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The Colorado potato beetle (CPB) is a serious pest of economically important Solanaceae species. The use of essential oil compounds in pest management has been proposed as an alternative to harmful chemical insecticides that disturb human health and ecosystem functioning. We examined the antifeedant activity of three concentrations (0.125%, 0.25% and 0.5%) of pure camphor and a thujone-camphor mixture against 3rd instar larvae and adults. Their efficacy was evaluated according to the degree of leaf damage and avoidance of treated leaves by the CPB. Treatment of potato leaves significantly reduced leaf damage compared to the control. Leaf protection increased at higher concentrations of the examined compounds. Camphor was more effective against larvae and the thujone-camphor mixture was more effective against adults. Additionally, adults moved faster towards the control leaf disc in the two-choice olfactometer assay if an alternative disc was treated with a thujone-camphor mixture, whereas larvae responded similarly to the two potential repellents. However, after contact with the leaf disc treated with the highest compound concentration, the larvae escaped faster from the thujone-camphor mixture than from pure camphor. In conclusion, both examined compounds are promising eco-friendly antifeedants, but their efficacy depends on the developmental stage of the beetle, compound type and applied concentration.

Food production is challenged by different factors: climate changes, market competitiveness, food safety, public demands, environmental challenges, new and invasive pests, etc. Intensive food production must be protected against pests, which is nowadays impossible with traditional techniques. The use of eco-friendly biopesticides based on essential oils (EOs), plant extracts (PE), and inert dusts appears to be a complementary or alternative methodology to the conventional chemically synthesized insecticides. The use of such biopesticides reduces the adverse pesticide effects on human health and environment. Biopesticides can exhibit toxic, repellent, and antifeeding effects. Development of bio-insecticides tackles the problem of food safety and residues in fresh food. Innovation within this approach is the combination of several types of active ingredients with complementary effects. Essential oils are well-known compounds with insecticide or repellent activities. New approaches, tools, and products for ecological pest management may substantially decrease pesticide use, especially in fruit and vegetable production. A win-win strategy is to find an appropriate nature-based compound having impact on pests, together with pesticide use, when unavoidable. Toxic or repellent activity could be used for pest control in the field conditions, as well as attractiveness of some compounds for mass trapping, before pests cause significant economic damage.

Biopesticides based on plant oils have many ecological advantages in comparison with chemicals. Control of bacterial diseases is very difficult due to antibiotic resistance and ineffectiveness of chemical products, and essential oils offer a promising alternative. Six essential oils extracted from plants originated from Serbia and twenty-two commercial essential oils from Germany and Albania were assayed for inhibitory and lethal activity against bacterial and fungal pathogens in different horticultural systems. Bacteria tested were: Xanthomonas campestris pv. phaseoli (bean blight), Clavibacter michiganensis subsp. michiganensis (bacterial wilt and tomato canker), Pseudomonas tolaasii (mushroom bacterial brown blotch). Various fungal pathogens of cultivated mushroom were investigated: Lecanicillium fungicola var. fungicola (dry bubble), Mycogone perniciosa (wet bubble), Cladobotryum dendroides (cobweb disease), Trichoderma harzianum, Trichoderma atroviride, Trichoderma aggressivum f. europaeum (green mould) and phytopathogen Verticillium albo-atrum (verticillium wilt on pepper). Minimal inhibitory and lethal concentrations were determined by applying a single drop of oil onto the inner side of each plate cover using macrodilution fumigant method. Among all tested substances, the strongest and broadest activity was shown by the oils of oregano (Origanum vulgare) and wintergreen (Gaultheria procumbens) against bacteria. Mint oil (Mentha piperita L.) and cade (Juniperus oxycedrus L.) were the most toxic to pathogenic fungi. Carvacrol (64.0-75.8%) was the dominant component of oregano oils and menthone (37.2%) of mint oil. X. campestris pv. phaseoli, was the most sensitive bacteria to plant essential oils, and the least sensitive was P. tolaasii. The most susceptible fungus to plant essential oils was M. pernicosa, and the least V. albo-atrum. These results imply that oregano, wintergreen, mint and cade oils could contribute to disease control against different horticu

The bean weevil (Acanthoscelides obtectus, Say) is a serious pest of stored bean seeds. Bean weevil control relies heavily on the use of synthetic insecticides. In the search for a sustainable alternative, the residual contact toxicity and anti-oviposition activity of thyme (Thymus vulgaris L.), rosemary (Rosmarinus officinalis L.) and basil (Ocimum basilicum L.) essential oils as well as their dominant components (thymol, alpha-pinene, 1,8-cineole and linalool) were tested against A. obtectus adults. Out of the seven tested botanicals, T. vulgaris oil, thymol and linalool exhibited the highest toxic potential (>90% mortality). Females were less susceptible than males. The insecticidal activity of these botanicals was much greater when they were applied on glass compared to direct application to the bean. All tested botanicals reduced oviposition by bean weevil females. T. vulgaris oil, thymol and a-pinene also deterred bean weevil oviposition, as revealed by a two-choice test. Our research shows that T. vulgaris oil and thymol are promising and sustainable alternatives to synthetic pesticides for protecting stored beans against the bean weevil.

