Use Of Insecticides Research Articles

Long-Lasting Insecticidal Net Ownership and Use in Mogode Health District, Cameroon.

Cameroon is a malaria-endemic country. Many control strategies including long-lasting insecticidal nets (LLIN) have been proposed to reduce the burden of malaria. The World Health Organization aims to achieve at least 80% of people sleeping under a LLIN. This study assessed the ownership and use of LLNs in the Mogode Health District (MHD). A community-based cross-sectional study was conducted in MHD in September 2021. Data on ownership and LLINs use were collected using structured questionnaires following the Roll Back Malaria guidelines. Univariate and multivariate analyses were performed to assess the determinants of ownership and failure to LLIN use. A total of 332 households were included from eight health areas. The proportion of households with at least one LLIN was 72.0% (238). However, 232 (70.0%) reported having used LLIN (sleeping under LLIN the previous night). Household heads with higher education were six times more likely to have owned LLINs than those with no education (adjusted odds ratio (AOR)=6.8; confidence interval (CI) 1.5, 31.0, p< 0.05). Additionally, household heads between the ages of 36-50 were 4.2 times (AOR= 4.2, CI 1.3-13.8, p< 0.05) likely to fail to use LLINs in households. However, households where heads had secondary education (AOR= 0.2, CI 0.1-0.6, p< 0.05), were negatively associated with failure to use LLINs. Ownership and use of LLINs in MHD remain challenging. Therefore, this finding will contribute to improving recommendations and updating strategies such as targeted messages aimed at raising awareness of malaria during mass LLIN distribution campaigns.

Indigenous Knowledge in Termite Management of Agricultural Crops – A Review

Some species of termites are becoming a threat to the farming community as they are directly and indirectly using major losses to the agricultural system. Reports on economic losses caused by termite infestations have been made worldwide. Intensive use of insecticides which is of great environmental and health concerns was the most frequently control option. To make termites management environmentally friendly, there is a need to integrate indigenous knowledge about pest management techniques into the scaling-up process in order to improve farmers’ pest management practices. For centuries, humans planned agricultural production and conserved natural resources with the instruments of indigenous knowledge (IK). The development of indigenous knowledge systems is cumulative, representing generations of experience, careful observations, trial and error experiments. The objective of this review, we present the available information related to indigenous technology in termite management practices and to identify suitable and sustainable indigenous methods adopted by resource poor farmers for termite control.

Variation in the Susceptibility of Brinjal Shoot and Fruit Borer &lt;i&gt;Leucinodes orbonalis&lt;/i&gt; Guenee to Diamide Insecticides and the Role of Detoxification Enzymes

The susceptibility status of two field populations of brinjal shoot and fruit borer, Leucinodes orbonalis (Guenee) (Lepidoptera: Crambidae) collected from major vegetable growing regions of Kerala (Palakkad and Kollam) was determined during 2022-23 against diamide insecticides viz., flubendiamide 39.35% SC, chlorantraniliprole 18.5% SC, and cyantraniliprole 10.26% OD in comparison to the susceptible population. Palakkad and Kollam populations showed a shift in susceptibility to flubendiamide with an LC50 value of 110.29 ppm and 23.987 ppm, respectively, as compared to that of the susceptible population with an LC50 of 0.504 ppm. Similar trends were observed for chlorantraniliprole and cyantraniliprole in Palakkad population, with an LC50 of 29.194 ppm and 3.399 ppm, respectively. Kollam population also showed a shift in susceptibility to chlorantraniliprole and cyantraniliprole with an LC50 of 2.174 ppm and 0.23 ppm, respectively, as compared to that of the susceptible strain with an LC50 of 0.119 ppm and 0.081 ppm, respectively. The wide range of variation among the field populations’ vulnerability to diamides might be attributed to the differential usage of these insecticides. The increased enzymatic activities of carboxylesterase, glutathione-S-transferase, and cytochrome P-450 monooxygenase in both populations emphasize the importance of detoxification enzymes in the metabolism of xenobiotics. These findings call for the judicious use of diamide insecticides to manage brinjal fruit and shoot borer.

