Alternative Pest Management Strategies Research Articles

Exploring the efficacy of pyrethroid incorporated nets for the control of stored product moth species: immediate and delayed effects on Ephestia kuehniella and Plodia interpunctella (Lepidoptera: Pyralidae).

Insect pests pose a significant threat to stored commodities, necessitating the exploration of alternative pest management strategies. Long-lasting insecticide-incorporated nets (LLINs) have emerged as a promising tool, offering selectivity and reduced ecological impact compared to conventional chemical approaches. However, their efficacy against Ephestia kuehniella Zeller and Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), cosmopolitan stored product moth species, has remained underexplored. This study investigated the immediate and delayed effects of 2 commercial pyrethroid-incorporated nets, Carifend (0.34% α-cypermethrin) and D-Terrence (0.4% deltamethrin), on the adult and larval stages. Both LLINs demonstrated high efficacy in controlling E. kuehniella and P. interpunctella, with mortality rates reaching up to 100% depending on exposure and post-exposure durations. Particularly, rapid knockdown was observed with D-Terrence net inducing 100% of adults in P. interpunctella after 30min exposure. LLINs achieved almost 100% immediate mortality rate against adults after just 1 day of exposure. In addition, immediate rates of affected individuals reached as high as 81% and 91% in E. kuehniella and P. interpunctella larvae, respectively, following just 5h of exposure to the D-Terrence. Different responses were observed between the adult and larval stages, with larvae exhibiting higher tolerance and potential for recovery from the affected phase after short exposures. There were increasing mortality rates after greater exposure to LLIN. Findings highlight the potential of LLINs as a pest management tool in storage facilities against these important stored product moths. Understanding the responses between life stages and the significance of delayed effects is crucial for optimizing LLIN deployment strategies.

Determinants of oilseed rape-service plant intercropping performance variability across a farmers’ fields network in Western Switzerland

The intercropping of winter oilseed rape with frost-sensitive service plants can provide a diversity of services including weed control and N supply for oilseed rape. This practice started to be adopted by farmers and has therefore become one of the most popular intercropping in Western Europe. However, in Switzerland, such intercropping leads to contrasting yields. The growth of service plants and the benefits they provide have also been found to be variable. The factors explaining these variabilities remain unclear. Our study aimed to better understand this variability under a temperate climate thanks to the regional agronomic diagnosis framework. In this study, we first investigated the main factors explaining this variability and then aimed to rank them to identify ways to better manage such intercropping systems. A network of 28 farmers’ fields planted with winter oilseed rape intercropped with service plant mixtures was studied. Farmers’ practices were diverse in terms of specific composition of the service plant mixture, pest management, and fertilization. We observed that the growth of oilseed rape and service plants in fall was highly variable. We determined that in late fall, the main drivers of the service plant mixture dry weight were specific composition of the mixture and precipitation. The introduction of buckwheat in the service plant mixture enhanced its late fall biomass. The oilseed rape grain yields ranged from 0.4 to 5.0 t ha−1 and were lower than that of the local reference in 75% of the fields. This was mainly explained by insect pest damage in spring due to a very limited use of insecticide in our field network combined with a lack of alternative pest management strategies. This work provides further elements to investigate the causes leading to the high variability we observed, together with the local observations that will benefit the farmers.

Row covers limit pests and disease and increase profit in organic acorn squash

Organic cucurbit growers face many challenges to production including insect pests, insect-vectored diseases, and non-vectored diseases. While Organic Material Review Institute (OMRI) -listed pesticides underperform at suppressing pests and diseases, some alternative pest management strategies hold promise, but little research exists on their cost-effectiveness. We compared the efficacy of mesotunnel systems (nylon-mesh netting row covers deployed over bent metal hoops) and OMRI-listed pesticides (fungicides and insecticides) on acorn squash across 2 years. During the early part of the season, before row covers were removed for pollination, we found 1.7 (2020) and 0.3 (2021) times more cucumber beetles in the uncovered plots compared to the mesotunnels. Powdery mildew incidence was 36 and 25% lower under the mesotunnels compared to the uncovered plots in 2020 and 2021, respectively. Marketable yield of acorn squash was 46–54% higher in the mesotunnels compared to the uncovered treatments. OMRI-listed pesticide treatments reduced powdery mildew incidence compared to untreated control treatments. However, for pest presence, OMRI-listed pesticide treatments did not differ from untreated control treatments in either year, nor did it differ in marketable yield in 2020. Finally, the mesotunnel-only system was 47% more profitable compared to the OMRI-listed pesticide treatment and 47% more profitable compared to the uncovered plots. These results highlight mesotunnels as an economically viable pest management strategy for organic cucurbit growers in the U.S.

