In Antarctic summer 1983/1984 samples of planktonie and attached diatoms were collected in the Admiralty Bay (King George Island, South Shetland Islands) as well as samples of planktonie diatoms in the region of South Orkneys, Drake Passage and Bransfield Strait (BIOMASS-SIBEX Project). Using gas chromatography residues of chloroorganic pesticides, namely the compounds of the DDT group and HCH isomers were determined. It was found that the highest values of the content of these compounds occurred in attached diatoms coming from areas continuously washed with water from the melting glacier, in planktonie diatoms from the samples of the Admiralty Bay and from strongly glaciated regions. A hypothesis was put forward that along with the direct atmospheric transport the release of the deposits of these compounds from ice and glaciers during their melting is an additional source of input of chloroorganic biocides into Antarctic waters. Diatoms are good indicators of this process.
Over the two-year study (2008–2009) we monitored the influence of integrated and conventional production systems on microbiological activity in soil and strawberry yield. The experiment also involved fertilizers applied in three variants of treatment. The studied parameters were monitored over 2008 and 2009 by determining the total number of soil microorganisms, the number of ammonifying bacteria and the strawberry yield. The results of the study suggest the pronounced inhibitory effect of insecticides on number of studied microorganism groups in all three conventionally treated variants, over the both years of study, which further infers negligible stimulative influence of strawberry plants on yield.
Concerns about food quality and environmental protection have led to the search for effective and safe insect control measures. This study was carried out to evaluate the efficacy of some insecticides (malathion, alpha-cypermethrin, lambda-cyhalothrin) and clove oil, alone and in combinations, to protect wheat grain against Rhyzopertha dominica. Adult mortality, progeny emergence and weight loss of treated grain were examined. The results revealed that the tested insecticides and clove oil alone showed high efficiency to R. dominica with respect to mortality, progeny of the adults and weight loss of wheat grain. The mixing of lambda-cyhalothrin and clove oil with the most effective insecticide (alphacypermethrin) enhanced its efficacy to R. dominica. It was more efficient against R. dominica than when used alone with respect to mortality and progeny of the adults. However, mixing alpha-cypermethrin with malathion reduced the efficacy of alpha-cypermethrin against R. dominica with respect to mortality and progeny of the adults. Combinations of alpha-cypermethrin and clove oil reduced wheat grain loss more than using them alone. Mixing lambda-cyhalothrin and clove oil with low concentrations of alpha-cypermethrin improved its efficacy against R. dominica and therefore may reduce environmental pollution, lower risks to human health, and delay insect resistance development.
Effective control of Leptinotarsa decemlineata remains an urgent problem for agriculture worldwide. Minimization of the use of non-selective neonicotinoid insecticides, such as thiomethoxam, is an actual vector of development of potato cultivation. In this rapid communication, we show the prospect of the topical use of short unmodified antisense fragment of L. decemlineata CYP6B gene as a DNA insecticide. Investigated parameters, namely, number of larvae per plant, aboveground biomass, yield and number of potatoes produced per plant indicate the possibility of this post-genomic approach as a safe and effective method of L. decemlineata control.