scholarly journals Lack of Effects On Bumblebee (Bombus Terrestris) Colony Development And Drone And Queen Production Due To The Insecticide Chlorantraniliprole

2021 ◽  
Author(s):  
Axel Dinter ◽  
Olaf Klein ◽  
Lea Franke
Keyword(s):  
Bombus Terrestris ◽  
Larval Mortality ◽  
Larval Survival ◽  
Flight Activity ◽  
Colony Development ◽  
Growth Stages ◽  
Monitoring Site ◽  
Worst Case ◽  
Set Up ◽  
Spray Applications

Abstract The aim of the study was to investigate the potential impact of the insecticide chlorantraniliprole on queen-right bumblebee (Bombus terrestris) colonies under semi-field conditions in Phacelia tanacetifolia. The P. tanacetifolia crop was grown in soil treated with modelled worst-case 20-year plateau concentration of chlorantraniliprole in the top 20 cm of soil (equivalent to 0.088 mg a.s./kg). Additionally, two chlorantraniliprole spray applications at 60 g a.s./ha were made. In treatment T1 both spray applications took place before P. tanacetifolia flowering at growth stages BBCH 51–55 and BBCH 55–59. In T2 one spray application was conducted before P. tanacetifolia flowering at BBCH 55–59 and one application during P. tanacetifolia flowering and during daily bee flight at BBCH 61–62. The application in the control (C) and reference item treatment (R) (400 g dimethoate a.s./ha) was carried out during full P. tanacetifolia flowering and bumblebee flight. The bumblebee colonies were exposed to the treated flowering P. tanacetifolia crop for 20 days in the tunnels and afterwards the colonies were kept on a monitoring site. Results of this study indicate no significant differences between the chlorantraniliprole groups T1 and T2 and the control regarding all parameters assessed (i.e. adult and larval mortality, flight activity at the hive entrance, colony weight development, condition of the colonies and production of young queens and males). Overall, no effects of chlorantraniliprole on B. terrestris colonies including queen/male production, adult and larval survival, colony development and forager flight activity were found in this worst-case exposure set-up.

Downwind Spray Drift Assessment for Airblast Sprayer Applications in a Modern Apple Orchard System

2021 ◽  
Vol 64 (2) ◽  
pp. 601-613
Author(s):  
Anura P. Rathnayake ◽  
Lav R. Khot ◽  
Gwen A. Hoheisel ◽  
Harold W. Thistle ◽  
Milt E. Teske ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Mechanistic Model ◽  
Apple Orchard ◽  
Growth Stages ◽  
List Type ◽  
Spray Drift ◽  
Worst Case ◽  
Dormant Stage ◽  
Drift Potential ◽  
Spray Applications

HighlightsAirblast sprayer drift potential was evaluated up to 183 m (600 ft) downwind from an orchard edge.A central leader apple orchard was sprayed at dormant and full canopy stage.Higher drift at full canopy stage was likely due to higher wind speeds and lower humidity.String and artificial foliage samplers had higher collection efficiencies than Mylar cards.Abstract. Risk assessment of orchard pesticide spraying is currently based on spray drift estimation using a worst-case scenario (dormant stage). However, most spray applications are conducted during non-dormant canopy growth stages. Such overestimation leads to restrictive operational regulations in pest management activities. Therefore, field data were generated and studied for a mechanistic model that will predict spray drift from airblast spray applications in tree fruit orchards. Spray trials were conducted at dormant and full canopy growth stages in a central leader trained apple orchard. An axial-fan airblast sprayer sprayed fluorescent tracer in the third row from the orchard’s downwind edge, with four passes being one run. A total of 20 runs, i.e., 17 spray runs and three blanks, were performed during each of the two crop growth stages. Mylar cards, artificial foliage (AF), and horizontal strings (HS) were used to quantify drifting spray deposition up to 183 m (600 ft) downwind. Within the orchard, the deposition on card samplers 3 m upwind of the sprayed row was 21.94% ±4.63% (mean ± standard deviation) of applied dose (AD) at dormant stage and 16.02% ±2.86% AD at full canopy stage. Deposition downwind and adjacent (-3 m) to the sprayed row was 17.92% ±2.70% AD and 7.15% ±1.78% AD at dormant and full canopy stages, respectively. Spray drift decreased substantially at the orchard edge to 3.18% ±1.30% AD at dormant stage and 2.30% ±1.16% AD at full canopy stage. Spray drift was very low at 183 m (600 ft) downwind of the orchard, with deposition of 0.002% ±0.003% AD at dormant stage and 0.003% ±0.004% AD at full canopy stage. Deposition data collected at common sampler locations showed that HS and AF samplers collected significantly (p < 0.05) more drifting spray than card samplers. Downwind speeds had a strong linear relationship with spray drift at both growth stages (dormant: R2= 0.80, full canopy: R2= 0.86), while the influence of temperature and humidity could not be directly observed from the collected data. Keywords: Airblast spraying, Deposit samplers, Dormant and full canopy, Drift, Modern orchard systems.

