Temperature tolerance and persistence of promising native Metarhizium isolates for use in chili pepper farms in Ghana.

Chili pepper exports from Ghana are subject to stringent chemical residue regulations in key export destinations. Consequently, microbial biopesticides are urgently needed to complement current nonchemical control options for key pests of chili pepper, particularly the phytosanitary insect, False Codling Moth (FCM). Thus, the search for native entomopathogenic fungi in Ghanaian farms was initiated in 2023. Seven Metarhizium isolates (UGSUHCI, UGJKCS9, UGJKCS10, UGAFMF8, UGAFM F12, UGNAKC1 and UGKAP1), obtained from agricultural soils in Ghana, showed high virulence against the soil-dwelling stages of FCM under laboratory conditions. To facilitate the selection of these virulent isolates for development into a mycoinsecticide for FCM, the UV sensitivity and virulence following UV exposure were investigated for all seven isolates in this study. All isolates exhibited extreme susceptibility to UV radiation in comparison to similar research. Exposure to simulated full-spectrum solar radiation at 0.6 W/m2 for 30 min reduced relative conidial germination by 28–40% 48 h following exposure, while 60 min exposure killed all isolates. High insect mortalities were recorded for four isolates, regardless of UV radiation. The findings suggest that an effective UV-protectant formulation could be required for success in the field against fruit and foliar pests of chili pepper, including those of FCM.

The effects of drying on nine pesticides (chlorfenapyr, clothianidin, diethofencarb, folpet, imidacloprid, indoxacarb, methomyl, methoxyfenozide, and tetraconazole) in chili peppers were studied. The mean concentration factor calculated from weight reduction after drying by water loss was 5.28 for field 1 and 5.41 for field 2 (n = 10). Processing factors for pesticide residues in/on chili peppers after drying were 2.45–5.14 for field 1 and 1.71–4.53 for field 2, indicating that pesticide residues remaining in/on chili peppers were concentrated by usual drying process for pepper powder. The reduction factors reflecting net loss of pesticide residues during drying were 0.50–0.98 for field 1 and 0.44–0.98 for field 2. Drying caused a large reduction (37–49 %) in clothianidin, diethofencarb, imidacloprid, and tetraconazole; moderate reductions (16 and 22 %) in methomyl and methoxyfenozide; while did not affect the levels of chlorfenapyr, folpet, and indoxacarb (using conservative higher reduction factors from the two field trials).

Repeated pesticide residue detection in chili peppers in the Republic of Korea has become a serious health concern. Thus, monitoring domestically grown and imported chili peppers for pesticide residues is of great significance. Here, we investigated pesticide residues detected in imported and domestically grown chili peppers using global pesticide residue monitoring data. Our analysis involved organizing inspection and detection data from different sources. Global pesticide residue monitoring data for chili peppers revealed 139 pesticide types, 43,532 inspections, and 3966 detections (detection rate, 9.11%). Peppers from Mexico were sampled the most (39,927 inspections) and showed the highest number of detected cases (2998 cases). Globally, the top 10 most frequently detected pesticides were clothianidin, imidacloprid, thiamethoxam, chlorpyrifos, thiacloprid, metalaxyl, myclobutanil, azoxystrobin, carbendazim, and cyhalothrin, with detection rates in the range of 10.52–28.66%. Furthermore, domestic chili pepper pesticide residue monitoring revealed 73 pesticide types, 3535 inspections, and 332 detected cases (detection rate, 9.39%), and the top 10 most frequently detected pesticides were chlorfenapyr, tebuconazole, flonicamid, dinotefuran, boscalid, pyraclostrobin, fluxametamide, thiamethoxam, pyridaben, and azoxystrobin, with detection rates in the range of 13.89–32.58%. These findings may serve as fundamental data for safety management related to chili pepper pesticide residues in the Republic of Korea.

