Contribution to the knowledge of the parasitoid fauna of leaf mining sawflies (Hymenoptera: Tenthredinidae) of forest plants in Hungary

Background and Purpose: Despite the importance of studying the native enemy complex of the introduced and invasive leaf miner sawfly species in their native territories, few studies have been done in recent years concerning the species component and the regulating potential of their parasitoid complexes (in both native and invaded area). Heterarthrus vagans and Fenusa dohrnii are only some of the species which are native in Palearctic area, but alien invasive in North America, causing damage on forest plantations. In this short paper we provide our original data to the knowledge of parasitoid fauna associated with seven leaf mining sawflies native in Hungary. Material and Methods: For a period of four years (2011-2014), several leaf miner species were collected and placed in single mine rearings. From the leafminers, belonging to the Tenthredinidae family, a total of 809 mines made by 9 different species (Heterarthrus wuestneii, Fenusa dohrnii, Heterarthrus vagans, Fenusa pumila, Fenusella nana, Profenusa pygmaea, Metallus pumilus, Parna apicalis, Fenusa ulmi) were collected from 19 locations across Hungary. Results and Conclusion: A total of 188 specimens of 13 parasitoid species belonging to 3 families (Braconidae - 1; Ichneumonidae - 1 and Eulophidae - 11) were reared out from our samples. Parasitoid adults were obtained from 7 of the 9 species of leaf mining sawfly hosts (Fenusa dohrnii, Fenusa pumila, Fenusa ulmi, Heterarthrus vagans, Metallus pumilus, Parna apicalis, Profenusa pygmaea). From Heterarthrus wuestneii and Fenusella nana no parasitoid adults emerged.The parasitoid species presented in this work are typically associated with leaf mining sawflies. Several new host-parasitoid associations have been described

Parasitoid complex of leaf miner Pyllonorycter comparella (Lepidoptera, Gracillariidae) in Hungary

Abstract Between 2011 and 2014, 1,154 mines of Phyllonorycter comparella (Duponchel) were collected at 12 locations in Hungary and were put into single-mine rearing containers. A total of 574 parasitoid specimens belonging to 29 parasitoid species (26 Chalcididae, 2 Encyrtidae and 1 Braconidae) emerged. Of these species, 13 have not yet been mentioned in either international or in Hungarian literature as a parasitoid of the P. comparella. The species assemblages of the parasitoid complexes varied greatly among the sample sites. The primary dominant species of the total samples was found to be Sympiesis sericeicornis (Nees), an abundant idiobiont solitary ectoparasitoid. Among the species reared, we have found specialist parasitoids such as Achrysocharoides scaposa (Erdős) and even species never recorded from Populus (Zagrammosoma variegatum (Masi)) according to the Universal Chalcidoidea Database.</jats:p

Reversed double-beam photoacoustic spectroscopic analysis of photoinduced change in absorption of cellulose fibres

Photoabsorption properties of cellulose fibres under continuous and modulated irradiation were investigated in situ by the use of reversed double-beam photoacoustic spectroscopy (RDB-PAS). This photoacoustic (PA) measurement enabled observation of ultraviolet- and visible light-induced, electron trap filling, and reductive change on the surface of the fibres. Energy-resolved measurements and analysis of the kinetics of photoinduced de-excitation suggested that electrons that accumulated in the different cellulose crystalline phases had moderate reactivity toward molecular oxygen. Saturation limits of the intensities of the PA and RDB-PAS signals under de-aerated conditions in the presence of surface-adsorbed methanol were estimated for softwood and hardwood cellulose samples. The results suggest that the RDB-PAS technique is a feasible method for the estimation of the electron trap distribution, which is a potential measure of the density of crystalline cellulose defects

Using CFD simulations to investigate the shear stress in hydrodynamic cavitation reactors coupled with experimental validation using colony count measurements

The current work investigates the shear stress distribution in hydrodynamic cavitation reactors with two different geometries using CFD simulations. Venturi type (positive geometry) and bore (negative geometry) were used to induce cavitation. Experimental validation of the predictions from simulations was also conducted by calculating the reduction rate in the colony count of Legionella pneumophila , a pathogenic bacterial strain. Both the numerical and experimental studies revealed the significant influence of the shape of the cavitation-inducing geometry on the flow characteristics and the distribution of shear stress. The simulation data indicated high shear stress formation in the positive geometry as a venturi, with the cavitation ranges for the two reactors being far apart from each other. The experimental study also confirmed that the flow conditions in the venturi-type reactor were more favourable compared to the bore geometry, resulting in a bacterial reduction efficiency as high as 99.98%. It was clearly demonstrated that the geometry of the cavitating device plays a crucial role in deciding the shear stress and its efficacy for the desired applications as per the predictions of the simulation model validated by the experimental results