Weeds are responsible for a significant proportion of agricultural production losses. Common ragweed (Ambrosia artemisiifolia L.) has become the dominant weed in much of the northern hemisphere over the last century and is projected to further expand northward with climate warming. Not only does it cause damage to agriculture, but it also poses a significant human health risk. With the increasing number of Ambrosia artemisiifolia, around 44 million more people will suffer from ragweed pollen-induced pollinosis in the future just in Europe. The following review provides an overview of the most important and recent research findings on the spread, morphology, life cycle, importance and damage, allelopathic effects, habitat and environmental requirements of common ragweed. These characteristics of the species may explain its success and, based on this knowledge, allow the development of methods for its control.

There are several harmful and yield decreasing arthropod pests, which live within plant tissues, causing almost unnoticeable damage, e.g.Ostrinia nubilalisHbn.,Cydia pomonellaL.,Acanthoscelides obtectusSay. Their ecological and biological features are rather known. The process leading to the damage is difficult to trace by means of conventional imaging techniques. In this review, optical techniques—X-ray, computer tomography, magnetic resonance imaging, confocal laser scanning microscopy, infrared thermography, near-infrared spectroscopy and luminescence spectroscopy—are described. Main results can contribute to the understanding of the covert pest life processes from the plant protection perspective. The use of these imaging technologies has greatly improved and facilitated the detailed investigation of injured plants. The results provided additional data on biological and ecological information as to the hidden lifestyles of covertly developing insects. Therefore, it can greatly contribute to the realisation of integrated pest management criteria in practical plant protection.

Oulema melanopus L. (Coleoptera: Chrysomelidae) is one of the most serious pests of winter wheat that causes peeling of the epidermis and tissue loss. The complex mapping of the physiological responses triggered by O. melanopus as a biotic stressor in winter wheat has not been fully explored with the help of non-invasive imaging and analytical assays, yet. The aim of the present work was to study the effect of O. melanopus on the physiological processes of winter wheat, especially on the extent of lipid peroxidation and antioxidant activity derived from tissue destruction, as well as photosynthetic ability. The results of the measurements enabled the identification of the antioxidant and lipid-oxidation–related physiological reactions, and they were reflected in the dynamics of non-invasive biophoton emissions. Our non-invasive approach pointed out that in the case of O. melanopus infestation the damage is manifested in tissue loss and the systemic signaling of the biotic stress may have reached other plant parts as well, which was confirmed by the results of antioxidant capacity measurements. These results indicate that the plant reacts to the biotic stress at a whole organizational level. We identified that the antioxidant and lipid-oxidation–related physiological reactions were reflected in the dynamics of two aspects of biophoton emission: delayed fluorescence and ultra-weak bioluminescence. Our research further supported that the non-invasive approach to stress assessment may complete and detail the traditional stress indicators.

The invasive Cotton Bollworm (Helicoverpa armigera Hübner, Lepidoptera: Noctuidae) has become a serious pest of several agricultural plants since its first mass occurrence in Hungary (1993). During the decades of the species’ presence in the Carpathian Basin, a remarkable fluctuation was detected in its abundance and flight phenology. We analysed long term light trap records and meteorological data to identify the possible factors behind these fluctuations. This study presents an overview of the areal dispersion and the rate of accumulation and flight phenology of this invasive pest, from its first Hungarian mass occurrence until the present, focusing on the influence of climatic factors on the Hungarian distribution of H. armigera. According to our estimation, this pest occupied 94% of the area of Hungary within eight years. There were significant differences in pest pressure by regions, corroborated by the average number of trapped specimens and the regression coefficients. Fluctuations of specimen numbers in the different years are clearly visible in the flight phenology diagrams, which depend on the rate of the growing abundance. The results indicate that abiotic elements may also play a significant role in the areal dispersion of this important invasive insect.

Sap sucking heteropteran cereal bugs—members of the Eurygaster and Aelia genus—are serious pests of wheat. Moreover, they feed on a variety of gramineous plant species, including rye, barley, oat, maize, and millet. They are widely distributed in the European continent. The purpose of this review paper is two-fold; it summarizes the currently available data on the biological characteristics, the inflicted damage, and their European distribution and, in addition, we aimed to determine their economic importance, based on data available in the current literature. For the most important cereal bug species, we have collected data on their occurrence in Europe to provide a comprehensive picture of their distribution, and characterized them according to their temperature requirements at different life stages. We have also determined the degree of their attachment to wheat as their host plant, examining the synchronization between the pests and the life cycle of the plant. Finally, we compared their migration characteristics. All the above-mentioned characteristics were merged, in order to assess and rank the damage potential of each species.

Sitophilus granarius (L.) is an important pest of stored grain worldwide. In recent years, sustainable methods against it have received attention as grain stock protective means. Our aim was to obtain information about the efficacy of infrared irradiation (IR) against S. granarius in laboratory conditions. The change in adult-activity and median lethal dose (LD₅₀) triggered by IR in S. granarius was examined. The insecticidal efficacy in the infested grains was also analyzed at 12, 24, 48, and 72h following exposure to IR (250W), and the progeny-production was assessed 45 days upon the treatment. Based on our findings, total mortality ensued in a grain stock of 50 g at 412 s and a for 100 g grain at 256 s. A significant increase in S. granarius mortality could be observed in the higher grain weight regime, which can be accounted for by the higher heat-absorbance of objects with higher weight. The activity of pests immediately after the beginning of IR increased and subsequently became moderated. The observation of activity-peak brought about by irradiation contribute to the optimization of chemical intervention. This treatment could provide an effective and sustainable technique in integrated pest management.