Controlling Armyworm (Spodoptera frugiperda) Pest through the Use of Ginger, Garlic, and Chili Powder on Growing Mustasa Plant (June 2023)

Growing in popularity as a sustainable and eco-friendly method of food production is organic agriculture. Organic pesticides have come to light as alternatives to traditional chemical-based pesticides as a result of this trend. Moreover, organic pesticides offer a sustainable method of crop protection that is consistent with organic farming's guiding principles. Because of this, there is rising interest in researching alternative pest management strategies, such as using organic insecticides made from natural ingredients. Allium sativum (garlic), ginger (Gingiber officinale), and chile (capsicum spp.) are well known for their therapeutic and anti- fungal uses. Its potential as an efficient and environmentally friendly pest management method has recently come to light in research. This study was carried out with the intention of repelling and preventing infestations using organic materials in terms of leaves produce, crops yield, and plant survival. The researchers concluded that the level of effectiveness of the preferred concentration was 95% of ginger extract, 5% of garlic extract, and 5% of chili powder is effective with the weighted mean of 6 leaves produce and 30 bunches of crops yield and plant survival

Socio-demographic, agricultural, and personal protective factors in relation to health literacy among farmers from all regions of Thailand.

Farmers are vulnerable to adverse health effects from pesticide exposure due to their health literacy (HL). Therefore, this study aims to investigate HL among farmers in four main regions of Thailand, investigating socio-demographics, agricultural, and personal protective factors to their HL. This cross-sectional design study was conducted on 4,035 farmers from January to July 2023. The European Health Literacy Survey Questionnaire-47 items were used to measure HL. Thai farmers had a mean HL score of 34.7 ± 8.7, and the farmers in the North region of Thailand had the highest frequency of limited HL (75.8%). Socio-demographic factors that were associated with HL included gender, region of living, marital status, education level, co-morbidity, and number of family members. Agricultural factors associated with HL included planting status, working hours on farm, spraying pesticides, harvesting crops, pesticide use of >1 type, access information from government officers, access information from posters/brochures, information from online multimedia, and access information from neighbors. Personal protective factors that were associated with HL included wearing a hat, goggles, a rubber apron, and a long-sleeved shirt. Our study recommends that strategies and interventions to enhance the HL of farmers should be focused on the target populations, which include men, widows, or divorced, those with low levels of education, those who have co-morbidities, and those who applied pesticides of more than 1 type and improper personal protective equipment (PPE) use. The primary emphasis needs to be on the North region of Thailand, making that the target area to improve health equity in Thailand. These efforts would enhance the HL of farmers and sustainably improve pesticide safety behavior. Additionally, there is an urgent need for supportive measures aimed at altering on-farm practices and promoting education on alternative pest management strategies, particularly non-chemical crop protection, to ensure sustainable agriculture.

Low prevalence of secondary endosymbionts in aphids sampled from rapeseed crops in Germany.

Peach-potato aphids, Myzus persicae Sulzer (Hemiptera:Aphididae), and cabbage aphids, Brevicoryne brassicae Linnaeus (Hemiptera:Aphididae), are herbivorous insects of significant agricultural importance. Aphids can harbour a range of non-essential (facultative) endosymbiotic bacteria that confer multiple costs and benefits to the host aphid. A key endosymbiont-derived phenotype is protection against parasitoid wasps, and this protective phenotype has been associated with several defensive enodsymbionts. In recent years greater emphasis has been placed on developing alternative pest management strategies, including the increased use of natural enemies such as parasitoids wasps. For the success of aphid control strategies to be estimated the presence of defensive endosymbionts that can potentially disrupt the success of biocontrol agents needs to be determined in natural aphid populations. Here, we sampled aphids and mummies (parasitised aphids) from an important rapeseed production region in Germany and used multiplex PCR assays to characterise the endosymbiont communities. We found that aphids rarely harboured facultative endosymbionts, with 3.6% of M. persicae and 0% of B. brassicae populations forming facultative endosymbiont associations. This is comparable with endosymbiont prevalence described for M. persicae populations surveyed in Australia, Europe, Chile, and USA where endosymbiont infection frequencies range form 0-2%, but is in contrast with observations from China where M. persicae populations have more abundant and diverse endosymbiotic communities (endosymbionts present in over 50% of aphid populations).