Determination of tomato leafminer: Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) damage on tomato using deep learning instance segmentation method

AbstractPests significantly negatively affect product yield and quality in agricultural production. Agricultural producers may not accurately identify pests and signs of pest damage. Thus, incorrect or excessive insecticides may be used. Excessive use of insecticides not only causes human health and environmental pollution, but also increases input costs. Therefore, early detection and diagnosis of pests is extremely important. In this study, the effectiveness of the instance segmentation method, a deep learning-based method, was investigated for the early detection of the damage caused by the T. absoluta pest in the leaf part of the tomato plant under greenhouse conditions. An original dataset was created by acquiring 800 healthy and damaged images under greenhouse conditions. The acquired images were labelled as bounding box and automatically converted to a mask label with the Segment Anything Model (SAM) model. The created dataset was trained with YOLOv8(n/s/m/l/x)-Seg models. As a result of the training, the box performance of the proposed YOLOv8l-Seg model was measured as 0.924 in the mAP0.5 metric. The YOLOv8l-Seg model mask values are, respectively: mAP0.5, mAP0.5–0.95, Precision, Recall showed the best performance with values of 0.935, 0.806, 0.956 and 0.859. Then, the YOLOv8l-Seg model, trained with different data input sizes, showed the best performance at 640 × 640 size and the lowest performance with a value of 0.699 in the mAP0.5 metric in the 80 × 80 size. The same dataset was trained with YOLOv7, YOLOv5l, YOLACT and Mask R-CNN instance segmentation models and performance comparisons were made with the YOLOv8l-Seg model. As a result, it was determined that the model that best detected T. absoluta damage in tomato plants was the YOLOv8l-Seg model. The Mask R-CNN model showed the lowest performance with a metric of 0.806 mAP0.5. The results obtained from this study revealed that the proposed model and method can be used effectively in detecting the damage caused by the T. absoluta pest.

Biochemistry and transcriptomic analyses of Phthorimaeaabsoluta (Lepidoptera: Gelechiidae) response to insecticides

Phthorimaeaabsoluta is an invasive solanaceous plant pest with highly devastating effects on tomato plant. Heavy reliance on insecticide use to tackle the pest has been linked to insecticide resistance selection in P.absoluta populations. To underline insights on P.absoluta insecticide resistance mechanisms to diamides and avermectins, we evaluated the transcriptomic profile of parental (field-collected) and F8 (lab-reared) populations. Furthermore, to screen for the presence of organophosphate and pyrethroid resistance, we assessed the gene expression levels of acetylcholinesterase (ace1) and para-type voltage-gated sodium channel (VGSG) genes in the F1 to F8 lab-reared progeny of diamide and avermectin exposed P.absoluta field-collected populations. The VGSG gene showed up-regulation in 12.5% and down-regulation in 87.5% of the screened populations, while ace1 gene showed up-regulation in 37.5% and down-regulation in 62.5% of the screened populations. Gene ontology of the differentially expressed genes from both parental and eighth generations of diamide-sprayed P.absoluta populations revealed three genes involved in the metabolic detoxification of diamides in P.absoluta. Therefore, our study showed that the detoxification enzymes found could be responsible for P.absoluta diamide-based resistance, while behavioural resistance, which is stimulus-dependent, could be attributed to P.absoluta avermectin resistance.

Prenatal risk factors of indoor environment and incidence of childhood eczema in the Japan Environment and Children's Study

The quality of indoor environment is a risk factor for early childhood eczema and atopic dermatitis; however, its influence during pregnancy on childhood eczema in Japan has not been investigated. In this study, we aimed to determine the indoor environmental factors that are associated with eczema in children up to 3 years of age, using national birth cohort data from the Japan Environment and Children's Study (JECS).Information on indoor environments and eczema symptoms until 3 years of age was collected using self-administered questionnaires to the mothers. A total of 71,883 and 58,639 mother-child pairs at 1.5- and 3-years-old, respectively, were included in the former analyses. To account for prenatal indoor risk factors, 17,568 (1.5-years-old) and 7063 (3-years-old) children without indoor mold and/or ETS exposure were included in the final analysis. A higher mold index, gas heater use, parquet flooring use, and frequent insecticide use showed significantly increased risks for childhood eczema up to 3 years of age. These associations were consistent after stratification analysis among children whose parents did not have a history of allergies. The updated WHO guidelines on indoor air quality should be implemented based on recent findings regarding the effects of prenatal exposure to indoor dampness on health effects of children further in life, including asthma, respiratory effects, eczema, and other immunological effects.

