Organic farming of maize crop enhances species evenness and diversity of hexapod predators.

Arthropod species diversity enhances ecosystem productivity and sustainability by increasing pollination and biological control services. Although, it is declining rapidly due to conventional agricultural intensification, organic agriculture with reduced reliance on agronomic inputs can regenerate ecosystems' resilience and restore them. Here, we report whether hexapod communities differ on both types of farming systems in small-scale field plot experiments, wherein Maize variety AG-589 was grown organically and conventionally in the 2020 and 2021 seasons. Livestock manure was applied in organic fields, whereas nitrogen and phosphorous were used as synthetic fertilizers in conventional fields. Hexapods were sampled three weeks after sowing once a week from the middle rows of subplots from both organically and conventionally grown maize. Twelve species of herbivores and four species of predators were recorded. Hexapod abundance overall and that of herbivores only was higher in conventionally cultivated maize, while predator abundance was higher in organic maize. Herbivores species diversity and evenness were significantly higher in conventional maize. Predator species diversity and evenness were significantly higher in organic maize fields. We noted predator abundance, diversity, and evenness as strong predictors to lower herbivore populations. These findings suggest that organic farming conserves natural enemies' biodiversity and regulates herbivores with increased provision of suitable habitats and prey resources for natural enemies, leading to enhanced relative abundance in their specialized niches. Thus, organic agriculture can potentially mediate better ecosystem services.

A molecular roadmap of definitive erythropoiesis from human induced pluripotent stem cells.

Human induced pluripotent stem cells (hiPSCs) are being considered for use in understanding haematopoietic disorders and as a potential source of in vitro manufactured red cells. Here, we show that hiPSCs are able to recapitulate various stages of developmental erythropoiesis. We show that primitive erythroblasts arise first, express CD31+ with CD235a+ , embryonic globins and red cell markers, but fail to express the hallmark red cell transcripts of adult erythropoiesis. When hiPSC-derived CD45+ CD235a- haematopoietic progenitors are isolated on day 12 and further differentiated on OP9 stroma, they selectively express CD36+ and CD235a+ , adult erythroid transcripts for transcription factors (e.g., BCL11A, KLF1) and fetal/adult globins (HBG1/2, HBB). Importantly, hiPSC- and cord-derived CD36+ CD235a+ erythroblasts show a striking homology by transcriptome array profiling (only 306 transcripts with a 2Log fold change >1·5- or 2·8-fold). Phenotypic and transcriptome profiling of CD45+ CD117+ CD235a+ pro-erythroblasts and terminally differentiated erythroblasts is also provided, including evidence of a HbF (fetal) to HbA (adult) haemoglobin switch and enucleation, that mirrors their definitive erythroblast cord-derived counterparts. These findings provide a molecular roadmap of developmental erythropoiesis from hiPSC sources at several critical stages, but also helps to inform on their use for clinical applications and modelling human haematopoietic disease.

Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae).

House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.

Outcome Of Two Column Acetabular Fractures Treated Operatively Through Single Posterior Approach.

BACKGROUND: Involvement of both columns in acetabular fractures is a common presentation; these fractures create a challenging situation for the surgeons in terms of understanding the dimensions of osseous injury and selection of surgical approach. The study was done with an objective to evaluate the efficacy of single posterior approach for acetabular fractures involving both columns directly reducing the posterior wall and column and indirectly reducing the anterior column. METHODS: An evaluation of 25 adult patients 18 male and 7 female presenting in the accident and emergency department of Khyber Teaching Hospital from December 2013 to June 2015 having acetabular fracture involving both the anterior and posterior column were included in this case series study. All patients were operated within 8 days of injury by a single operating team. Exposing and reducing the posterior acetabular column through kockerlengenbeck approach did open reduction and internal fixation with reconstruction plate and cortical screws. Additional lag screw was used to stabilize anterior column after indirect reduction with confirmation through C- arm and digital palpation through the greater sciatic notch. Patients were followed up for 6 months and Harris Hip score was evaluated after the end of the follow up period and the result was analysed. RESULTS: Majority of the patients 20 out of 25 had haris hip score more than 90 after 6 months of the operative management. CONCLUSIONS: It is suggested that acetabular that fractures involving both the acetabular columns in certain situations, may be managed by a single posterior approach as it is associated with good clinical outcome and involves lesser soft tissue complications.

