A common and convenient way to produce O2 is photosensitization in the presence of sensitizer

eg with headspace from different numbers of bees indicated that, although one honey bee head space elicited some response in the Varroa leg, only stimuli of 5 and 10 bees evoked significantly higher response than air = 4.75, p = 0.016, ANOVA repeated measures followed by a Bonferroni correction; Disruption of Host Recognition by Varroa Mites Fig. 2C). As 10 bees’ headspace did not add a significant increase in the response amplitude we used the headspace of five bees in further experiments. Varroa responses to sequential stimuli of bee headspace In order to check for a possible habituation of the Varroa MedChemExpress 946128-88-7 foreleg to honey bee volatiles, and the response stability over time, sequential stimuli of five-bee headspace were puffed at intervals of 30 seconds. Comparing the response amplitudes in 7 different Varroa mites, no significant difference was found between the response amplitudes = 0.0407, p = 0.96, ANOVA repeated measures; Fig. S1), and the response remained stable for at least 20 min. The effect of “disrupting”compounds on the Varroa response to bee headspace The disruptive effect of 6 different compounds on the electrophysiological response of Varroa foreleg to honey bee headspace was tested, by sequentially stimulating the foreleg with air, bee headspace or mixed bee headspace + compound stimuli. A significant inhibitory effect on the sensory organ was apparent for most of the tested compounds except for the hexanecontrol and 3c at 10 mg. The impact of the inhibiting compounds on mite responses to honey bee headspace was not the same. A significant short-term inhibitory effect was found for compounds 3c and cy = 8.92, p = 0.002; F = 42.8, p,0.0001), while a significant long-term effect was observed with 3c, cy and the blend, HCO-2169 = 3.89, p = 0.04; F = 19, p,0.0001). This long-term inhibition appeared stronger than the short-term effect for cy and HCO-2-169, but it was eliminated in a fourth stimulation with bee headspace that was applied after stimulation with air. A similar result has been PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19664354 obtained with gypsy moths treated with the sex pheromone, -disparlure, and a blend 3c: the long-term inhibition was reversible, and the response to pure pheromone returned to normal 45 puffs after the mixed puff. In the present study, there were different structure-activity relationships for the short-term and long-term effects. For example, 3c, 3c and cy were similar in their short-term effect, whereas 3c was not active. In terms of the long-term effect the activity was: cy. 3c >3c; 3c was not active. Similarly, in Plettner’s and Gries’ study, the structure-activity relationships differed for short-term and long-term effects. HCO-2-169 is a blend of methyl-substituted cy compounds: cy. To reveal structure-activity relationship of the inhibitory effect, we focused on components of HCO-2-169: cy, cy,cy, cy and cy. The different components as well as the whole mixture were tested in a random order. Except for cy, all of the tested compounds had a long-term inhibiting effect on the Varroa response to bee headspace. The three most effective compounds in that series were: cy, cyand cy = 10.7, p = 0.0009; F = 4.1, p = 0.03; F = 14.6, p = 0.0002). To follow up on the structure-activity relationship of the dialkoxybenzenes, experiments with the three isomers of diethoxybenzene, 3a, 3b and 3c, as well as cy and 3c were performed. The isomers of diethoxybenzene differed in their activity: 3c was the best short-term inhibitor but showed no long-term inh