Entomopathogenic fungi (EPF) are effective and environment-friendly insect biological control agents. Ultraviolet (UV) light is known to have an effect on the survival of fungal conidia, and natural sunlight is potentially one of the most damaging factors undermining EPF persistence and pathogenicity. This study aimed to test the infection potential of an isolate of Beauveria bassiana and five Metarhizium species after exposure to different light treatments, on soil and leaf surfaces under laboratory and field conditions, using Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as the test host. Conidia were exposed either to growth light alone, which emits the same visible light as the sun, but excluding UV light, or directly exposed to UV light for 12 h. The results indicated no negative effect on the infection potential of the conidia of most species tested. The conidia of the two Metarhizium pinghaense (5HEID and TH149) isolates showed the greatest tolerance to visible light and UV radiation exposure on both soil and leaf surfaces. Exposure of M. pinghaense isolates to visible light on soil surfaces showed pathogenicity of > 80% for both isolates, and of between 58% and 88% after exposure to UV light. On leaf surfaces, three Metarhizium isolates, M. pinghaense (5HEID and TH149) and M. majus (TH153) had > 90% pathogenicity following exposure to UV light, and M. pinghaense (TH149) and M. robertsii (6EIKEN) showed greater tolerance of > 70%, under laboratory conditions. However, the pathogenicity of the EPF isolates was very low in field trials, indicating that further trials on the use of formulations and adjuvants with the isolates are needed to improve long-term persistence and efficacy under field conditions.

Combined use of entomopathogenic fungi and their extracts for the control of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae)

Influence of three diets on susceptibility of selected insecticides and activities of detoxification esterases of Helicoverpa assulta (Lepidoptera: Noctuidae)

A field survey was done in teak (Tectona grandis F.) forests in South India to explore the entomopathogenic effect of Metarhizium anisopliae (Ascomycota: Sordariomycetes) against teak defoliator, Hyblaea puera (Lepidoptera: Hyblaeidae). About 300 soils and infected insect samples were collected during the survey and thirty-six fungal isolates were isolated from soil and insect samples and characterized. The fungi were cultured on PDAY with dodine and antibiotics. Generally, the EPF culture was incubated at 27 °C in darkness for 15 days. Virulence of the Entomopathogenic Fungi (EPF) ability to germinate under cold and heat temperatures was assessed in a culture impregnated with conidia. In the experiment, it was found that for the first time Metarhizium quizhouense, Metarhizium robertsii, and Metarhizium majus species caused significantly higher mortality to hosts. These isolates of M. anisopliae, M. robertsii, M. majus, and M. quizhouense were all considered to be effective virulent and environmentally adaptive. The Metarhizium isolates were recommended as effective bio-control agents through the field investigation of teak defoliator Hyblaea puera from South India forest. This study paves the way to utilize the indigenous isolates of EPF for the control of teak defoliator and to combat the pests thatare resistant to insecticide.

Both cucumber mosaic virus (CMV) and tobacco mosaic virus (TMV) coat protein (CP) genes have been transferred to chilli pepper (Capsicum annuum var. Longunt) cultivar 8212 by a modified procedure of Agrobacterium tumefaciens-mediated transformation using hypocotyl as the explant. PCR analysis revealed the presence of both CMV and TMV CP genes in at least 11 primary transformants out of 49 kanamycin-resistant chili pepper plants. Ten T1 lines from five independent transformation events were identified as putative homozygous transgenic lines based on the rooting assay of their T2 seedlings on the kanamycin-containing media. Integration and expression of CMV CP and TMV CP transgenes in one of the homozygous line, 16-13, were confirmed bySouthern blot, RT-PCR and western blot analyses. Line 16-13 was highly resistant to infection of homologous CMV and TMV strains in greenhouse conditions when successively challenged with CMV and TMV or challenged with TMV alone.Futhermore, field trials on T2, T3 and T4 progenies of Line 16-13 were performed on scales of 123, 300 and 10,000 plants, respectively, in consecutive years 1996, 1997 and 1998 with the permission of the Chinese government authority. The transgenic plants displayed delayed symptom development and significantly milder disease severity in field conditions when compared to untransformed chili pepper plants, resulting in 47 and 110% increase in pepper fruit yield in surveys conducted in 1997 and 1998 trials, respectively. Finally, quality analysis and biosafety assesment were performed on transgenic chili pepper fruit concurrently with the control fruit, and demonstrated that the transgenic chili pepper fruit is substantially equivalent to the non-transgenic pepper in terms of the quality and biosafety when consumed as a food additive.