RISK FACTORS LEADING TO DEVELOPMENTAL COMPLICATIONS AFTER OPEN REDUCTION IN DEVELOPMENTAL DYSPLASIA OF HIP.

BACKGROUND: The developmental dysplasia of the hip (DDH) is regarded as one of the commonest congenital deformities. Its incidence has been estimated to be one in 60 live births according to some estimates. Different forms of treatment modalities have been suggested and their success depends on the age of the patient. The study was done with the objectives to observe the post-operative complications of open reduction in patients with DDH and to determine the possible risk factors associated with these complications. METHODS: A total of 60 patients were enrolled with DDH in this descriptive cross-sectional study from August 2013 to November 2015. After obtaining an informed consent, the patients underwent open reduction and in some cases, subsequent osteotomy. The patients were followed-up at three months intervals for at least 9 months to look for development of complications, if any. RESULTS: The mean age of the patients was 31.32 ± 2.52 months. Majority 45 (75%) of the study population was female. The most common complication observed was osteonecrosis (5 patients; 8.33%) followed by residual dysplasia and re-dislocation in 3 (5%) patients each. Infection was identified as a complication in 2 (3.33%) patients. When stratified with complications of open reduction, female sex and bilateral hip involvement were found to have a significant association with the development of complications. CONCLUSION: Female sex and bilateral hip involvement confer a greater risk of developing a complication following open reduction for DDH.

Identification of plant semiochemicals and characterization of new olfactory sensory neuron types in a polyphagous pest moth, Spodoptera littoralis.

Phytophagous insects use blends of volatiles released from plants to select hosts for feeding and oviposition. To behaviorally analyze complex blends, we need efficient and selective methods for elucidating neuron types, their ligands, and specificity. Gas chromatography-combined single sensillum recordings (GC-SSRs) from antennal olfactory sensilla of female moth, Spodoptera littoralis revealed 38 physiologically active peaks in the headspace volatile blends from both larvae-damaged cotton plants and lilac flowers. Using GC-combined mass spectrometry, 9 new physiologically active compounds were identified from damaged cotton and 11 from lilac compared with earlier electrophysiological studies using antennae of female S. littoralis. We characterized 14 novel classes of olfactory sensory neurons (OSNs). Among these, we found the first 2 ligands for a frequent type of short trichoid sensillum, for which no ligands were identified earlier. By using GC-SSR, a substantial increase in functional classes of OSNs and active compounds, 40% and 34% more, respectively, compared with recent studies using GC-electroantennogram or SSR using single compounds was detected. Compared with the estimated number of corresponding antennal olfactory receptors, the OSN classes now correspond to 83% of a likely maximum. The many specialist OSNs observed may facilitate behavioral confirmation of key plant volatiles in blends.

Increased fitness and realized heritability in emamectin benzoate-resistant Chrysoperla carnea (Neuroptera: Chrysopidae).

The common green lacewing Chrysoperla carnea is a key biological control agent employed in integrated pest management (IPM) programs for managing various insect pests. A field collected population of C. carnea was selected for emamectin benzoate resistance in the laboratory and fitness costs and realized heritability were investigated. After five generations of selection with emamectin benzoate, C. carnea developed a 318-fold resistance to the insecticide. The resistant population had a relative fitness of 1.49, with substantially higher emergence rate of healthy adults, fecundity and hatchability and shorter larval duration, pupal duration, and development time compared to the susceptible population. Mean population growth rates; such as the intrinsic rate of natural population increase and biotic potential were higher for the emamectin benzoate selected population compared to the susceptible population. The realized heritability (h(2)) value of emamectin benzoate resistance was 0.34 in emamectin benzoate selected population of C. carnea. Chrysoperla species which show resistance to insecticides makes them compatible with those IPM systems where emamectin benzoate is employed.

Botanical biopesticides have an influence on tomato quality through pest control and are cost-effective for farmers in developing countries.

