters an environment prime for predatory policing and uses it as a framework to examine perceptions of predatory policing practices and its role in the exploitation of LGBTQ+ people of color in New Orleans. Research findings suggest that participants perceive predatory policing as part of the everyday practices of the New Orleans Police Department, where modes of power and social control tactics are regularly used to maintain systems of oppression. Ultimately, the goal of this project is to use the lived experience to explore the presence of predatory policing to understand how it has contributed to the marginalization of LGBTQ+ identifying individuals of color.

Interactions Between Tsetse Endosymbionts and Glossina pallidipes Salivary Gland Hypertrophy Virus in Glossina Hosts.

Tsetse flies are the sole cyclic vector for trypanosomosis, the causative agent for human African trypanosomosis or sleeping sickness and African animal trypanosomosis or nagana. Tsetse population control is the most efficient strategy for animal trypanosomosis control. Among all tsetse control methods, the Sterile Insect Technique (SIT) is one of the most powerful control tactics to suppress or eradicate tsetse flies. However, one of the challenges for the implementation of SIT is the mass production of target species. Tsetse flies have a highly regulated and defined microbial fauna composed of three bacterial symbionts (Wigglesworthia, Sodalis and Wolbachia) and a pathogenic Glossina pallidipes Salivary Gland Hypertrophy Virus (GpSGHV) which causes reproduction alterations such as testicular degeneration and ovarian abnormalities with reduced fertility and fecundity. Interactions between symbionts and GpSGHV might affect the performance of the insect host. In the present study, we assessed the possible impact of GpSGHV on the prevalence of tsetse endosymbionts under laboratory conditions to decipher the bidirectional interactions on six Glossina laboratory species. The results indicate that tsetse symbiont densities increased over time in tsetse colonies with no clear impact of the GpSGHV infection on symbionts density. However, a positive correlation between the GpSGHV and Sodalis density was observed in Glossina fuscipes species. In contrast, a negative correlation between the GpSGHV density and symbionts density was observed in the other taxa. It is worth noting that the lowest Wigglesworthia density was observed in G. pallidipes, the species which suffers most from GpSGHV infection. In conclusion, the interactions between GpSGHV infection and tsetse symbiont infections seems complicated and affected by the host and the infection density of the GpSGHV and tsetse symbionts.

Fitness Cost of Chlorpyrifos Resistance in Spodoptera frugiperda (Lepidoptera: Noctuidae) on Different Host Plants.

Spodoptera frugiperda (J. E. Smith, 1797) is a polyphagous pest of global relevance due to the damage it inflicts on agricultural crops. In South American countries, this species is one of the principal pests of maize and cotton. Currently, S. frugiperda is also emerging as an important pest of soybeans and winter cereals in Brazil. Chemical control is one of the main control tactics against S. frugiperda, even though resistance against numerous modes of action insecticides has been reported. To support insect resistance management programs, we evaluated the fitness costs of resistance of S. frugiperda to the acetylcholinesterase inhibitor chlorpyrifos. Fitness costs were quantified by comparing biological parameters of chlorpyrifos-resistant and -susceptible S. frugiperda and their F1 hybrids (heterozygotes) on non-Bt cotton, non-Bt maize, non-Bt soybean, and oats. The results revealed that the chlorpyrifos-resistant genotype showed lower pupa-to-adult and egg-to-adult survivorship and reduced larval weights on oats; longer neonate-to-pupa and egg-to-adult developmental periods, and lower pupal weights and fecundity on maize; lower pupal weights on soybean; and reduced fecundity on cotton compared with the chlorpyrifos-susceptible genotype. Fitness costs also affected fertility life table parameters of the resistant genotype, increasing the mean length of a generation on cotton and maize and reducing the potential for population growth on all hosts. These findings suggest fitness costs at the individual and population levels of chlorpyrifos resistance in S. frugiperda, indicating that removal of the selective agent from the environment would result in reduced resistance and opportunities for the restoration of susceptibility.

Design and Performance Analysis of a PV Control Scheme to Improve LVRT of Hybrid Power System.