In a bid to develop technologies that serve grower needs for economic management of pests and diseases of hot pepper (scotch bonnet) while protecting public health and the environment, a study to assess the potential of cover cropping and/or less-risk pesticide usage in the management of pests and diseases of hot pepper was conducted for two consecutive seasons in Uganda. A split-plot randomized complete block design with three replications was used with cropping system (main plots) and pesticide treatment (sub-plots) as the factors. There were two cropping systems: the hot pepper þ cowpea system vs. a hot pepper monocrop and five pesticide treatment options: (i) prophylactic treatment of plots at transplanting with granular carbofuran; (ii) weekly sprays of a neem-based formulation; (iii) combination of the prophylactic carbofuran treatment and neem; (iv) sulphur sprays at 10-day intervals (season 2 only); and (v) the untreated control. Data were collected on population dynamics of aphids, whiteflies, thrips, mites, nematodes and on plant performance parameters of branching and fruit weight. Results indicated that the hot pepper þ cowpea system greatly lowered infestations of aphids and nematodes on hot pepper, but did not decrease thrips and whiteflies; and brought about a yield penalty on hot pepper. Prophylactic applications of carbofuran and/or sprays of a neem-based formulation lowered populations of aphids and whiteflies on hot pepper to varying extents; and increased yield of pepper.

Evaluation of convolutional neural network for non-destructive detection of imidacloprid and acetamiprid residues in chili pepper (Capsicum frutescens L.) based on visible near-infrared spectroscopy

为了有效监测农药在蔬菜水果中的残留水平，降低样品基质对目标物的干扰，本研究建立了羧基化多壁碳纳米管（MWCNTs-COOH）改进的QuEChERS联合GC-MS/MS技术对蔬菜水果中34种农药及代谢物残留的高通量检测方法。通过优化前处理过程及色谱、质谱分析条件，确定了蔬菜水果中34种农药及代谢物的最佳检测条件。具体方法如下：蔬菜水果样品经研磨粉碎，加入陶瓷均质子及QuEChERS EN-提取包，振荡离心后，取上清液转移至添加10 mg MWCNTs-COOH的净化管中，振荡离心后取2 mL上清液氮吹至近干，用含有内标的乙酸乙酯复溶，样品经0.22 μm尼龙微孔滤膜过滤后，经Agilent HP-5MS UI气相色谱柱（30 m×0.25 mm×0.25 μm）程序升温分离，GC-MS/MS多反应监测（MRM）模式检测，基质匹配内标法定量。在优化的实验条件下，34种农药及代谢物在相应的线性范围内呈良好的线性关系，相关系数均大于0.997 4，此方法具有较低的检出限（LOD：0.023～0.817 μg/kg）和定量限（LOQ：0.077～2.696 μg/kg）。在低、中、高3个加标水平下，34种农药及代谢物的加标回收率为78.9%～104.5%，相对标准偏差（RSD）为1.0%～7.8%。本方法净化效果显著，准确高效，适用于蔬菜水果中多组分农药及代谢物残留的检测。

The use of pesticides is often the primary choice to protect chili pepper plants (Capsicum frutescens L.) from damage caused by pests and diseases. However, excessive and uncontrolled use of pesticides can lead to pesticide residues adhering to the chili peppers (Capsicum frutescens L.). This research is descriptive quantitative, involving a laboratory experiment that uses gas chromatography-mass spectrometry (GC-MS) to measure the amount of pesticide residues on chili peppers (Capsicum frutescens L.). The study found that insecticides with active ingredients Chlorpyrifos and Profenofos are the most frequently used by farmers, with applications occurring twice a week. The levels of pesticide residues on chili peppers (Capsicum frutescens L.) show significant variation among samples. Based on the results and discussion, it can be concluded that: the average residue level of Chlorpyrifos on chili peppers sold at Keputran Surabaya market is 3.13 ppm, while Profenofos has an average of 3.25 ppm. Furthermore, the average residue level of Chlorpyrifos in the chili pepper samples from Keputran Market in Surabaya exceeds the Maximum Residue Limit (MRL) established by the Indonesian National Standard (SNI), which is 0.5 ppm. Additionally, the average residue level of Profenofos also exceeds the established MRL, which is 2.0 ppm.