Genetic diversity of diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae) populations in Türkiye.

Diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important worldwide pest of plants belonging to the Brassicaceae family. In this study, we investigated genetic diversity of DBM populations in Brassicaceae production areas in Türkiye using the partial mtDNA CO1 gene region. We determined 43 samples from 11 different populations for haplotype variations using the partial mitochondrial DNA sequences a 684bp fragment of the CO1 gene. The results indicated that, the average haplotype diversity (Hd) was determined as 0.962 and nucleotide diversity (π) was determined as 0.557%. In neutrality tests, negative values were obtained in Tajima's D and Fu' Fs tests (Fu' Fs=-0.40, Tajima's D=-0.01). Tajima's D test was not found significant (p > 0.05). Fst value among DBM population estimates ranged from 0 to 0.631. Barcode gap distance was determined as 1.6%, but the intraspecies of genetic distance were found to be 0.15%. In conclusion, the presented study provided detailed and fundamental information about the genetic diversity of DBM populations in Türkiye. Further studies are needed to develop alternative pest management strategies for DBM populations integrating genetic approaches.

The CsmiR1579-CsKr-h1 module mediates rice stem borer development and reproduction: An effective target for transgenic insect-resistant rice

The rice stem borer (RSB, Chilo suppressalis) is a significant agricultural pest that mainly depends on chemical control. However, it has grown to varied degrees of pesticide resistance, which poses a severe threat to rice production and emphasizes the need for safer, more efficient alternative pest management strategies. Here, in vitro and in vivo experiments analyses reveal miR-1579 binds to the critical transcription factor Krüppel homologue 1 (Kr-h1) and negatively regulates its expression. Overexpression of miR-1579 in larvae with significantly lower levels of Kr-h1 was associated with a decline in larval growth and survival. Furthermore, in female pupae, miR-1579 overexpression led to abnormalities in ovarian development, suggesting that targeting miR-1579 could be a potential management strategy against C. suppressalis. Therefore, we generated transgenic rice expressing miR-1579 and screened three lines that had a single copy of highly abundant mature miR-1579 transcripts. Expectedly, fed with transgenic miR-1579 rice lines were significantly lower survival rates in larvae and high levels of resistance to damage caused by C. suppressalis infestation. These findings suggest that miRNA-mediated RNAi could provide an effective and species-specific strategy for C. suppressalis control.

Field Evaluation of Slow-Release Wax Formulations: A Novel Approach for Managing Bactrocera zonata (Saunders) (Diptera: Tephritidae)

Chemical management of the peach fly, Bactrocera zonata has been compromised due to adverse effects of pesticide residues that not only contaminate environment but also affect non-target organisms including beneficial insects, birds, aquatic life, and soil microorganisms. They can be impacted through direct exposure or by consuming contaminated prey or plants. The present study was designed keeping in view this increasing demand of the consumers to get pesticide residue free fruit and vegetable produce because it reflects the growing consumer concern for food safety and environmental sustainability, motivating the need for alternative pest management strategies. The field experiment was conducted to determine the best slow-release formulation prepared by mixing the following five different types of waxes, including Candelilla wax (CanW), Paraffin wax (PW), Carnauba wax (CarW), Lanolin wax (LW) and Bees wax (BW) with methyl eugenol (ME) (to attract male B. zonata). The selection of the five different types of waxes was likely based on their biodegradability, availability, and potential for slow-release properties. The result revealed that formulations containing SRF-7[LW], SRF-9[CanW], SRF-8[BW], SRF-9[CarW] and SRF-9[PW] exhibited the maximum capture of 42.10 ± 8.14, 43.30 ± 1.76, 34.30 ± 2.96, 35.30 ± 3.18 and 22.70 ± 3.18 male B. zonata per trap per day, respectively. These effective formulations were further evaluated in experiment in which the comparative trapping efficiency of each wax formulation was assessed. The results demonstrated that formulation containing SRF-9[CanW] was expressed maximum capture 13.77 ± 1.26 male B. zonata per trap per day. These formulations were further evaluated in another experiment in which the trapping efficiency was assessed by four different application methods (simple bottle trap, simple bottle trap with water, yellow sticky trap and jute piece with sticky material). The results demonstrated that formulation containing SRF-9[CarW] applied by yellow sticky trap (YST) trapped 61.74 + 7.69 male B. zonata per trap per day and proved more effective. This formulation can be recommended for trapping and management of male population of B. zonata in fruit orchards. This study can influence eco-friendly B. zonata pest control policies, reducing chemical pesticide usage and promoting agricultural sustainability. Future research should study the long-term impact of slow-release formulations on agricultural sustainability, including pest control, crop yield, and agroecosystem health.