Solar power stations worldwide have been rising every year as well as the usage of sustainable power has increased. The addition into the traditional electricity grid networks of renewable sources such as the photovoltaic (PV) system is an essential challenge, given its erratic power generation. The major issue is to detach PV from the faulty grid, which leads to fluctuation in the system's interconnected PV system and system-wide energy interruptions. The low voltage ride through (LVRT) enables the PV scheme should stay linked to the grid even under fault situations in short periods and must assist the grid return to regular situations according to the modern grid codes. Hence, this paper develops and analyzes five aspects of control strategy to increase PV station's LVRT capability. The in-depth simulation of the independent units of the grid-connected large-scale PV farm is accomplished using PSCAD/EMTDC to assess the feasibility of the suggested control tactic for the modified IEEE nine-bus system.

IPM Toolkit Preservation

AbstractIntegrated pest management (IPM) is a holistic approach that considers all farming practices and control tactics to discourage the development of economically damaging pest populations with a focus on preventing and managing pest populations as opposed to single interventions to eliminate pests once a problem has occurred. The idea of the IPM toolkit analogy is to keep as many tools in the toolbox as possible to manage agricultural pests; the more tools available, the better chance of providing a solution to a given pest threat. Preserving these tools is critically important to IPM. This article is the second in the three‐part series in Crops & Soils magazine. It is part of an American Society of Agronomy training series sponsored by the Kellogg Company. Earn 1 CEU in Integrated Pest Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/983.

Experimentally guided development of a food bait for European fire ants

AbstractDeployment of lethal food baits could become a control tactic for the invasive European fire ant (EFA), Myrmica rubra L. (Hymenoptera: Formicidae), because foraging ants carry the lethal food to their nest and share it with their nest mates, ultimately causing the demise of nests. Our objective was to develop a food bait that elicits a strong foraging response from EFAs, has extended shelf life, and is cost‐effective to produce. To develop a bait composition with ‘ant appeal’, we ran two separate field experiments testing pre‐selected carbohydrate sources (oranges, apples, bananas) and protein/lipid sources [tuna, pollen, sunflower seeds, mealworms (Tenebrio molitor L., Coleoptera: Tenebrionidae)]. Whereas foraging EFAs responded equally well to the three types of carbohydrates, they preferred mealworms to all other protein/lipid sources. In a follow‐up laboratory experiment, the combination of apples and mealworms elicited a stronger foraging response from EFAs than either apples or mealworms alone. To help reduce bait ingredient costs, we tested house crickets, Acheta domesticus (L.) (Orthoptera: Gryllidae), as a less expensive mealworm alternative and found crickets and mealworms comparably appealing. Addressing the shelf life of baits, we tested freeze‐dried and heat‐dried apple/cricket combinations. Rehydrated freeze‐dried baits proved as appealing as fresh baits and superior to rehydrated heat‐dried baits, suggesting that freeze‐drying may retain essential nutrients and/or aroma constituents. Insecticide‐laced baits had no off‐putting effect on foraging responses of worker ants and caused significant mortality. As freeze‐drying is expensive, further research should investigate the preservation of moist food baits or the development of dry baits that are hydrated prior to deployment.

Sequential and Binomial Sampling Plans to Estimate Thrips tabaci Population Density on Onion.

Simple SummaryThrips are tiny insects that cause significant damage to onion crops worldwide. They feed on the plants and can also transmit plant viral diseases. To prevent damage, it is necessary to estimate the population density (average number of insects per plant), through periodic sampling, and to apply a combination of control tactics to maintain thrips at acceptable levels. Conventional sampling methods are precise but require large investments of time and effort. In this study, binomial and sequential sampling plans were developed to estimate thrips population density in a precise and less time-consuming manner. More than 50 onion plots were sampled, and Thrips tabaci Lindeman was identified as the predominant pest species. The sampling plans reached acceptable levels of precision (D = 0.25) in less time than conventional sampling. Binomial and sequential sampling plans were reliable and easily implemented in practice, but sequential sampling showed better performance than binomial sampling under different field conditions. These findings may help to reduce time and work for T. tabaci sampling and, consequently, improve implementation of crop protection tactics on onion.Thrips tabaci Lindeman is a worldwide onion pest that causes economic losses of 10–60%, depending on many factors. Population sampling is essential for applying control tactics and preventing damage by the insect. Conventional sampling methods are criticized as time consuming, while fixed-precision binomial and sequential sampling plans may allow reliable estimations with a more efficient use of time. The aim of this work was to develop binomial and sequential sampling for fast reliable estimation of T. tabaci density on an onion. Forty-one commercial 1.0-ha onion plots were sampled (sample size n = 200) to characterize the spatial distribution of T. tabaci using Taylor’s power law (a = 2.586 and b = 1.511). Binomial and sequential enumerative sampling plans were then developed with precision levels of 0.10, 0.15 and 0.25. Sampling plans were validated with bootstrap simulations (1000 samples) using 10 independent data sets. Bootstrap simulation indicated that precision was satisfactory for all repetitions of the sequential sampling plan, while binomial sampling met the fixed precision in 80% of cases. Both methods reduced sampling time by around 80% relative to conventional sampling. These precise and less time-consuming sampling methods can contribute to implementation of control tactics within the integrated pest management approach.