Synthetic insecticides heavily applied to manage agricultural pests are highly hazardous to the environment and non-target organisms. Their overuse through repeated treatments in smallholder farming communities is frequent. Botanical biopesticides are ideal for sustainable pest management in agricultural environments by keeping synthetic insecticide use at a minimum. Here we evaluated a locally prepared neem seed extract (NSE) alongside emamectin benzoate against both lepidopteran pests Helicoverpa armigera (Hübner) and Spodoptera exigua (Hübner) on tomato Lycopersicon esculentum Mill under natural field conditions in Pakistan. We compared pest severity, fruit injury, quality, marketability, and cost:benefit ratio (CBR) between treatments. The concentration of azadirachtin A in the NSE was 26.5 ppm. NSE at 2% (20 mL/L) and the emamectin benzoate at the recommended field rate in Pakistan were sprayed weekly throughout the fruiting stage. The pest larvae were significantly more abundant on fruits than on flowers and leaves. Fruit injury and losses were significantly more important in untreated control compared to NSE and emamectin benzoate treatments. NSE efficacy varied with respect to the cultivars used and the seasons. Cultivar Eden harboured more pests than Adventa, and emamectin benzoate suppressed more pest individuals than NSE. Both the insecticidal treatments were comparable in terms of marketable yield productions as well as unmarketable, uninjured, and recovered fruit yields. NSE generated a higher CBR (1: 9.26) than emamectin benzoate (1: 3.23). NSE suppressed pests by acting as an antifeedant, similar to its synthetic counterpart. Smallholder growers can thus use NSE as a cost-effective solution in tomato pest management in Pakistan.

Functional response of Harmonia axyridis preying on Acyrthosiphon pisum nymphs: the effect of temperature.

In the current study, we investigated the functional response of Harmonia axyridis adults and larvae foraging on Acyrthosiphon pisum nymphs at temperatures between 15 and 35 °C. Logistic regression and Roger's random predator models were employed to determine the type and parameters of the functional response. Harmonia axyridis larvae and adults exhibited Type II functional responses to A. pisum, and warming increased both the predation activity and host aphid control mortality. Female and 4th instar H. axyridis consumed the most aphids. For fourth instar larvae and female H. axyridis adults, the successful attack rates were 0.23 ± 0.014 h-1 and 0.25 ± 0.015 h-1; the handling times were 0.13 ± 0.005 h and 0.16 ± 0.004 h; and the estimated maximum predation rates were 181.28 ± 14.54 and 153.85 ± 4.06, respectively. These findings accentuate the high performance of 4th instar and female H. axyridis and the role of temperature in their efficiency. Further, we discussed such temperature-driven shifts in predation and prey mortality concerning prey-predator foraging interactions towards biological control.

Outcome of cervical disectomy and fusion with stabilization in single level cervical disc.

BACKGROUND: Cervical radiculopathy is a common and distressing problem. Only those patients who failed conservative treatment should undergo surgery. The anterior cervical disectomy is the procedure which offers maximal exposure of the disc space. It easily removes the portion of disc which compresses the nerve root. Possibility of developing late kyphosis from disc space collapse supported the fusion procedure after single level disectomy. The goal of instrumentation is to provide immediate stability, increase fusion rate, prevent graft failure, improve rehabilitation process and possibly no need for external orthosis. Objective of study was To see the results and complications of cervical disectomy thru anterior approach and fusion and stabilisation with titanium made plate. METHODS: This was a prospective study, comprised of 32 patients admitted during period from 2005-2008. Patients presented with radiculopathy or radiculo-myelopathy were evaluated. MRI was carried out in all the cases. Each patient was carefully evaluated to confirm clinico-radiological correlation and patients with significant disc and failure of conservative treatment were included in the study. RESULTS: Males were 28 (87.5%) and female were 4 (12.5%). Twenty patients (62.5%) were in fourth decade. C5-6 was involved in 18 (56.25%) patients. No significant postoperative complications noted. Persistent neck and back pain noted in patients in disectomy group without plating. CONCLUSION: Anterior cervical disectomy, fusion and stabilisation with plating is a safe and easy procedure in single level cervical disc disease without significant complications.

Maternal and Fetal Outcome of Pregnant Patients Having Preexisting Cardiovascular Disease.