Low long-lasting insecticidal net use in malaria elimination areas in Southern Ethiopia: results from community based cross-sectional study

BackgroundDespite remarkable progress in malaria burden reduction, malaria continues to be a major public health problem globally. Ethiopia has been distributing long-lasting insecticidal nets (LLINs) for free and nationwide distribution was completed in 2016. However, evidence suggests that the utilization of LLINs varies from setting to setting and from time to time due to different factors, and up-to-date evidence is required for LLIN related decision-making. Hence, this study was designed to assess LLIN utilization and its determinants in the Southern Nations, Nationalities, and People’s Region (SNNPR) of Ethiopia.MethodsA community-based cross-sectional study was conducted in Southern Ethiopia in 2019. Using multi-stage sampling, a total of 2466 households were included. The region was stratified based on the annual malaria index as high, moderate, low, and free strata. Cluster sampling was then applied to select households from high, moderate, and low strata. Data on LLIN ownership, utilization and different determinant factors were collected using household questionnaire. SurveyCTO was used to collect data and data was managed using Stata 15. Descriptive statistics and multilevel mixed-effects logistic regression were performed to identify the determinants of utilization of LLINs. Effect measures were reported using adjusted odds ratio (AOR) with 95% CI.ResultsFrom a total of 2466 households, 48.7% of households had at least one LLIN. LLIN adequacy based on family size was 23% while it was15.7% based on universal access and 29.2% based on sleeping space. From 1202 households that possessed LLIN(s), 66.0% of households reported that they slept under LLIN the night preceding the survey. However, when the total population in all surveyed households were considered, only 22.9% of household members slept under LLIN the night preceding the survey. Malaria endemicity, educational status, wealth status, and knowledge about malaria were associated with LLINs utilization. In addition, reasons for non-use included perceived absence of malaria, side effects of LLIN, conditions of LLINs, inconvenient space and low awareness.ConclusionLow LLIN coverage and low utilization were noted. A low level of utilization was associated with malaria endemicity, wealth status and level of awareness. Distribution of LLIN and continuous follow-up with community awareness creation activities are vital to improve coverage and utilization of LLINs, and to ensure the country’s malaria elimination goal.

Nicotinic Acetylcholine Receptor Alpha6 Contributes to Antiviral Immunity via IMD Pathway in Drosophila melanogaster.

Currently, insecticides that target nicotinic acetylcholine receptors (nAChR) are widely used. Studies on the sublethal effects of insecticides have found that they can affect the amount of virus in insects. The mechanism by which insecticides affect insect virus load remain unclear. Here, we show that nAChR targeting insecticide can affect viral replication through the immune deficiency (IMD) pathway. We demonstrate that a low dose of spinosad (6.8 ng/mL), acting as an antagonist to Drosophila melanogaster nicotinic acetylcholine receptor α6 (Dα6), significantly elevates Drosophila melanogaster sigmavirus (DMelSV) virus titers in adults of Drosophila melanogaster. Conversely, a high dose of spinosad (50 ng/mL), acting as an agonist to Dα6, substantially decreases viral load. This bidirectional regulation of virus levels is absent in Dα6-knockout flies, signifying the specificity of spinosad's action through Dα6. Furthermore, the knockdown of Dα6 results in decreased expression of genes in the IMD pathway, including dredd, imd, relish, and downstream antimicrobial peptide genes AttA and AttB, indicating a reduced innate immune response. Subsequent investigations reveal no significant difference in viral titers between relish mutant flies and Dα6-relish double mutants, suggesting that the IMD pathway's role in antiviral defense is dependent on Dα6. Collectively, our findings shed light on the intricate interplay between nAChR signaling and the IMD pathway in mediating antiviral immunity, highlighting the potential for nAChR-targeting compounds to inadvertently influence viral dynamics in insect hosts. This knowledge may inform the development of integrated pest management strategies that consider the broader ecological impact of insecticide use.

Vectors, knowledge, attitudes, and practices in relation to malaria transmission in Bauchi State, Nigeria.