Detection of Phosphine Resistance in Field Populations of Four Key Stored-Grain Insect Pests in Pakistan.

Simple SummaryThe resistance of coleopteran stored-product pests to phosphine fumigation is becoming a global phenomenon. However, there is limited literature available and a lack of knowledge on this issue in Pakistan. Thus, in the current study, we estimated the status of phosphine resistance among ten populations of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), Sitophilus granarius (L.) (Coleoptera: Curculionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Trogoderma granarium Everts (Coleoptera: Dermestidae), originated from different regions of Pakistan. Laboratory-susceptible populations of all insect species were also considered in the tests. Concentration–response bioassays were conducted for each insect species. All of the tested populations of each species were found to be resistant to phosphine. However, they varied with regard to their levels of resistance. Overall, R. dominica exhibited the highest resistance level, followed by T. castaneum, T. granarium and S. granarius. Although phosphine is effective against several stored-product pests, the development of resistance may lead to failures in its application in Pakistan.In Pakistan, the control of stored-product insect pests mainly relies on the use of phosphine gas along with other control tactics. The aim of this study was to determine the level of phosphine resistance among ten differently located populations of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae). Laboratory-susceptible populations of all insect species were also considered in the experiments. Concentration–response bioassays were conducted for each species. All of the tested populations (10 out of 10) of each species were found to be resistant to phosphine, but varied in their level of resistance. Probit analysis estimated LC50 at 2.85, 1.90, 2.54 and 2.01 ppm for laboratory-susceptible populations of R. dominica, S. granarius, T. castaneum and T. granarium, respectively. Against R. dominica, the highest and lowest resistance levels were observed in the Rahim Yar Khan (LC50 at 360.90 ppm) and Rawalpindi (LC50 at 210.98 ppm) populations, respectively. These resistant populations were 126.67- and 74.02-fold more resistant than the laboratory population. The Multan and Lahore populations of S. granarius exhibited the maximum (LC50 at 122.81 ppm) and minimum (LC50 at 45.96 ppm) resistance levels, respectively, i.e., they were 64.63- and 24.18-fold more resistant than the laboratory population. The Layyah population of T. castaneum showed the maximum resistance level (LC50 at 305.89 ppm) while the lowest was observed in the Lahore population (LC50 at 186.52 ppm), corresponding to 120.42- and 73.43-fold more resistant than the laboratory population, respectively. Regarding T. granarium, the Layyah population showed the maximum resistance level (LC50 at 169.99 ppm) while the Lahore population showed the minimum resistance (LC50 at 74.50 ppm), i.e., they were 84.57- and 37.06-fold more resistant than the laboratory population, respectively. Overall, R. dominica presented the highest resistance level, followed by T. castaneum, T. granarium and S. granarius. The current study suggests that the application of phosphine may not be an adequate control strategy for the management of the above tested insect pests in Pakistan.

Adaptive tracking control of stochastic switched nonlinear systems with unknown dead‐zone output

AbstractIn this article, the problem of adaptive output feedback control is carried out for stochastic switched nonlinear systems with dead‐zone output and asymmetric tracking constraints. A type of smooth approximate model is proposed, which unfastens the nondifferentiable phenomena of dead‐zone output. The Nussbaum‐type function is utilized to develop the control design of the unknown dead‐zone output. Subsequently, an improved first‐order filter is cooperated into the barrier Lyapunov function analysis, which avoids the repeated derivative problem of virtual control inputs in the backstepping design procedure and completes the control design successfully. The proposed constructive control algorithm can achieve the control goal well. Finally, a numerical example with comparison results is given to further verify the validity of the new control tactic.