scholarly journals Monitoring compliance with sulfur content regulations of shipping fuel by in situ measurements of ship emissions

2015 ◽  
Vol 15 (17) ◽  
pp. 10087-10092 ◽  
Author(s):  
L. Kattner ◽  
B. Mathieu-Üffing ◽  
J. P. Burrows ◽  
A. Richter ◽  
S. Schmolke ◽  
...  
Keyword(s):  
Sulfur Content ◽  
Air Pollutant ◽  
Monitoring Site ◽  
Data Set ◽  
The North ◽  
Position Data ◽  
Gas Measurements ◽  
Set Up ◽  
Carbon Dioxide Co2

Abstract. In 1997 the International Maritime Organisation (IMO) adopted MARPOL Annex VI to prevent air pollution by shipping emissions. It regulates, among other issues, the sulfur content in shipping fuels, which is transformed into the air pollutant sulfur dioxide (SO2) during combustion. Within designated Sulfur Emission Control Areas (SECA), the sulfur content was limited to 1 %, and on 1 January 2015, this limit was further reduced to 0.1 %. Here we present the set-up and measurement results of a permanent ship emission monitoring site near Hamburg harbour in the North Sea SECA. Trace gas measurements are conducted with in situ instruments and a data set from September 2014 to January 2015 is presented. By combining measurements of carbon dioxide (CO2) and SO2 with ship position data, it is possible to deduce the sulfur fuel content of individual ships passing the measurement station, thus facilitating the monitoring of compliance of ships with the IMO regulations. While compliance is almost 100 % for the 2014 data, it decreases only very little in 2015 to 95.4 % despite the much stricter limit. We analysed more than 1400 ship plumes in total and for months with favourable conditions, up to 40 % of all ships entering and leaving Hamburg harbour could be checked for their sulfur fuel content.

scholarly journals Flight initiation and flight activity in Prostephanus truncatus (Coleoptera: Bostrichidae)

1998 ◽  
Vol 88 (5) ◽  
pp. 545-552 ◽  
Author(s):  
D. Scholz ◽  
C. Borgemeister ◽  
R. H. Markham ◽  
H. M. Poehling
Keyword(s):  
Sex Ratios ◽  
Breeding Site ◽  
Pheromone Trap ◽  
Flight Activity ◽  
Prostephanus Truncatus ◽  
Pheromone Traps ◽  
Set Up ◽  
Trap Catches ◽  
Maize Cobs ◽  
Flight Initiation

AbstractIn an outdoor experimental set-up, the number of Prostephanus truncatus (Horn) flying from maize cobs was recorded over 38 observation weeks. Flight activity in the field was recorded for 50 weeks with three pheromone traps, each placed at c. 100–300 m from the first experimental set-up. Multiple regression analyses revealed that both flight initiation and flight activity were partly influenced by mean temperatures, but were not directly related. Flight initiation was mainly dependent on population density. An additional experiment showed that sex ratios among pheromone trap catches were not correlated with the number of beetles caught; sex ratios were female-biased throughout the year. Seasonal fluctuations in flight activity recorded with pheromone traps are mainly dependent on changes in the number and sizes of beetle populations in a given area, as well as on breeding site availability and suitability.

scholarly journals The effect of molybdenum and boron in soil on the growth and photosynthesis of three soybean varieties

2011 ◽  
Vol 51 (No. 5) ◽  
pp. 197-205 ◽  
Author(s):  
P. Liu ◽  
Y.S. Yang ◽  
G.D. Xu ◽  
Y.H. Shi ◽  
Y.A. Yang ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Photosynthesis Rate ◽  
Growth Stages ◽  
Pot Experiments ◽  
Tolerant Plant ◽  
Set Up ◽  
System Volume

