Lethal and behavioural toxicity of differently aged insecticide residues on European earwigs (Forficula auricularia) in the laboratory and in the field.

Pesticide residues are an important topic in many environmental studies, but little is known about the effects of pesticide residues of different ages on beneficial arthropods. Therefore, in this study the activity of residues of three different ages of several commonly used insecticides on the behaviour and mortality of European earwigs was evaluated in the laboratory and the effect of the insecticides was verified in the field. All residues of the biorational SpinTor® (spinosad), Radiant SC (spinetoram), and the conventional Steward® (indoxacarb) showed significantly faster mortality progression compared to the control in the laboratory. All the Steward® residues caused a significant wave of erratic behaviour as the earwigs went through a deep and relatively long moribund stage and resurrected. We verified the effects of SpinTor® and Steward® on changes in earwig abundance and their behaviour in the orchard. Earwigs abundance was significantly lower 16 days after application of biorational SpinTor® and conventional Steward® which had a significantly more pronounced and longer lasting effect. The earwig population stabilised by day 53 after the insecticide applications. Field applications of insecticides had no effect on earwig behaviour and sex ratio. Our results show that older residues have a negative effect on European earwigs equal to that of fresh residues, although their degradation should occur. It is interesting to note that biorational insecticides may not be safer than chemical insecticides.

Efficient Modulation and Processing Method for Closed-Loop Fiber Optic Gyroscope with Piezoelectric Modulator.

This paper presents a simple method for compensating the Sagnac phase shift in an interferometric fiber-optic gyroscope (I-FOG) with a piezoelectric modulator. The common advantages of I-FOGs with closed-loop compensation are linearized output characteristics and insensitivity to the light source power, including its time and thermal-induced fluctuations. Whereas closed-loop operation is normally achieved via ramp modulation requiring an electro-optic modulator, all-fiber architectures with a piezoelectric modulator are mostly limited to open loop. Nevertheless, such setups can more conveniently utilize a less expensive single-mode fiber with depolarized light and do not require any custom-made components. The proposed method allows us to combine the advantages of both approaches. Closed-loop compensation is ensured by adding further sinusoidal modulation to the common biasing modulation, such that the Sagnac phase shift is compensated solely at the sampling instants. We describe and experimentally demonstrate the proposed approach, utilizing a test setup to compare our closed-loop solution with open-loop operation. The results denote that the method provides a cost-efficient manner of performance improvement compared to the open-loop I-FOGs based on a piezoelectric modulator.

Synergistic effects of glyphosate formulation herbicide and tank-mixing adjuvants on Pardosa spiders.

Glyphosate-based herbicides are the world's most consumed agrochemicals, and they are commonly used in various agroecosystems, including forests, as well as in urban zones and gardens. These herbicides are sold as formulations containing adjuvants. Other tank-mixing adjuvants (most often surfactants) are commonly added to these formulations prior to application. According to the manufacturers of agrochemicals, such tank mixes (as these are known in agronomic and horticultural practice) have modified properties and perform better than do the herbicides as used alone. The effects of these tank mixes on the environment and on beneficial arthropods are almost unknown. Therefore, we studied whether a herbicide formulation mixed with adjuvant has modified effects on one of the most common genera of ground-dwelling wolf spiders vis-à-vis the herbicide formulation and adjuvants themselves. Specifically, we studied the synergistic effect in the laboratory on the predatory activity (represented by the number of killed flies) of wolf spiders in the genus Pardosa after direct treatment using the glyphosate-based herbicide formulation Roundup klasik Pro®, Roundup klasik Pro® in a mixture with the surfactant Wetcit®, Roundup klasik Pro® in a mixture with the surfactant Agrovital®, and the surfactants alone. We found that pure surfactants as well as herbicide-and-surfactants tank mixes significantly decrease the predatory activity of Pardosa spiders in the short term even as Roundup klasik Pro® did not itself have any such effect. Our results support the hypothesis that plant protection tank mixes may have modified effect on beneficial arthropods as compared to herbicide formulations alone. Therefore, testing of pesticide tank mixes is highly important, because it is these tank mixes that are actually applied to the environment.