Evaluation of Artemisia absinthium L. Essential Oil as a Potential Novel Prophylactic against the Asian Citrus Psyllid Diaphorina citri Kuwayama

Interest in developing novel crop protectants has increased in the recent decade due to the harmful effects of synthetic pesticides on humans and the environment. Diaphorina citri threatens the citrus industry worldwide and is the primary vector of phloem-limited bacterium (HLB). However, there is no available cure for HLB. Diaphorina citri management mainly depends on the use of synthetic insecticides, but their massive application leads to resistance in pest populations. Therefore, alternative pest management strategies are needed. Our results indicated that fewer D. citri adults settled on plants treated with AAEO than on control 48 h after release. The psyllids fed on citrus leaves treated with AAEO significantly reduced the honeydew production compared to the control. The AAEO showed potent ovicidal activity against the D. citri eggs with LC50 5.88 mg/mL. Furthermore, we also explored the fitness of D. citri on AAEO-treated and untreated Citrus sinensis by using two-sex life table tools. Our results revealed that the intrinsic rate of increase (r) was higher on untreated seedlings (0.10 d−1) than those treated with an LC20 concentration of AAEO (0.07 d−1). Similarly, the net reproductive rate (R0) was higher for untreated seedlings (14.21 offspring) than those treated (6.405 offspring). Furthermore, the AAEO were safer against Aphis mellifera, with LC50 35.05 mg/mL, which is relatively higher than the LC50 24.40 mg/mL values against D. citri. The results indicate that AAEO exhibits toxic and behavioral effects on D. citri, which can be a potential candidate for managing this pest.

Farmer’s perception of agrochemical use on honeybees and honey production in Benin: Implication for organic honey production

Beekeeping faces numerous challenges, including the use of agrochemicals. Honeybee colonies are lost because of chemical pesticides use in agriculture to control pests and diseases, which affects detoxifying mechanisms and immune responses, making them more vulnerable to parasites. The purpose of this study was to investigate people’s perception of the impact of agricultural pesticide use on the honeybee community and honey production in northern Benin. A survey was conducted using a questionnaire among 100 beekeepers. Individual interviews were used to gather information on treated crops, the distance between beehives and these cultivated fields, the effect of pesticides and herbicides, alternative methods to pesticide use and honey production. Chemical pesticides such as Callifor G, Kalach, Atrazila 80 WP, Herbextra, Atraforce, Adwumawura (480 SL), Cottonex, Thalis, Cotonix and Cypercal P 330 EC were used in agricultural fields, and beehives were typically found near treated fields. The majority of beekeepers (79%) are aware of the risks associated with pesticides and employ non-pesticide alternatives such as biopesticides to minimize them. In general, beekeepers reported a reduction in the big breed of bees and a 40% decrease in the little breed. When the beehives were placed far away from the treated areas, the honey yield was higher. Alternative pest management strategies to farmers' pesticide use would result in long-term increases in honey production and would constitute the main step of the conversion to organic apiculture in northern Benin.

Intraguild Interactions of Three Biological Control Agents of the Fall Armyworm Spodoptera frugiperda (JE Smith) in Florida.