Introduction Cardiovascular disease is common in woman of all age, including child bearing age. In this study, we aim to compare maternal and fetal outcome in pregnant woman with and without preexisting cardiovascular disease. Methods This case control single center study was conducted by Obstetrics & Gynecology department and Cardiology department Shaikh Zayed Medical College/Hospital Rahimyar Khan from 1st March 2020 to 30th June 2020. Results Pregnant woman with preexisting cardiovascular disease had more preterm births and newborn with lower birth weight. Maternal and fetal deaths were numerical higher in pregnant women with preexisting cardiovascular disease but statistically non-significant compared to woman without preexisting cardiovascular disease. Conclusion It is important to identify underlying cardiovascular disease in pregnant woman. Proper counselling throughout pregnancy is needed and efforts should be made to minimize risk of maternal and fetal complications.

Association of Leptin With Obesity and Insulin Resistance.

Introduction Leptin, a hormone released by the body to regulate energy balance by inhibiting hunger, decreases fat storage in adipocytes. Leptin is thought to play some role in obesity and insulin resistance. In this study, our aim is to see the association of leptin with obesity and insulin resistance. Methods This case-control study was conducted in a tertiary care hospital in Pakistan from January 2020 to April 2020. Ninety-two participants with BMI greater than 25 kg/m2, with no known comorbidities were enrolled in the study after informed consent. Ninety-two participants, who came to the outpatient department without a history of chronic disease, with BMI less than 25 kg/m2 were enrolled as a control group. Data were collected via self-structured questionnaires. Their blood was drawn and sent to the laboratory for cholesterol levels, insulin resistance and leptin levels. Results Serum leptin levels (51.24 ± 18.12 vs. 9.10 ± 2.99: p-value, < 0.0001), serum cholesterol levels (198.2 ± 32.1 vs. 151.2 ± 21.2, p-value < 0.0001) and insulin resistance (7.9 ± 2.1 vs. 6.3 ± 1.9, p-value < 0.0001) were higher in obese patients. Conclusion As per the results of this study, obesity was associated with increase serum leptin levels and insulin resistance. Further multi-centric studies are required to prove the possible relationship, which might help devise plans to manage obesity.

Comparison of Outcomes of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting.

Introduction Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are two common treatment options used in patients suffering from coronary artery disease. Selection and favorability of one over the other depend on individual clinical scenarios. The purpose of this study is to compare outcomes after treatment with PCI and CABG. Methods This longitudinal observational study was conducted from April 2018 to July 2019 in a cardiovascular unit of a tertiary care hospital. Participants who were eligible for revascularization were randomized either to receive stent (PCI) or surgery (CABG). Patients were then followed up for 12 months for the development of all-cause mortality and major adverse cardiovascular events (MACEs). Results At 12 months, patients randomized to the PCI group had an increased risk of repeat revascularization (21.3% vs. 7.4%; p = 0.007), whereas a similar number of patients in both groups died (3.8% vs. 3.7%), suffered myocardial infarction (7.6% vs. 5.6%), or had a cerebrovascular accident (3.8% vs. 2.8%). Conclusions This study showed that PCI had an increased risk of repeat revascularization compared to CABG. However, both had comparable significance in the development of MACEs. Nevertheless, there is a need for further study to better assess the outcomes of either, especially in the long run.

Field evaluation of synthetic and neem-derived alternative insecticides in developing action thresholds against cauliflower pests.

Synthetic chemical pesticides can enhance crop yields but also have undesired effects. Alternative 'botanical insecticides' may also have non-target effects on pollinators and biocontrol services. Employing action thresholds (ATs) can reduce pesticide (whether synthetic or botanical) use compared to fixed-interval applications. Here the azadirachtin-based botanical formulation NeemAzal and a neem seed extract (NSE) were evaluated in field spraying trials alongside commonly-used synthetics (Voliam Flexi [chlorentraniliprole plus thiamethoxam] and imidacloprid) in developing ATs for the regular and cosmopolitan cauliflower pests Brevicoryne brassicae, Plutella xylostella and Spodoptera litura. We considered the size of the S. litura larvae infesting the crop in order to derive ATs. ATs per plant were higher for NeemAzal (0.55 larvae for P. xylostella and 3 larvae for large-sized S. litura) than for Voliam Flexi (0.30 larvae for P. xylostella and 0.80 larvae for S. litura) but were similar for B. brassicae (50 individuals). Higher ATs when using azadirachtin were associated with the diverse modes of action of botanicals, for instance NeemAzal and NSE deterred oviposition of S. litura. Although the exact values of ATs are likely to have regional limits, our approach can be applied for determining ATs against common lepidopteran and aphid pests in many other vegetable crop agro-ecosystems.