This paper presents a study on growth and photosynthesis response of soybean to Mo and/or B in soil. Pot experiments were set up to examine the effect of Mo and/or B on growth and photosynthesis of three soybean varieties with four treatments (control, +Mo, +B, +[Mo + B]) at various growth stages. The study showed that Mo and/or B increased main length, system volume and dry weight of the roots, aboveground biomass, leaves’ photosynthesis rate of soybean. The variation and interaction between Mo and B in soil was explored with regard to their impact on soybean growth and photosynthesis. There were some dissimilarity in growth and photosynthesis in the plants between the supplements of Mo and B in the soil, and the interrelation between Mo and B in plant and was co-supplementary to each other. Therefore, growth and photosynthesis of the soybean with Mo and B treatments were much more improved than those with Mo or B alone. Besides, some genotypic variation was found in three soybean varieties, in which Zhechun III was the most sensitive and 3811 the most tolerant plant to Mo and B.

The fisheries management implications of maternal-age-dependent larval survival

2006 ◽  
Vol 63 (10) ◽  
pp. 2249-2258 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford
Keyword(s):  
Mortality Rate ◽  
Fisheries Management ◽  
Maternal Age ◽  
Egg Production ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Larval Survival ◽  
Age Effects ◽  
Fishing Mortality ◽  
Black Rockfish

A common goal of conventional fisheries management is to maintain fishing mortality at a rate that ensures an adequate level of lifetime egg production (LEP) for population sustainability. However, larvae from young spawners can experience higher mortality rates than larvae of older spawners, reducing the effect of egg production by young females (hereafter, maternal age effects). This reduction leads to an error in LEP that can be accounted for by reducing the fishing mortality rate, but raises the question of the magnitude of these errors if they are present but not accounted for. Calculations using parameters from a typical long-lived fish demonstrated that maternal age effects resulted in large errors in estimates of lifetime reproduction when there was a large contrast in the larval mortality rate extending over the reproductive life span. Errors were small when maternal age effects reduced the reproductive potential of only the very youngest spawners, at ages when a small fraction of females are mature. A specific example using the empirically derived maternal age effect for black rockfish (Sebastes melanops) indicated that errors in traditional management would be small for this species.

Southern king crab larval survival: from intra- and interfemale variations to a fishery-induced mortality

2020 ◽  
Vol 77 (12) ◽  
pp. 1893-1903
Author(s):  
Pablo Di Salvatore ◽  
Hernán J. Sacristán ◽  
M. Paula Sotelano ◽  
Federico Tapella ◽  
María Gowland-Sainz ◽  
...  
Keyword(s):  
Glycogen Content ◽  
Larval Mortality ◽  
Extended Period ◽  
Free Fall ◽  
Larval Survival ◽  
Aerial Exposure ◽  
Hedging Strategy ◽  
Air Exposure ◽  
King Crab ◽  
Energetic Reserves

The southern king crab (Lithodes santolla) supports one of the most important fisheries in southern South America. Lecithotrophic larvae hatch over an extended period, in which brooding females can be fished, but must be discarded due to regulations. Larval mortality by female fishing was evaluated. Samples of newly hatched zoeae I were obtained the day before (control) and after female treatment (aerial exposure or aerial exposure + free fall). Independently of the mothers’ treatment, larvae survived less than those from the control, explained by the air-exposure effects. The intraclutch variability in larval survival and their variability in energetic reserves were studied. Females were maintained during the hatching period, and zoea I samples were taken during 3 successive days. We found high variation in larval survival within a single egg clutch and between different females, only ascribable to the initial larval glycogen content. The intraclutch variability in larval survival combined with extended hatching may be an adaptation that allows mothers to find an adequate substrate as larvae hatch and may constitute a diversified bet-hedging strategy.

scholarly journals The Effects of Pollen Protein Content on Colony Development of the Bumblebee, Bombus Terrestris L.

