Defense Responses in the Interactions between Medicinal Plants from Lamiaceae Family and the Two-Spotted Spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)

This study aimed to determine the effects of plant species on the biological parameters of Tetranychus urticae Koch and the time of mite infestation on plant physiology in Ocimum basilicum L., Melissa officinalis L. and Salvia officinalis L. Mite infestation induced various levels of oxidative stress depending on plant species and the duration of infestation. Host plants affected T. urticae life table parameters. The low level of susceptibility was characteristic of S. officinalis, which appeared to be the least infected plant species and reduced mites demographic parameters. Infested leaves of S. officinalis contained elevated levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) compared to control. In addition, higher membrane lipid peroxidation and higher activity of guaiacol peroxidase (GPX) and lower activity of catalase (CAT) were recorded with a longer mite infestation. In contrast, O. basilicum appeared to be a suitable host on which T. urticae could develop and increase in number. In basil leaves, increasing levels of hydrogen peroxide and MDA with elevated GPX activity and strongly decreased catalase activity were recorded. Knowledge of the differences in mite susceptibility of the tested medicinal plants described in this study has the potential to be applied in breeding strategies and integrated T. urticae pest management in medicinal plant cultivations

Approaches to Integrated Pest Management in Orchards: <i>Comstockaspis perniciosa</i> (Comstock) Case Study

Insect pests have major effects on agricultural production and food supply. Pest control in conventional crop management in orchards is mainly based on agrochemicals, which entails economic, health and environmental costs. Other approaches, such as biological methods or products based on biologically active substances and sex pheromones used for mating disruption, have faced some implementation challenges, particularly in relation to invasive insect species. The key for appropriate insect pest management is to identify the species and understand its biology and behaviour. Pest management systems should monitor, detect and inform fruit growers about changes in insect distribution, population ecology, possible damage level and economic loses. Comstockaspis perniciosa (San José scale—SJS) is a model example of a pest against which the method of integrated pest management should be adopted. This review presents a case study to support this statement

The Variation of Selected Physiological Parameters in Elm Leaves (Ulmus glabra Huds.) Infested by Gall Inducing Aphids

Three aphid species, Eriosoma ulmi (L.), Colopha compressa (Koch) and Tetraneura ulmi (L.) induce distinct gall morphotypes on Ulmus glabra Huds.; opened and closed galls. Because the trophic relationship of aphids and their galls shows that throughout the gall formation aphids can elicit multiple physiological regulations, we evaluated the changes of hydrogen peroxide content (H2O2), cytoplasmic membrane condition, expressed as electrolyte leakage (EL) and concentration of thiobarbituric acid reactive substances (TBARS), as well as, the activity of catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) in gall tissues, as well as, in damaged and undamaged parts of galled leaves. All aphid species increased EL from gall tissues and significantly upregulated APX activity in galls and galled leaves. Alterations in H2O2 and TBARS concentrations, as well as GPX and CAT activities, were aphid- and tissue-dependent. The development of pseudo- and closed galls on elm leaves did not have a clear effect on the direction and intensity of the host plant&rsquo;s physiological response. The different modes of changes in H2O2, TBARS, CAT and GPX were found in true galls of C. compressa and T. ulmi. Generally, physiological alterations in new plant tissues were quite different compared to other tissues and could be considered beneficial to galling aphids

Visitation of <i>Apis mellifera</i> L. in Runner Bean (<i>Phaseolus coccineus</i> L.) and Its Exposure to Seasonal Agrochemicals in Agroecosystems

Plant species and abiotic factors including season appear to be the most important variables influencing the frequency of visits by honeybees (Apis mellifera L.). In the present study, we evaluated the activity of honeybee workers visiting runner bean (Phaseolus coccineus L.) local cultivar ‘Piękny Jaś’. The runner beans are widely cultivated in south-eastern Poland, and are an important forage plant for honeybees in agroecosystems. We aimed at a comprehensive monitoring of the health of colonies and symptoms in A. mellifera in response to acute exposure to pesticides. The most numerous visits of A. mellifera were observed at the highest flower opening of the runner bean. A very weak positive correlation was observed between the number of honeybees on P. coccineus, the number of visited flowers, the time spent per flower and air temperature. The visitation rates of honeybees were more frequent at mid-day and decreased after 15:00. Signs of poisoning were detected in two out of seven apiaries monitored for acute pesticide exposure symptoms on runner bean plantations. The analysis of dead honeybee samples revealed the acute exposure of honeybees to the imidacloprid (neonicotinoid) and chlorpyrifos (organophosphorus) insecticides, which are highly toxic and banned in the European Union. Hazard quotient (HQ) screening showed an elevated burden of imidacloprid and chlorpyrifos corresponding to 7.1% and 10% of the LDD50, respectively, most likely indicating bee poisoning due to chronic exposure to these substances with contaminated food. Noteworthy was the presence of three fungicides that could pose a risk of poisoning in honeybees