Malaria remains a major public health concern in Nigeria and the vector (Anopheles species) can only be controlled effectively by having good knowledge of its composition and potential for disease transmission. This work aimed at surveying indoor malaria vectors and, Knowledge, Attitudes, and Practices (KAP) in relation to disease transmission in Toro LGA, Bauchi State, Nigeria. Mosquitoes were collected by Pyrethrum Spray Catch (PSC) between October and December 2019 and were morphologically identified using standard keys. Blood samples were collected from individuals who slept in the rooms where PSC was conducted. Thick and thin blood smears were made for malaria parasite examination. Questionnaires were administered to 120 participants for the KAP studies. Ninety-seven Anopheles mosquitoes were collected and identified as Anopheles gambiae 76 (78.35%), An. funestus 20 (20.62%) and An. coustani 1(1.03%). The overall malaria prevalence was 15.8%. KAP studies revealed that measures and treatment-seeking behaviours against malaria varied significantly (P<0.05) among the respondents. Sleeping under a net 55 (45.8%) and use of insecticides 24 (20.0%) were some of the preventive measures highlighted while the treatment-seeking behaviours included visit to a pharmacy 74 (61.7%) and use of local herbs 11 (9.2%). This work revealed that An. gambiae and An. funestus are predominant malaria vectors in the area. The KAP information demonstrated fair knowledge about the disease by the respondents. Therefore, public enlightenment about malaria prevention, control and treatment is recommended to address the few but highly negative impact knowledge gaps about malaria.

Assessment of the chemical profile and potential biocontrol of Amphora coffeaeformis against foodborne pathogens and Culex pipiens L. to ensure food safety

AbstractThe extensive use of synthetic antibiotics and insecticides in controlling microbes and insect spreads led to a build‐up of resistance strains and caused negative impacts on human health through bioaccumulation in food and the environment. The present study assessed the antimicrobial activity of Amphora coffeaeformis (A. coffeaeformis) ethanolic extract against foodborne pathogenic microbes as well as assessed its ability to control Culex pipiens L. (C. pipiens) larvae. The gas chromatography–mass spectrum (GC/MS) and high‐performance liquid chromatography (HPLC) analysis showed that A. coffeaeformis extract was rich with phenolic compounds, organosulfur compounds, carboxylic acids, amino acids, organic quinoline, dipeptide and monosaccharide. The extract of A. coffeaeformis showed antibacterial capability against all tested bacteria, with minimal inhibition concentration (MIC) values ranging from 20.2 to 66.7 g/mL, as well as antifungal effects against all tested mycotoxigenic fungi, with MIC values ranging from 113.62, 68.95 and 49.37 μg/mL mg/mL. Furthermore, the extract showed high larvicidal activity against C. pipiens larvae at 24, 48, and 72 h, respectively. LC50 values decreased gradually with the treatment period. Likewise, the adult emergence and growth index were significantly negatively related to increasing extract concentrations. Moreover, the extract exhibited a noteworthy depletion in the reproductive potential and increased sterility index of C. pipiens females developed of treated larvae. Besides a reduction in egg hatching percent, increase pupal malformations, increase and adult abnormalities. C. pipiens biochemical markers; glutathione‐S‐transferase, carboxylesterase, acetylcholinesterase, α‐esterase and cytochrome P‐450 showed significant alteration after the extract exposure. Overall, these findings promise the application possibility of A. coffeaeformis extract as a biopreservator against foodborne pathogens and as bioinsecticides for mosquito control as well.

Implementation and effectiveness outcomes of Community Health Advocacy Teams to improve long-lasting insecticide net distribution and use in six districts in Ghana: A one-group pre-post-test study.

Malaria remains a leading cause of illness and death especially among children and pregnant women in Ghana. Despite the efforts made by the National Malaria Elimination Programme (NMEP), including distribution of Long-Lasting Insecticide Nets (LLINs) to households through periodic Point Mass Distribution (PMD) campaigns and continuous channels (antenatal, schools and postnatal), there is a gap between access and use of LLINs in Ghana. An effective and functional community-based group that would seek to improve the effectiveness of LLIN distribution before, during, after PMD Campaigns and continuous distribution at the community level could help address this gap. This paper assesses the implementation outcomes and short-term effectiveness of the pilot implementation of co-created community health advocacy teams (CHAT) intervention in Ghanaian communities to plan and implement campaigns to increase LLIN use. The study employed a one-group pre-post study design and measured implementation outcomes (acceptability, appropriateness, and feasibility) and effectiveness outcomes (LLIN awareness, LLIN access, willingness to purchase LLIN, and LLIN use) among 800 community households. The CHAT intervention was implemented for four months across six districts in the Eastern and Volta regions of Ghana. The data were downloaded directly from REDCap and analyzed statistically (descriptive and McNemar test of association) using SPSS 22 software. After the implementation period, the majority of respondents in all six districts indicated that the CHAT intervention was acceptable (89.8%), appropriate (89.5%), and feasible (90%). Also, there was a significant association between baseline and end-line assessment on all four effectiveness outcome measures. Household members' awareness of, access to, willingness to purchase, and use of LLINs increased significantly over the four-month period that the CHAT intervention was implemented. The study concludes that CHAT is an acceptable, appropriate, and feasible intervention for supporting the National Malaria Programme in LLIN PMD and for engaging in Social and Behaviour Change Communication activities through the continuous channels of distribution. Additionally, the CHAT demonstrates short-term effectiveness outcomes in terms of creating LLIN awareness, providing access to LLIN, and encouraging Ghanaian community members to be willing to purchase and use LLINs. Although the activities of CHAT members were largely voluntary, integration into the existing primary health care system will make it sustainable.

