Oviposition activity of Drosophila suzukii as mediated by ambient and fruit temperature.

The invasive pest Drosophila suzukii was introduced to southern Europe in 2008 and spread throughout Central Europe in the following years. Precise reliable data on the temperature-dependent behavior of D. suzukii are scarce but will help forecasting and cultivation techniques. Depending on physico-chemical properties, surface temperature of objects may differ from ambient temperatures, determining physical activity, and affect oviposition on or into substrate, determining preimaginal development later. Therefore, the preferred ambient temperatures of D. suzukii and fruit temperature for oviposition were examined on a linear temperature gradient device. Thirty adults (15 ♀; 15 ♂) were adapted to different temperatures (10, 20, 30°C) for six days and then exposed to different temperature gradients (10-25, 20-35, 25-40°C). D. suzukii adapted to 10°C remained in cooler regions and suffered from a significantly higher mortality at the 25-40°C gradient. Animals adapted to warmer temperatures had a wider temperature preference on the gradient device. Acclimation to lower temperatures and the resulting lower temperature preferences may allow the flies to disperse better in spring to search for oviposition sites. The oviposition activity decreased continuously at a fruit temperature above 28°C and below 15°C, with highest oviposition activity in fruits with temperatures between 19.7°C and 24.8°C. The preferred fruit temperature is in accordance with the temperature optimum of reproduction biology and preimaginal development of D. suzukii reported in the literature

Oekoeffiziente Duenger - Entwicklung zur Minimierung der Stickstoffemissionen in Wasser und Luft Schlussbericht

Feeding the world's population today is due to the use of mineral fertilizers in agriculture. Usually, mineral fertilizers supply nitrogen in form of nitrates which can be leached into the ground water or (after reduction) get lost into the atmosphere as gaseous nitrogen compounds (e.g. N_2O). These losses are on the one hand of ecological concern and on the other hand cause reduced agricultural yields. The development of ecoefficient fertilizers aims at an increase of fertilizer use efficiency and at the same time at a reduction of the ecological problems of nitrogen fertilization. Within the scope of this research and development project new nitrification inhibitors, slow release fertilizers and biodegradable materials as fertilizer coatings were investigated with regard to their chemical, technical and agricultural potential. A new nitrification inhibitor has been developed and already introduced into the market. New slow release fertilizer and coating materials show promising perspectives for a further generation of ecoefficient fertilizers. (orig.)SIGLEAvailable from TIB Hannover: F00B329+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

The development and testing of a new nitrification inhibitor

SIGLEAvailable from British Library Document Supply Centre-DSC:6732.105(no 455) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Fruit temperature preference for oviposition as given by probits, respective cumulated proportion of eggs and corresponding fruit temperature.

<p>(Calculated from equation given in legend <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0187682#pone.0187682.g004" target="_blank">Fig 4</a>).</p

Temperature-dependent oviposition rates of <i>D</i>. <i>suzukii</i>-females on a 12–26°C gradient (open symbols) and on a 18–36°C gradient (closed symbols).

<p>The line represents the calculated Gaussian distribution (h × exp[(−temperature − x0)² ÷ (2 × w²)]; for h = 11.937; x₀ = 23.28; w = 5.486; N = 204; RMSE = 3.798; alpha = 0.05; convergence criterion: 0.00001).</p

Fly mortality (%, mean ± s.e.m.) of conditioned adults in the temperature preference experiments.

<p>(Kruskal-Wallis oneway analysis of variance for mortality per treatment: Chi² = 27.624, p < 0.0006, d.f. = 8; all followed by Wilcoxon each pair test, α = 0.05. n = 5 in all experiments. Different letters indicate statistically significant differences in a line.)</p

Temperature gradient bar, divided into 12 sectors.

<p>Temperature gradient bar, divided into 12 sectors.</p