Larvae of gypsy moth (Lymantria dispar L.) are major defoliators of deciduous forests and urban environment. The biological means of regulation of moth population density were incorporated along with conventional treatment in the integrative management concept. The effects of tansy (Tanacetum vulgare L.) essential oil (EO) to gypsy moths were monitored through the effects of residual contact and digestive toxicity on the mortality and development in the second instar larvae, but also through the growth and feeding indices of the fourth instar larvae. Although EO presence didn’t cause residual contact toxicity or significantly affect larval mortality, tested oil notably elongated developmental time by delaying the molting moment and reduced percentage of molted larvae. On the other hand, EO digestion caused significant mortality in the second instar larvae (72% compared to control, at the end of experiment). Digestion of food enriched with tansy oil decreased the efficiency of the diet, and led to reduced mass gain, and therefore induced the delay of the molting moment, or completely stopped molting into the third instar larvae. Besides that, EO reduced the daily mass gain (0.06 mg mg-1 day-1 compared to 0.3 mg mg-1 day-1 in control) and the food consumption rate (0.61 mg mg-1 day-1 compared to 1.23 mg mg-1 day-1 in control) in the fourth instar larvae and caused decrease of the conversion rate of digested food to larvae body mass (10.62% compared to 26.05% in control). Despite that, food assimilation rate to larvae body mass was not significantly decreased, which moderated negative effects of EO digestion as well as reduced food intake.

A faunistic study of the family Elateridae was carried out in Bačka, the north-western district of Vojvodina Province in Serbia, focusing on their preferred habitats and soil types. The survey included four locations with a total of 1059 ha, in which 35 species, belonging to 15 genera of Elateridae, were observed. The frequency of larval and adult forms was 58.94% and 67.40%, respectively, proving that wireworms are regular residents of the area. Regarding habitat preferences, it was shown that a majority of Elateridae species prefer open biotopes and wheat crop, while marsh soil, chernozem and alluvium were the preferred soil types of wireworms.

Bacterial soft-rot disease caused by Pectobacterium carotovorum subsp. carotovorum is a very destructive disease with a diverse host range in agricultural crops, during the plant growth in the field and in storage. Control, usually based on the use of chemical products, is not satisfactory because of their harmful effect on human health and environment, as well as the possibility for pathogen resistance development. Therefore, developing of new natural products (such as essential oils-EOs, plant extracts etc.) with a sufficient efficacy in control of the disease was imposed. The current study included in vitro testing of bactericidal activity of 51 different oils against P. c. subsp. carotovorum, using an agar-diffusion assay. Bacterial suspension was mixed in Nutrient Agar to final concentration of 107 -108 cells/mL and poured in sterilized Petri plates (ø 90 mm). After media solidified, sterile filter paper discs (ø 5 mm) were placed on the surface of the Petri plates and supplemented with 20 µL of each tested oils. The experiment was performed in a completely randomized design. The results were expressed as a width of inhibition zone (mm) and analyzed by one-factor analysis of variance by using the software package Statistica 7.0 (StatSoft, Inc.). Results showed that the 7 most efficient EOs against P. c. subsp. carotovorum (Thymus vulgaris, Cinnamomum cassia, Cassia angustifolia, Origanum vulgare, Boswellia serrata, Eucalyptus globulus, Satureja montana, respectively) achieved inhibition zone greater than 20 mm. Inhibition zones in the range of 15-20 mm were achieved by 8, 10-15 mm by 9, and less than 10 mm by 6 EOs. The rest of 21 Eos did not show any bactericidal effect.

Ethanol solutions of essential oil of Ocimum basilicum and its main component, linalool (both isomer forms), all in three concentrations, as well as botanical standard Bioneem (0.5%), were tested for their toxicity and antifeedant activity against the second instar gypsy moth larvae in the laboratory bioassay. The essential oil of O. basilicum was subjected to gas chromatography analysis, and totally 37 compounds were detected, of which linalool was predominantly present. All tested solutions showed low to moderate larvicidal effect in both residual toxicity test and in chronic larval mortality bioassay. Chronic mortality tests showed that obtained mortality was a consequence of starving rather than ingestion of treated leaves. However, antifeedant index achieved by application of tested solutions in feeding choice assay was remarkable. Foliar application of all tested compounds deterred feeding by L2 in the same percent as Bioneem. Antifeedant index was relatively high at all tested treatments (85-94%); moreover, the larval desensitization to repelling volatiles has not occurred after five days of observation. Low toxic and high antifeedant properties make these plant-derived compounds suitable for incorporation in integrated pest management programs, especially in urban environments.

Toxicity of twenty-two essential oils to three bacterial pathogens in different horticultural systems: Xanthomonas campestris pv. phaseoli (causing blight of bean), Clavibacter michiganensis subsp. michiganensis (bacterial wilt and canker of tomato), and Pseudomonas tolaasii (causal agent of bacterial brown blotch on cultivated mushrooms) was tested. Control of bacterial diseases is very difficult due to antibiotic resistance and ineffectiveness of chemical products, to that essential oils offer a promising alternative. Minimal inhibitory and bactericidal concentrations are determined by applying a single drop of oil onto the inner side of each plate cover in macrodilution assays. Among all tested substances, the strongest and broadest activity was shown by the oils of wintergreen (Gaultheria procumbens), oregano (Origanum vulgare), and lemongrass (Cymbopogon flexuosus. Carvacrol (64.0-75.8%) was the dominant component of oregano oils, while geranial (40.7%) and neral (26.7%) were the major constituents of lemongrass oil. Xanthomonas campestris pv. phaseoli was the most sensitive to plant essential oils, being susceptible to 19 oils, while 11 oils were bactericidal to the pathogen. Sixteen oils inhibited the growth of Clavibacter michiganensis subsp. michiganensis and seven oils showed bactericidal effects to the pathogen. The least sensitive species was Pseudomonas tolaasii as five oils inhibited bacterial growth and two oils were bactericidal. Wintergreen, oregano, and lemongrass oils should be formulated as potential biochemical bactericides against different horticultural pathogens.