First biochemical and behavioural analysis of the response of the scorpion Urophonius brachycentrus (Thorell: 1876) upon exposure to an organophosphate.

Scorpionism is an increasing public health problem in the world. Although no specific methodology or product is currently available for the control of those arachnids, the use of insecticides could be an effective tool. Chlorpyrifos is one of the insecticides used, but to date, whether scorpions recognise surfaces with that insecticide and how it affects their physiology and/or biochemistry is unknown. In the present study, we observed that scorpions recognise surfaces with 0.51 and 8.59 μg/cm2 of chlorpyrifos and avoid those areas. The 0.51 μg/cm2 concentration produced a decrease in acetylcholinesterase and an increase in catalase, superoxide dismutase and glutathione S-transferase, whereas the 8.59 μg/cm2 concentration evoked a decrease in acetylcholinesterase and an increase in catalase and glutathione S-transferase. Using the comet assay, we observed that the insecticide at 0.17, 0.51 and 8.59 μg/cm2 caused DNA damage. Finally, we found that the insecticide does not generate significant variations in glutathione peroxidase, glutathione reductase, the amount of protein or lipid peroxidation. The present results offer a comprehensive understanding of how scorpions respond, both at the biochemical and behavioural levels, when exposed to insecticides.

White Mustard, Sweet Alyssum, and Coriander as Insectary Plants in Agricultural Systems: Impacts on Ecosystem Services and Yield of Crops

The main reason for adding plants to accompany the main crop is to protect it from pests and diseases. We reviewed the effectiveness of white mustard (Sinapis alba L.), sweet alyssum (Lobularia maritima L.), and coriander (Coriandrum sativum L.) in this regard. White mustard proximity had a strong positive influence on the occurrence of Syrphidae, parasitoids, Coccinellidae, and Carabidae, as well as on the fertility of Syrphidae and the longevity of parasitoids—all of which are essential for biological pest control. It also reduced many pests and diseases. The influence of S. alba on yield depends on the spacing used and the species of protected plant. Sweet alyssum positively affected the occurrence of Syrphidae, Coccinellidae, Anthocoridae, epigeal, and soil fauna, as well as the longevity of parasitoids and Anthocoridae. Its effect on the crop yield is variable, depending on the references consulted. The sensitivity of L. maritima to Phyllotreta spp. excludes it as a companion plant for hosts of these pests. Coriander positively affected the occurrence of Chrysopidae, Coccinellidae, Staphylinidae, and Aranea, as well as the longevity of parasitoids and the egg-laying of Syrphidae. It also reduced some crop pests. Introduction of the reviewed plants can improve the biodiversity of beneficial entomofauna that can help control pests and reduce diseases, with benefits to crop and yield. The use of synthetic insecticides can thus be greatly reduced, though it is not always possible to avoid them completely.

Development and field evaluation of a novel sugar bait device for controlling residential vector mosquitoes in Zhejiang Province, China.