The fruit borer (Helicoverpa armigera Hubner) is one of the key pests of chili pepper in Indonesia. Yield loss due to this insect pest may reach up to 60%. Chemical treatment for con-trolling this insect pest is ineffective and eventually leads to environmental pollution. More environmentally safe insecticides are developed based on natural plant ingredients as their active compound such as essential oils. This study aimed to assess the potential of citronella oil for managing H. armigera on chili pepper. The experiments were conducted at the Indonesian Vegetables Research Institute from April 2009 to March 2010 and in Cirebon, West Java from November 2009 to March 2010. A field experiment was designed in a randomized complete block design with five treatments and replicated five times. Citronella oil was extracted by steam distillation from Cymbo-pogon nardus. The oil was then chemically characterized by using GC-MS and its efficacy (ovicidal and feeding deterrent) against H. armigera was tested both in laboratory and field conditions. The GC-MS result showed that major chemical compounds of the citronella oil used were citronella (35.97%), nerol (17.28%), citronellol (10.03%), geranyle acetate (4.44%), elemol (4.38%), limonene (3.98%), and citronnellyle acetate (3.51%). The laboratory experiment revealed that the highest concentration (4,000 ppm) of citronella oil reduced egg laying by 53-66%. Ovicidal activity was concentration dependent, and egg hatchability decreased by 15-95% compared to control. The field experiment showed that treatment of citronella oil at 2.0 mL L-1 significantly reduced fruit damage by H. armigera similar to the plots treated with spinosad at the recommended dose (60 g ai ha-1). Application of citronella oil significantly reduced fruit damage by 72% and increased quality of the chili pepper. Because oviposition and feeding deterrent properties are key factors in controlling the pest, therefore this study revealed that citronella oil has potential to be incorporated into the controlling program of H. armigera on chili pepper.<br /><br /><br />

Spain is the number one citrus-producing country in the European Union and the sixth worldwide, with more than six million tons of citrus produced annually. Seven biorational insecticides (paraffin oil, azadirachtin, kaolin, garlic extract, orange oil, potassium soap and diatomaceous earth) recommended for control of different pests in organic citrus orchards were evaluated against Trioza erytreae (Del Guercio) in semi-field and field trials. All products affected T. erytreae survival in both types of trials. In the semi-field trial, diatomaceous earth resulted in the highest percentage mortality of T. erytreae nymphs, followed by kaolin, apart from on the final day of assessment when the highest mortality was recorded for paraffin oil, though this effect was not significantly different to that of the other insecticides. In the 2018 field trial, orange oil treatment resulted in the highest mortality rate of T. erytreae nymphs, followed by azadirachtin and garlic extract. This work provides citrus growers with useful information on the effects of several biorational insecticides on T. erytreae under field and semi-field conditions. Overall, the optimal T. erytreae nymph mortality was achieved with diatomaceous earth and orange oil under semi-field and field conditions, respectively.

Chemical pesticides have been used for pest control for many decades, but they cause serious problems, including insecticide resistance, secondary pest resurgence, and negative environmental impacts. Therefore, sustainable alternatives to chemical pesticides are necessary for pest control. Entomopathogenic fungi (EPF) are natural epizootic pathogens of insects, and some of them have been used as microbial biocontrol agents. Herein, we attempted to construct an entomopathogenic fungal library (EFLib) via the “Tenebrio molitor pathogenicity-based fungal collection method (TmPC)” to select EPF for control of the serious agricultural pest Spodoptera litura. A total of 172 soil samples were collected in northern and central Taiwan for the EFLib construction. The isolation efficiency of TmPC was 64.02%. The EFLib consisted of 101 isolates and was designated as the National Chung Hsing University (NCHU) EFLib. Among these isolates, 26 showed high virulence (mortality = 100%) to T. molitor larvae. Based on the results of molecular identification, the highly virulent isolates belonged to seven genera, including Beauveria, Clonostachys, Fusarium, Cordyceps, Penicillium, Purpureocillium, and Metarhizium. To evaluate the potential of these isolates for Spodoptera litura control, 12 isolates were selected for pathogenicity screening against S. litura larvae. A total of six EPF isolates belonging to the genera Beauveria and Metarhizium showed rapid eradication of the S. litura larvae. To rank the potential of these fungal strains for pest management, the six isolates were subjected to thermotolerance and conidial production assays, and a novel effective conidia number (ECN) formula was applied. The results indicated that the ECN index of Beauveria australis (NCHU-113) was much higher than that of Metarhizium isolates. However, among the Metarhizium isolates, NCHU-95 showed the highest ECN index. Altogether, NCHU-69 and NCHU-113 should be further tested in field trials. To our knowledge, this is the first attempt to integrate pathogenicity or virulence and ECN data into EPF screening and ranking, providing a baseline for mass selection of potential EPF strains for further applications.