Evidence of field-evolved resistance to organophosphates and pyrethroids in Chrysoperla carnea (Neuroptera: Chrysopidae).

The toxicity of some of the most commonly used insecticides in the organophosphate and pyrethroid classes were investigated against different Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) populations collected over three consecutive years (2005-2007). The populations were tested using leaf dip bioassays for residual effects and topical applications to measure the response of larvae that would come into direct contact with field application of insecticides. In leaf dip assays, the LC50 (micrograms per milliliter; 120 h) values for chlorpyrifos and profenofos were in the range of 59.3-1,023 and 180.02-1,118 respectively. The LC50 values for lambda-cyhalthrin, alphamethrin, and deltamethrin were 359.08-2,677, 112.9-923.5, and 47.81-407.03, respectively. The toxicity for the above insecticides in topical application was similar to toxicity in leaf dip assays. The susceptibility of a laboratory population, which was locally developed and designated as (Lab-PK), to deltamethrin was comparable with another susceptible laboratory population. Resistance ratios for five field populations were generally low to medium for deltamethrin, but high to very high for chlorpyrifos, profenofos, lambda-cyhalthrin and alphamethrin compared with the Lab-PK population. Our data also suggested that the five field populations had multiple resistance to two classes of insecticides. The populations showed resistance to two organophosphates tested and to lambda-cyhalthrin and alphamethrin; however, resistance to deltamethrin was only found at two locations. This pattern indicates occurrence of two divergent patterns of resistance within pyrethroids. The resistance to the insecticides was stable across 3 yr, suggesting field selection for general fitness had also taken place in various populations of C. carnea. The broad spectrum of resistance and stability of resistance to insecticides in C. carnea in the current study suggested that it could be a prime candidate for mass releases and compatible with most spray programs.

Evaluating Action Thresholds for Amrasca devastans (Hemiptera: Cicadellidae) Management on Transgenic and Conventional Cotton Across Multiple Planting Dates.

An action threshold (AT) based on the specific pest-crop relationship is an important element of integrated pest management (IPM) programs. We evaluated planting time-based ATs to manage a sucking pest, cotton leafhopper (Amrasca devastans; Hemiptera: Cicadellidae) in conventional (CIM-554) and transgenic (Bt.CIM-599) cotton cultivars under field conditions. Cultivars were planted on 15 March, April, and May during 2011 and 2012. Only two ATs (0.1 and 1.0 A. devastans per leaf) and an untreated control could be tested on 15 March planted cotton, as the populations of A. devastans never reached a density of two per leaf. Cotton planted on 15 March had the highest seed cotton yield, highest net and marginal rate of returns (MRRs) than other planting times. At this planting time, only one insecticidal application was needed at an AT of 1.0 A. devastans per leaf, with no significant yield loss. Four ATs (0.1, 1.0, 2.0, and 3.0 A. devastans per leaf) and an untreated control were tested for cotton planted on 15 April and 15 May. For the 15 April planting, 2.0 AT led to 3 applications as compared with 10 applications needed with 0.1 AT; without any significant yield loss, generating the highest net return and MRR for this planting date. The 15 May planting was more vulnerable to A. devastans damage and 1.0 AT generated the highest net return and MRR with four applications as compared with all other ATs. These results suggest that the use of planting time-based ATs can improve cotton yield through cost-effective applications of insecticides.

Root order-based traits of Manchurian walnut & larch and their plasticity under interspecific competition.