Mosquito-borne diseases pose serious public health threats in Zhejiang Province, China, and vector control is believed to be the primary method for reducing transmission. Due to severe resistance problems, effective and sustainable methods without chemical insecticides are urgently required to control mosquito vectors. Attractive toxic sugar baits (ATSB) are newly developed methods to control mosquitoes in recent decades with the core element sugar bait, which was invented according to the sugar-feeding behavior of mosquitoes. In this study, we developed a Novel Sugar Bait Device (NSBD) trap by combining sugar bait and physical adhesive capture technology. The study aimed to evaluate the effect of the NSBD trap on controlling mosquitoes in residential environments and to identify the optimal sugar solution concentration in the sugar bait of the NSBD for real use. Four residential villages in Ningbo City with similar geographic environments and mosquito densities were selected for field trials in 2022. One village (site 1) was designated as the control group, and three villages (sites 2-4) served as the test groups to assess the effectiveness of NSBD traps with different sugar solution concentrations (6, 8, and 10%) in the sugar bait. Larval and adult mosquito densities were monitored monthly before and semi-monthly after the trials using the CDC light trap and larval pipette method. Before the trials, we monitored mosquito density for 3 months to confirm the baseline mosquito density among the four sites, and no statistical differences in adult and larval mosquitoes were found (adult, F = 3.047, p > 0.05; larvae, F = 0.436, p > 0.05). After the trials, all NCBD traps effectively controlled larval and adult mosquito densities, with the highest standard decrease rates of larval and adult mosquito densities at 57.80 and 86.31%, respectively, observed in site 4. The most suitable sugar solution concentration in the sugar bait was 10%. NSBD traps effectively controlled mosquitoes in residential environments during field trials. Without the use of insecticides, this may be a promising choice for mosquito vector control to prevent mosquito-borne diseases.

Farmers’ Perception Survey and Evaluation of Management Practices for Mango Fruit Borer (Citripestis Eutraphera)

Mango fruit borer (MFB) is a significant pest that damages mango fruits and leaves. This study explores farmers’ perceptions of the mango fruit borer and evaluates management practices. Survey findings indicated that 48% of mango growers believed MFB attacks occur during April-May, while 30% identified May-June as the peak season. Additionally, 84% of mango growers believed MFB affects fruits, while only 2% think it also targeted leaves. Most mango growers (78%) preferred chemical methods to manage MFB, with 40% using bifenthrin, 28% using emamectin benzoate, and only 8% applying imidacloprid. Experiments evaluating MFB’s preference for different mango varieties revealed that nearly all commercial varieties had varying infestation levels. Sindhri was the most infested (29.9%), while Doseri was the least infested (12.6%). Light trap data suggested that the maximum moth population occurred during the last week of April. Evaluations of chemical pesticides showed that bifenthrin (250 ml / 100 L of water) was the most effective, while Thiamethoxam + Chlorantraniliprole (80 ml / 100 L of water) was the least effective for MFB. Emamectin benzoate, Chlorantraniliprole, and Lufenuron were better options than synthetic pyrethroids (Bifenthrin) because they were safer for natural enemies and pollinators. Integrated management strategies, such as installing one light trap per hectare and monitoring MFB on mango leaves and weeds in March/April for early detection, were recommended. Additionally, collecting fallen infested fruits and judicious use of insecticides can help mitigate losses caused by MFB.

Biological Control and Habitat Management for the Control of Onion Thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), in Onion Production in Quebec, Canada.

Onion thrips (Thrips tabaci) can pose a significant threat to onion crops, causing leaf damage, reduced bulb size and quality, and yield loss during severe infestations. Conventional insecticide use has been the primary method for managing this pest species, but the efficacy of this approach is inconsistent. Furthermore, emerging pest resistance is a growing concern in some regions. This two-year field study aimed to assess the effectiveness of several pest management strategies in controlling onion thrips populations and limiting their impact on onion yields. The strategies tested consisted of habitat manipulations (including flower strips and straw mulch), biological control agents (Stratiolaelaps scimitus, Neoseiulus cucumeris, Amblyseius swirskii, and Beauveria bassiana), as well as physical barrier control methods (exclusion nets, kaolin, and mineral oil). Habitat manipulation techniques, particularly the use of flower strips, reduced thrips populations by up to 50% and increased onion yields by 25%. In contrast, exclusion nets had a detrimental effect on onion yields, and the other alternative control methods produced results comparable to those obtained for untreated controls. When used alone, biological control agents were not effective at maintaining thrips populations below economically damaging levels. This study offers valuable insights into effective and sustainable pest management practices for the onion industry.

Oral administration of phytochemicals protects honey bees against cognitive and motor impairments induced by the insecticide fipronil.