Simple SummarySpodoptera frugiperda is a native noctuid pest of the Western Hemisphere with a growing global distribution. It is polyphagous by nature and is the primary insect pest attacking maize in Florida. Larval feeding damage has resulted in crop yield losses of up to 20% or more in the United States. In other parts of the world, it causes maize yield losses of between 17–72%. Consequently, regular pesticide applications have led to insecticide-resistant strains of S. frugiperda. Herein, we propose using biological control agents as an alternative pest management strategy. Augmentative biological control allows for the strategic release of these agents where they are sparse or absent in open fields. However, insects are complex organisms with an array of intraguild interactions that might contradict such an effort. Therefore, the goal of improving these agents’ use for alternative pest control requires evaluating their interactions as expressed in the same guild.The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a maize pest worldwide. Its host range comprises more than 350 reported plant species, and it is the primary insect pest attacking maize in Florida. Global trade has not only assisted but accelerated its invasion into the Eastern Hemisphere. Regular pesticide use promotes resistance in the species; therefore, there is an urgent need for alternative pest management strategies. This study evaluated the interactions of biological control agents within a similar guild. Some of the reported interactions could potentially lead to the integration of these agents within the same niche to increase biological control efficiency against the fall armyworm. We evaluated three biocontrol agents that are natural enemies of Lepidopteran pests, the true bugs Podisus maculiventris and Euthyrhynchus floridanus (Hemiptera: Pentatomidae) and a parasitoid, Cotesia marginiventris (Hymenoptera: Braconidae). Depending on their intraguild interactions, these agents could potentially be useful for biological control of the fall armyworm. The study investigated these three biocontrol agents and concluded that integrating these agents to control the fall armyworm is a possibility; however, only under certain conditions. Investigations were focused on evaluating the predator–parasitoid and devised pairing interactions. Predator response to prey in a choice or no-choice scenario and choices based on olfaction or other bodily cues were studied under experimental laboratory conditions.

Biotechnological Approaches for Host Plant Resistance to Insect Pests.

Annually, the cost of insect pest control in agriculture crosses billions of dollars around the world. Until recently, broad-spectrum synthetic pesticides were considered as the most effective means of pest control in agriculture. However, over the years, the overreliance on pesticides has caused adverse effects on beneficial insects, human health and the environment, and has led to the development of pesticide resistant insects. There is a critical need for the development of alternative pest management strategies aiming for minimum use of pesticides and conservation of natural enemies for maintaining the ecological balance of the environment. Host plant resistance plays a vital role in integrated pest management but the development of insect-resistant varieties through conventional ways of host plant resistance takes time, and is challenging as it involves many quantitative traits positioned at various loci. Biotechnological approaches such as gene editing, gene transformation, marker-assisted selection etc. in this direction have recently opened up a new era of insect control options. These could contribute towards about exploring a much wider array of novel insecticidal genes that would otherwise be beyond the scope of conventional breeding. Biotechnological interventions can alter the gene expression level and pattern as well as the development of transgenic varieties with insecticidal genes and can improve pest management by providing access to novel molecules. This review will discuss the emerging biotechnological tools available to develop insect-resistant engineered crop genotypes with a better ability to resist the attack of insect pests.

Black seed and rosemary nanoformulations as green insecticides for the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae).

The development of nano-insecticides has attracted much interest in the last decade because it has the potential to result in an alternative pest-management strategy and also reduce the risk of chemically based insecticides. Herein, native rosemary (Rosmarinus officinalis) and black seed (Nigella sativa) oils were utilized for preparing their nanoemulsions by spontaneous emulsification method in the presence of tween 80 as a structure-directing agent. The prepared nanoemulsions were explored for granary weevil, Sitophilus granarius (L.), adults control and compared with their oils. Within the typical droplet sizes of 100 and 224nm, both rosemary and black seed nanoemulsions were found to be physically and thermodynamically stable. The insecticidal activity of the nanoemulsions was higher than that of the crude oils. After 24h of exposure, the LD50 values of rosemary and black seed nanoemulsions were estimated to be 102.56 and 35.08µg/g, respectively, compared to 188.95 and 210.09µg/g of their oils. These results revealed that the droplet size and chemical composition of the nanoemulsion are the significant factors that affect their toxicity. Surprisingly, the nanoemulsions had no effect on seed germination at LD50 or even LD99 . The utilization of such nanoformulations might open up a new avenue for ecofriendly pest control that is not damaging to humans or the environment, as well as a growing agricultural economy. PRACTICAL APPLICATION: The loss of cereals in postharvesting is one of the major challenges in the world because up to 50% of harvested grains might be destroyed. The intensive usage of chemicals caused harmful effects on humans and the environment. Thus, we prepared rosemary and black seed nanoemulsions and applied them for the grain weevil, S. granarius, control. The results showed superior toxicological efficacy without any effects on seed germination compared with their native oils. Such green strategy could be used instead of chemical insecticides to be environmentally safe for animals and humans.