2015 ◽  
Vol 59 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Güney Hikmet Baloglu ◽  
Fehmi Gurel
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Bombus Terrestris ◽  
Mass Rearing ◽  
Papaver Somniferum ◽  
Colony Development ◽  
Sinapis Arvensis ◽  
Sugar Syrup ◽  
Pollen Sources ◽  
Ad Libitum

Abstract The effects of pollen protein content on the colony development of Bombus terrestris were investigated by feeding queens and queenright colonies with four different pollen diets. We used three kinds of commercially available pure pollen (Cistus spp. 11.9%, Papaver somniferum 21.4%, and Sinapis arvensis 21.8% crude protein). We also used a mixture which was made up of equal weights of these pure pollens (18.4 % crude protein). All queens and colonies were fed with sugar syrup and pollen diets ad libitum (28 ± 1 ℃, 65 ± 5% RH). Until there were 50 workers reached, colonies fed with the Cistus pollen diet (167.4 ± 28.9 g) consumed significantly more pollen than colonies fed with the Papaver pollen diet (140.7 ± 15.7 g), the mixed pollen diet (136.2 ± 20.1 g) or colonies fed with the Sinapis pollen diet (132.4 ± 22.6 g). The date when there were 50 workers reached was approximately one week later in the colonies fed with the Cistus, and colonies fed with the Papaver diet than in the colonies fed with the Sinapis diet, and for colonies fed with the mixed pollen diets. Considering 8 tested criteria, the best performances were observed using the Sinapis, and using the mixed pollen diets. The lowest performances were observed using the Cistus pollen diet. Results showed that pollen sources play an important role in commercial bumblebee rearing. Results also showed that the polyfloral pollen diets are more suitable for mass rearing of bumblebees than the unifloral pollen diets.

scholarly journals Experience in Rearing Common Carder Bees (Bombus pascuorum Scop.), with Some Notes on Three Similar Species: Shrill Carder Bee (B. sylvarum L.), Red-shanked Carder Bee (B. ruderarius Müll.), and Brown-banded Carder Bee (B. humilis Ill.) (Hymenoptera: Apidae)

2015 ◽  
Vol 63 (5) ◽  
pp. 1535-1542 ◽  
Author(s):  
Vladimír Ptáček ◽  
Alena Votavová ◽  
Olga Komzáková
Keyword(s):  
Bombus Terrestris ◽  
Vegetation Period ◽  
Egg Laying ◽  
Colony Development ◽  
Similar Species ◽  
Sugar Solution ◽  
Rearing Method ◽  
Small Plastic ◽  
Fresh Pollen ◽  
New Generation

The rearing method under controlled conditions known for Bombus terrestris was successful in initiating egg-laying for 83% of B. pascuorum queens. After larvae had hatched, fresh pollen pellets needed to be inserted into brood pockets daily. After the first workers had emerged, colony development was advanced by placing them outdoors and supplying them with a sugar solution and pollen. The bees were able to use tightly pressed pollen from small plastic pots inserted near the brood. This feeding resulted in large colonies that produced dozens of young queens. In contrast, colonies managed in the laboratory were unable to utilize pollen in a similar manner. They raised only a few workers and several queens. Mating young queens was easy. It was stimulated by daylight, but in the case of B. humilis by direct sunshine. Several B. pascuorum and B. sylvarum queens were overwintered and began the new generation under artificial conditions. However, a lack of fresh pollen limited the development of colonies outside of the vegetation period.

scholarly journals Preliminary Design Guidelines for Considering the Vibration and Noise of Low-Speed Axial Fans Due to Profile Vortex Shedding

2022 ◽  
Vol 7 (1) ◽  
pp. 2
Author(s):  
Gábor Daku ◽  
János Vad
Keyword(s):  
Vortex Shedding ◽  
Design Method ◽  
Axial Flow ◽  
Design Guidelines ◽  
Worst Case ◽  
Low Speed ◽  
Increased Risk ◽  
Axial Fans ◽  
Fan Blade ◽  
Set Up

This paper presents a critical overview on worst-case design scenarios for which low-speed axial flow fans may exhibit an increased risk of blade resonance due to profile vortex shedding. To set up a design example, a circular-arc-cambered plate of 8% relative curvature is investigated in twofold approaches of blade mechanics and aerodynamics. For these purposes, the frequency of the first bending mode of a plate of arbitrary circular camber is expressed by modeling the fan blade as a cantilever beam. Furthermore, an iterative blade design method is developed for checking the risky scenarios for which spanwise and spatially coherent shed vortices, stimulating pronounced vibration and noise, may occur. Coupling these two approaches, cases for vortex-induced blade resonance are set up. Opposing this basis, design guidelines are elaborated upon for avoiding such resonance. Based on the approach presented herein, guidelines are also developed for moderating the annoyance due to the vortex shedding noise.

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