Pollution produced by exposure to pesticides is a major concern for food security because the negative impacts on pollinators. Fipronil, an insecticide broadly used around the globe has been associated with the ongoing decline of bees. With a characteristic neuroactive toxicodynamic, fipronil leads to cognitive and motor impairments at sublethal dosages. Despite of regional bans, multilevel strategies are necessary for the protection of pollinators. Recent evidence suggests that specific nutrients in the diets of bees may induce protection against insecticides. Here, we evaluated whether the administration of three phytochemicals, namely rutin, kaempferol and p-coumaric acid provide protection to the Africanized honey bee Apis mellifera against oral administration of realistic dosages of fipronil. We tested the potential impairment produced by fipronil and the protection induced by the phytochemicals in learning, 24h memory, sucrose sensitivity and motor control. We found that the administration of fipronil induced a concentration-dependent impairment in learning and motor control, but not 24h memory or sucrose sensitivity across a 24h window. We also found that the administration of rutin, p-coumaric acid, kaempferol and the mixture was innocuous and generally offered protection against the impairments induced by fipronil. Overall, our results indicate that bees can be prophylactically protected against insecticides via nutrition, providing an alternative to the ongoing conflict between the use of insecticides and the decline of pollinators. As the studied phytochemicals are broadly present in nectar and pollen, our results suggest that the nutritional composition, and not only its production, should be considered when implementing strategies of conservation via gardens and co-cropping.

Sustainability of Theobroma cacao L. production systems in the municipality of Algeciras, Huila, Colombia

This research study evaluated the sustainability of cocoa (Theobroma cacao L.) production systems in the municipality of Algeciras, Huila, under two production models, organic and conventional. The research was carried out with farmers from the Algeciras Producers' Association APROCALG. With the information obtained in the interviews, a group of indicators was designed, classified in three dimensions: ecological, economic and social, in order to identify the sustainability of the production systems from an integral vision. The results showed that both production systems have similarities, since the cultural practices carried out by the farmers are the same; however, the difference is determined by the use of synthetic fertilizers and, in some cases, the use of insecticides to control pests and diseases present in the agroforestry system.

Using stink bug migration behavior for physical exclusion.

Stink bugs have become an increasing concern for tree fruit growers due to changing management strategies and the introduction of an invasive species. The use of broad-spectrum insecticides for stink bug control disrupts biological control and leads to secondary pest outbreaks. To seek alternative tactics, we investigated the physical exclusion of native stink bugs with single-wall net barriers at orchard borders. First, stink bug capture on clear sticky panels along orchard edges showed that movement between the native shrub-steppe vegetation and the orchard occurs for much of the growing season instead of the presumed single migration event in August. Most stink bugs were captured between 1 m and 3 m heights, signifying a 4 m exclusion barrier would intercept migrating bugs. We tested large net barriers (4 m × 23 m) constructed of plain netting with or without deltamethrin-infused netting in flaps compared to a no-net control. The capture of target and nontarget arthropods was determined with plastic tarps below the nets or on the open ground of the control. Net barriers did not directly affect stink bug densities in the orchards, although orchard populations were low overall. Barriers did intercept stink bugs, and the addition of deltamethrin flaps enhanced stink bug mortality but at the price of nontarget arthropod mortality. Our results indicate that stink bug management efforts should focus earlier in the growing season and given the long period of migration, barriers are a more sustainable way of slowing movement into the orchard than the current sole reliance on chemical control.

A dynamic game of lymphatic filariasis prevention by voluntary use of insecticide treated nets

Lymphatic filariasis (LF) has been targeted for elimination as a public health concern by 2030 with a goal to keep the prevalence of LF infections under the 1% threshold. While mass drug administration (MDA) is a primary strategy recommended by WHO, the use of insecticide treated nets (ITN) plays a crucial role as an alternative strategy when MDA cannot be used. In this paper, we use imitation dynamics to incorporate human behavior and voluntary use of ITN into the compartmental epidemiological model of LF transmission. We find the equilibrium states of the dynamics and the ITN usage as it depends on epidemiological parameters and the cost of ITNs. We investigate the conditions under which the voluntary use of ITNs can keep the LF prevalence under the 1% threshold. We found that when the cost of using the ITNs is about 105 smaller than the perceived cost of LF, then the voluntary use of ITNs will eliminate LF as a public health concern. Furthermore, when the ITNs are given away for free, our model predicts that over 80% of the population will use them which would eliminate LF completely in regions where Anopheles are the primary vectors.