Biochemical Basis of Synergism between Entomopathogens and Insecticide Spinetoram against Plutella xylostella (L.)

Increasing incidences of insecticide resistance in diamondback moth Plutella xylostella (L.), the most ravaging pest of cruciferous vegetables, have stimulated interest in alternative pest management strategies. In this study, we have developed a spinetoram-resistant population of P. xylostella and examined the single and combined toxicity of Bacillus thuringiensis subsp. kurstaki and Beauveria bassiana with spinetoram. Additionally, enzyme activities were tested to study the influence of biopesticides in the mitigation of detoxifying enzymes. P. xylostella has developed high level of resistance (174.06-fold) against spinetoram after 16 generations of selection. B. thuringiensis subsp. kurstaki and B. bassiana exhibited high toxicity to spinetoram-resistant population of P. xylostella. Synergism was observed between B. thuringiensis subsp. kurstaki + spinetoram and B. bassiana + spinetoram with co-toxicity factor of 30.23 and 22.51, respectively. The joint application of spinetoram + B. bassiana and spinetoram + B. thuringiensis subsp. kurstaki resulted in suppression of mixed-function oxidase activity by 7.93 to 9.23 per cent and carboxyl-esterase activity by 5.64 to 6.18 per cent. Mixtures of biopesticides with spinetoram exhibited synergistic effects and may aid the design of new combinations of management strategies to delay resistant development in P. xylostella.

Understanding the Enemy: A Review of the Genetics, Behavior and Chemical Ecology of Varroa destructor, the Parasitic Mite of Apis mellifera.

Varroa destructor (Mesostigmata: Varroidae) is arguably the most damaging parasitic mite that attacks honey bees worldwide. Since its initial host switch from the Asian honey bee (Apis cerana) (Hymenoptera: Apidae) to the Western honey bee (Apis mellifera) (Hymenoptera: Apidae), Varroa has become a widely successful invasive species, attacking honey bees on almost every continent where apiculture is practiced. Two haplotypes of V. destructor (Japanese and Korean) parasitize A. mellifera, both of which vector various honey bee-associated viruses. As the population of Varroa grows within a colony in the spring and summer, so do the levels of viral infections. Not surprisingly, high Varroa parasitization impacts bees at the individual level, causing bees to exhibit lower weight, decreased learning capacity, and shorter lifespan. High levels of Varroa infestation can lead to colony-wide varroosis and eventually colony death, especially when no control measures are taken against the mites. Varroa has become a successful parasite of A. mellifera because of its ability to reproduce within both drone cells and worker cells, which allows populations to expand rapidly. Varroa uses several chemical cues to complete its life cycle, many of which remain understudied and should be further explored. Given the growing reports of pesticide resistance by Varroa in several countries, a better understanding of the mite’s basic biology is needed to find alternative pest management strategies. This review focuses on the genetics, behavior, and chemical ecology of V. destructor within A. mellifera colonies, and points to areas of research that should be exploited to better control this pervasive honey bee enemy.

Fumigant toxicity of some essential oils and eucalyptol on different life stages of Tribolium confusum (Coleoptera: Tenebrionidae)

ABSTRACT Essential oils of aromatic plants have a high potential for the development of alternative insect pest management strategies. Especially for the control of stored product pests, alternative methods to replace synthetic insecticides are urgently needed. We evaluate the fumigant toxicity of Myrtus communis, Eucalyptus globulus, Syzygium aromaticum, Thymus saturejoides essential oils, and the main natural compound of two of them, eucalyptol, on different life stages of the confused flour beetle (Tribolium confusum) under laboratory conditions. Whereas eucalyptol and the essential oils of M. communis and E. globulus have rather strong toxic effects on all developmental stages, apart from the eggs of T. confusum, the essential oil of S. aromaticum caused the highest egg toxicity. Our results indicate that eucalyptol or essential oils containing large amounts of this compound might be efficient as potential alternative control agents for T. confusum, but tests under more natural conditions need to be performed.