Manchurian walnut and larch are key timber species of northeast China but information on (fine) root traits of both species is scarce. Plasticity of root traits in mixed plantations has been studied rarely although this could give important insights into mechanisms of root competition. This study examined root traits by branching order in 30-yr-old monocultures and their plasticity in mixed plantations. In monocultures, Manchurian walnut and larch differed in key fine root traits. Larch roots hold more absorptive root orders, larger diameter and lower specific root length/area. Walnut root orders featured greater cortex:stele ratios, N-concentrations and respiration rates. Under interspecific competition, the proportion of walnut root tips increased, the biomass/length of larch root orders 1-3 decreased. Larch possessed a greater morphological and anatomical plasticity of terminal root orders than walnut. Mycorrhizal colonization rates of walnut were reduced. Both species differed fundamentally in their fine root properties. Absorptive fine root orders reacted plastic under interspecific competition while traits of higher root orders remained unchanged. In mixture, larch roots possessed a greater plasticity in traits related to resource uptake (efficiency) than walnut roots whose reaction norm is suggested to be predominantly based on interference competition via juglone exudation.

Patterns of genetic differentiation among populations of Amrasca biguttula biguttula (Shiraki) (Cicadellidae: Hemiptera).

Cotton leafhopper, Amrasca biguttula biguttula (Shiraki), a serious sucking insect pest of cotton and vegetables is present throughout South and Southeast Asia. Genetic differentiation within A. biguttula biguttula populations collected from 16 cotton growing areas of Punjab, Pakistan, was examined by sequencing the barcode region of the mitochondrial cytochrome oxidase subunit 1 (COI) gene. The dendrogram obtained by neighbour joining analysis of COI sequences confirmed the presence of single species of cotton leafhopper. The overall average pairwise divergence was 0.01. Very little variation was found among populations from cotton growing areas of Punjab, Pakistan and these were most similar to populations from North India. South Indian populations were grouped together and were generally more divergent. Extensive migration of this pest species among cotton-growing areas in the Indian subcontinent may hinder genetic diversification of cotton leafhopper. Four Pakistani samples of cotton leafhopper tested positive for Wolbachia infection but were not clearly differentiated from non-Wolbachia infected samples, suggesting that Wolbachia did not cause reproductive incompatibilities.

Field evolved resistance to pyrethroids, neonicotinoids and biopesticides in Dysdercus koenigii (Hemiptera: Pyrrhocoridae) from Punjab, Pakistan.

The red cotton bug, Dysdercus koenigii (Fabricius) is an important emerging economic pest of cotton, Gossypium hirsutum Linnaeus in Pakistan. Insecticides are the primary management tactics to suppress populations of this pest. However, resistance to insecticides evolves due to substantial and repeated applications. The resistance to pyrethroids, neonicotinoids and biopesticides have been evaluated in many pests worldwide, nevertheless lack of information in D. koenigii. Therefore, the aforementioned insecticide resistance in five field populations of D. koenigii collected from Multan, Makhdoom Rashid, Jahanian, Lodhran and Vehari districts of Punjab, Pakistan during 2015-2017 was determined by using seed dip method. Based on the present results, D. koenigii has developed moderate to very high resistance to acetamiprid (RR = 33-433) and imidacloprid (RR = 21-173), low to high resistance to emamectin benzoate (RR = 14-52), and very low to high resistance to spinosad (RR = 4.13-54), compared to the susceptible population. However, all field populations of D. koenigii remained susceptible to deltamethrin (RR = 0.62-2.17) and lambda-cyhalothrin (RR = 0.91-1.97). A rotational use of pyrethroids with provision of other integrated pest management tactics is recommended to manage insecticide resistance in D. koenigii.

Eugenol, a Plant Volatile, Synergizes the Effect of the Thrips Attractant, Ethyl Iso-Nicotinate.

The onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), is a polyphagous pest that causes serious damage to agricultural crops, vegetables, and ornamental plants worldwide. Farmers rely on the extensive usage of synthetic chemical insecticides to control T. tabaci. There is a dire need to develop alternative control strategies to overcome the problems posed by chemical insecticides. Efficient traps would allow sensitive monitoring and possibly mass trapping. A field experiment was conducted to evaluate the potential of three plant compounds with known release rates (ranging from 6-30 mg/d); eugenol (Eug), 1, 8-cineole (eucalyptol), and linalool in all possible combinations with a thrips attractant, ethyl iso-nicotinate (EI). A combination of EI with Eug increased the effect of EI by attracting 100% more thrips (effect size, 1.95) as compared to the control of EI alone. Catches in remaining treatments were lower and or not significantly different from EI alone. The results from our study could be used to develop improved volatile blends to be used for monitoring traps. Our data suggests that these traps could be effective even at very low populations.