The walnut husk fly (Rhagoletis completa) is one of the main pests affecting common walnut in both Europe and America. This work examines the effects of abamectin on the development of walnut husk fly larvae by injecting the product Vertimec 1.8 EC (Syngenta) into the trunks of walnut trees in Hungary. In the case of properly injected trees, the infection rate was negligible and the abamectin content in the husk samples ranged between 1.54 and 3.00 ng/g; controls show a very high (> 90%) infestation rate and an abamectin content under the detection limit. Abamectin residue measured in walnut kernel did not exceed the maximum residue limit; moreover, the active ingredient content was below the detection limit (0.0003 mg/kg) in all the collected kernel samples. Our results confirm that trunk injection is a viable method for walnut pest control.

The change of the number of turnip moth (Scotia segetum Schiff.) females was examined at 65 different light trap stations between 1957 and 1990. There are two generations of the examined species in Hungary, but the individual number of the first generation is low year by year, so we processed only the data of the second generation.Only those generations were examined that had more than 100 samples because of the statistical reliability. Thirty-three light trap stations were suitable for this examination. The joint number of yearly caught male and female individuals and also separately the samples of females were summarised for each observing station. The change of female individual number as a function of total individual number was determined from the coherent pairs of value. The connection can be described by linear function. The proportion of females is 38%. The relative frequency of females was also determined in the function of the individual number. The shown point-mass is similar to the damped vibration known at technical systems. It was established that the female proportion was higher than the average if the individual number is low, but it showed average value when the individual number was high. It can also be established that the female proportion is significantly high in some cases before gradation years.

This study examined the larvicidal effect of trunk-injected abamectin and emamectin benzoate against the walnut husk fly (Rhagoletis completa Cresson, 1929). Walnut trees in two locations in two years were injected with the pesticides at different concentrations. For the toxicokinetic studies, the active ingredient content was measured in the leaves, flowers, husks, and kernels, using a UHPLC-MS/MS analytical method. The walnut husk fly infestation rates were between 3 and 70% and 10 and 34% for abamectin and emamectin benzoate, respectively, and were much lower compared to those measured for the control. The active ingredient content in the walnut husk showed a positive correlation with the larvicidal effect. The injections had a measurable but unsatisfactory insecticidal effect in the second year, when the economic threshold was exceeded. Trace amounts of the active ingredients were detected in the flowers. The residue analysis showed a declining concentration trend in the leaves over time. The largest quantities were detected in the leaves (≤439 ng/g of abamectin; ≤19,079 ng/g of emamectin benzoate), with concentrations in the husks of orders of magnitude lower (≤5.86 ng/g; ≤50.19 ng/g). The measurements showed no active ingredient residue above the MRLs in either fresh or dried kernels. The results indicate that trunk injections of abamectin, as well as trunk injections of emamectin benzoate, have the potential to suppress walnut husk fly populations.

The paper deals with light trapping of insects during hurricanes. The light-trap is located in Lenoir County, North Carolina, in the United States of America. The geographical coordinates are 35°54′50″N and 81°32′20″W, elevation is 1,171 ft. (357m).We found that on the night of hurricane the catch is zero, or very low, but during the next night, the catch is again high. The same species were caught in the light-traps after the hurricane retreat as in the days before the hurricanes.