Looking for a sustainable potato crop. Field assessment of early blight management

Potato crops are susceptible to numerous field diseases causing significant losses in the quality and tuber yield. Control measures have a negative impact in soil and water resources affecting also farmers’ health and food security. Hence, a more sustainable agriculture management is a need to preserve ecosystems. Therefore, the objective of this study was to evaluate the response of nine potato cultivars (Fleur Bleue, Frisia, Fontane, Louisa, Agria, Daifla, Red Pontiac, Kennebec and Desiree) against early blight using a Decision Support Systems (DSS) in a potato-producing area from Northwest Spain. The experimental design was established using control plots and sprayed plots with fungicide according to a disease risk model adapted to the geographical region (DSS plots). Disease rating and severity were evaluated in field from the appearance of the first symptoms to final of senescence and the area under disease progress curve (AUDPC and r-AUDPC) was calculated. Aerobiological monitoring of main Alternaria species responsible potato early blight (Alternaria solani and Alternaria alternata) and the most vulnerable phenological stages were also considered. The susceptibility of the potato cultivars was analyzed based on the weather, severity of the disease and tuber yields. Specifically, temperature and leaf wetness were the meteorological variables that most influenced on the concentration of Alternaria. Conidia accounted for the previous week was the variable that most influenced in development of symptoms measured by AUDPC in natural conditions. Yields in the cultivars of DSS plots were higher than in control plots. Therefore, alternative pest management strategies, and specifically, Decision Support Systems for pest assessment are crucial for sustainable potato production. In this sense, the integration of particular information on disease resistance of commercial cultivars, phenological development of plant, or fungal particles surrounding the crop atmosphere could support these systems for better adjustment without compromising tuber yield and environment.

Electrical Stimulation Enhances Plant Defense Response in Grapevine through Salicylic Acid-Dependent Defense Pathway.

Concern over environmental pollution generated by chemical fungicides has led to the introduction of alternative pest management strategies to chemical fungicide application. One of those strategies is the induction of plant defense response by an abiotic elicitor. In the present study, field-grown grapevines were subjected to electrical stimulation using a solar panel from two weeks before flowering to harvest in the 2016 and 2020 growing seasons. In both years, electrical stimulation decreased the incidence of gray mold and/or ripe rot on bunches and downy mildew on leaves of the field-grown grapevine. Transcription of a gene encoding β-1,3-glucanase but not class IV chitinase in leaves of potted grapevine seedlings was upregulated 20 days after electrical stimulation, suggesting that electrical stimulation acts as an abiotic elicitor of plant defense response to fungal diseases. The gene expression of PR1 but not PDF1.2 was upregulated in Arabidopsis plants subjected to electrical stimulation. On the other hand, PR1 gene expression was not induced in salicylic acid (SA)-insensitive Arabidopsis mutant npr1-5 subjected to electrical stimulation. Taken together, electrical stimulation is responsible for plant defense response through the SA-dependent defense pathway. These findings would help us develop a novel and innovative practical technique that uses electrical stimulation in integrated pest management.

Efficacy of Phytoseiulus persimilis and Amblyseius swirskii for integrated pest management for greenhouse cucumbers under Mediterranean environmental conditions

AbstractThe greenhouse cucumber pests, Bemisia tabaci (Hemiptera: Aleyrodidae), Frankliniella occidentalis (Thysanoptera: Thripidae), and Tetranychus urticae (Acari: Tetranychidae), are major threats to the production of greenhouse cucumbers (Cucurbitaceae) in Lebanon. The development of insecticide resistance by these pests has prompted the use of alternative and sustainable pest management strategies. In this study, we used integrated pest management strategies, including the release of the biological control agents, Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae) and Phytoseiulus persimilis Athias-Henriot (Mesostigmata: Phytoseiidae), to control whitefly, thrips, and two-spotted spider mite populations on greenhouse cucumber plants in two commercial production sites (sites A and B). We also compared the efficacy of pest population suppression using the integrated pest management strategy with that of chemical pest control. Our results show that biological control effectively maintains the cucumber pest populations below the economic threshold when coupled with additional integrated pest management measures. In addition, we show that biological control agents were equally or more effective in pest population suppression compared to eight and 12 insecticidal and acaricidal sprays performed in the control greenhouses at sites A and B, respectively. Altogether, our results show the efficacy of adopting integrated pest management and biological control for pest population suppression in greenhouse cucumber production under Mediterranean environmental conditions.